在做項目的時候，由於我使用到了URL類的反射，然後在Android N上適配發現報錯
No field streamHandlers in class java.net.URL
於是，查看了23和24的源碼，發現URL類有一些變化：
23的源碼如下：
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package java.net;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.Hashtable;
import java.util.jar.JarFile;
import libcore.net.url.FileHandler;
import libcore.net.url.FtpHandler;
import libcore.net.url.JarHandler;
import libcore.net.url.UrlUtils;
/**
* A Uniform Resource Locator that identifies the location of an Internet
* resource as specified by <a href="http://www.ietf.org/rfc/rfc1738.txt">RFC
* 1738</a>.
*
* <h3>Parts of a URL</h3>
* A URL is composed of many parts. This class can both parse URL strings into
* parts and compose URL strings from parts. For example, consider the parts of
* this URL:
* {@code http://username:password@host:8080/directory/file?query#ref}:
* <table>
* <tr><th>Component</th><th>Example value</th><th>Also known as</th></tr>
* <tr><td>{@link #getProtocol() Protocol}</td><td>{@code http}</td><td>scheme</td></tr>
* <tr><td>{@link #getAuthority() Authority}</td><td>{@code username:password@host:8080}</td><td></td></tr>
* <tr><td>{@link #getUserInfo() User Info}</td><td>{@code username:password}</td><td></td></tr>
* <tr><td>{@link #getHost() Host}</td><td>{@code host}</td><td></td></tr>
* <tr><td>{@link #getPort() Port}</td><td>{@code 8080}</td><td></td></tr>
* <tr><td>{@link #getFile() File}</td><td>{@code /directory/file?query}</td><td></td></tr>
* <tr><td>{@link #getPath() Path}</td><td>{@code /directory/file}</td><td></td></tr>
* <tr><td>{@link #getQuery() Query}</td><td>{@code query}</td><td></td></tr>
* <tr><td>{@link #getRef() Ref}</td><td>{@code ref}</td><td>fragment</td></tr>
* </table>
*
* <h3>Supported Protocols</h3>
* This class may be used to construct URLs with the following protocols:
* <ul>
* <li><strong>file</strong>: read files from the local filesystem.
* <li><strong>ftp</strong>: <a href="http://www.ietf.org/rfc/rfc959.txt">File
* Transfer Protocol</a>
* <li><strong>http</strong>: <a href="http://www.ietf.org/rfc/rfc2616.txt">Hypertext
* Transfer Protocol</a>
* <li><strong>https</strong>: <a href="http://www.ietf.org/rfc/rfc2818.txt">HTTP
* over TLS</a>
* <li><strong>jar</strong>: read {@link JarFile Jar files} from the
* filesystem</li>
* </ul>
* In general, attempts to create URLs with any other protocol will fail with a
* {@link MalformedURLException}. Applications may install handlers for other
* schemes using {@link #setURLStreamHandlerFactory} or with the {@code
* java.protocol.handler.pkgs} system property.
*
* <p>The {@link URI} class can be used to manipulate URLs of any protocol.
*/
public final class URL implements Serializable {
private static final long serialVersionUID = -7627629688361524110L;
private static URLStreamHandlerFactory streamHandlerFactory;
/** Cache of protocols to their handlers */
private static final Hashtable<String, URLStreamHandler> streamHandlers
= new Hashtable<String, URLStreamHandler>();
private String protocol;
private String authority;
private String host;
private int port = -1;
private String file;
private String ref;
private transient String userInfo;
private transient String path;
private transient String query;
transient URLStreamHandler streamHandler;
/**
* The cached hash code, or 0 if it hasn't been computed yet. Unlike the RI,
* this implementation's hashCode is transient because the hash code is
* unspecified and may vary between VMs or versions.
*/
private transient int hashCode;
/**
* Sets the stream handler factory for this VM.
*
* @throws Error if a URLStreamHandlerFactory has already been installed
* for the current VM.
*/
public static synchronized void setURLStreamHandlerFactory(URLStreamHandlerFactory factory) {
if (streamHandlerFactory != null) {
throw new Error("Factory already set");
}
streamHandlers.clear();
streamHandlerFactory = factory;
}
/**
* Creates a new URL instance by parsing {@code spec}.
*
* @throws MalformedURLException if {@code spec} could not be parsed as a
* URL.
*/
public URL(String spec) throws MalformedURLException {
this((URL) null, spec, null);
}
/**
* Creates a new URL by resolving {@code spec} relative to {@code context}.
*
* @param context the URL to which {@code spec} is relative, or null for
* no context in which case {@code spec} must be an absolute URL.
* @throws MalformedURLException if {@code spec} could not be parsed as a
* URL or has an unsupported protocol.
*/
public URL(URL context, String spec) throws MalformedURLException {
this(context, spec, null);
}
/**
* Creates a new URL by resolving {@code spec} relative to {@code context}.
*
* @param context the URL to which {@code spec} is relative, or null for
* no context in which case {@code spec} must be an absolute URL.
* @param handler the stream handler for this URL, or null for the
* protocol's default stream handler.
* @throws MalformedURLException if the given string {@code spec} could not
* be parsed as a URL or an invalid protocol has been found.
*/
public URL(URL context, String spec, URLStreamHandler handler) throws MalformedURLException {
if (spec == null) {
throw new MalformedURLException();
}
if (handler != null) {
streamHandler = handler;
}
spec = spec.trim();
protocol = UrlUtils.getSchemePrefix(spec);
int schemeSpecificPartStart = protocol != null ? (protocol.length() + 1) : 0;
// If the context URL has a different protocol, discard it because we can't use it.
if (protocol != null && context != null && !protocol.equals(context.protocol)) {
context = null;
}
// Inherit from the context URL if it exists.
if (context != null) {
set(context.protocol, context.getHost(), context.getPort(), context.getAuthority(),
context.getUserInfo(), context.getPath(), context.getQuery(),
context.getRef());
if (streamHandler == null) {
streamHandler = context.streamHandler;
}
} else if (protocol == null) {
throw new MalformedURLException("Protocol not found: " + spec);
}
if (streamHandler == null) {
setupStreamHandler();
if (streamHandler == null) {
throw new MalformedURLException("Unknown protocol: " + protocol);
}
}
// Parse the URL. If the handler throws any exception, throw MalformedURLException instead.
try {
streamHandler.parseURL(this, spec, schemeSpecificPartStart, spec.length());
} catch (Exception e) {
throw new MalformedURLException(e.toString());
}
}
/**
* Creates a new URL of the given component parts. The URL uses the
* protocol's default port.
*
* @throws MalformedURLException if the combination of all arguments do not
* represent a valid URL or if the protocol is invalid.
*/
public URL(String protocol, String host, String file) throws MalformedURLException {
this(protocol, host, -1, file, null);
}
/**
* Creates a new URL of the given component parts. The URL uses the
* protocol's default port.
*
* @param host the host name or IP address of the new URL.
* @param port the port, or {@code -1} for the protocol's default port.
* @param file the name of the resource.
* @throws MalformedURLException if the combination of all arguments do not
* represent a valid URL or if the protocol is invalid.
*/
public URL(String protocol, String host, int port, String file) throws MalformedURLException {
this(protocol, host, port, file, null);
}
/**
* Creates a new URL of the given component parts. The URL uses the
* protocol's default port.
*
* @param host the host name or IP address of the new URL.
* @param port the port, or {@code -1} for the protocol's default port.
* @param file the name of the resource.
* @param handler the stream handler for this URL, or null for the
* protocol's default stream handler.
* @throws MalformedURLException if the combination of all arguments do not
* represent a valid URL or if the protocol is invalid.
*/
public URL(String protocol, String host, int port, String file,
URLStreamHandler handler) throws MalformedURLException {
if (port < -1) {
throw new MalformedURLException("port < -1: " + port);
}
if (protocol == null) {
throw new NullPointerException("protocol == null");
}
// Wrap IPv6 addresses in square brackets if they aren't already.
if (host != null && host.contains(":") && host.charAt(0) != '[') {
host = "[" + host + "]";
}
this.protocol = protocol;
this.host = host;
this.port = port;
file = UrlUtils.authoritySafePath(host, file);
// Set the fields from the arguments. Handle the case where the
// passed in "file" includes both a file and a reference part.
int hash = file.indexOf("#");
if (hash != -1) {
this.file = file.substring(0, hash);
this.ref = file.substring(hash + 1);
} else {
this.file = file;
}
fixURL(false);
// Set the stream handler for the URL either to the handler
// argument if it was specified, or to the default for the
// receiver's protocol if the handler was null.
if (handler == null) {
setupStreamHandler();
if (streamHandler == null) {
throw new MalformedURLException("Unknown protocol: " + protocol);
}
} else {
streamHandler = handler;
}
}
void fixURL(boolean fixHost) {
int index;
if (host != null && host.length() > 0) {
authority = host;
if (port != -1) {
authority = authority + ":" + port;
}
}
if (fixHost) {
if (host != null && (index = host.lastIndexOf('@')) > -1) {
userInfo = host.substring(0, index);
host = host.substring(index + 1);
} else {
userInfo = null;
}
}
if (file != null && (index = file.indexOf('?')) > -1) {
query = file.substring(index + 1);
path = file.substring(0, index);
} else {
query = null;
path = file;
}
}
/**
* Sets the properties of this URL using the provided arguments. Only a
* {@code URLStreamHandler} can use this method to set fields of the
* existing URL instance. A URL is generally constant.
*/
protected void set(String protocol, String host, int port, String file, String ref) {
if (this.protocol == null) {
this.protocol = protocol;
}
this.host = host;
this.file = file;
this.port = port;
this.ref = ref;
hashCode = 0;
fixURL(true);
}
/**
* Returns true if this URL equals {@code o}. URLs are equal if they have
* the same protocol, host, port, file, and reference.
*
* <h3>Network I/O Warning</h3>
* <p>Some implementations of URL.equals() resolve host names over the
* network. This is problematic:
* <ul>
* <li><strong>The network may be slow.</strong> Many classes, including
* core collections like {@link java.util.Map Map} and {@link java.util.Set
* Set} expect that {@code equals} and {@code hashCode} will return quickly.
* By violating this assumption, this method posed potential performance
* problems.
* <li><strong>Equal IP addresses do not imply equal content.</strong>
* Virtual hosting permits unrelated sites to share an IP address. This
* method could report two otherwise unrelated URLs to be equal because
* they're hosted on the same server.</li>
* <li><strong>The network may not be available.</strong> Two URLs could be
* equal when a network is available and unequal otherwise.</li>
* <li><strong>The network may change.</strong> The IP address for a given
* host name varies by network and over time. This is problematic for mobile
* devices. Two URLs could be equal on some networks and unequal on
* others.</li>
* </ul>
* <p>This problem is fixed in Android 4.0 (Ice Cream Sandwich). In that
* release, URLs are only equal if their host names are equal (ignoring
* case).
*/
@Override public boolean equals(Object o) {
if (o == null) {
return false;
}
if (this == o) {
return true;
}
if (this.getClass() != o.getClass()) {
return false;
}
return streamHandler.equals(this, (URL) o);
}
/**
* Returns true if this URL refers to the same resource as {@code otherURL}.
* All URL components except the reference field are compared.
*/
public boolean sameFile(URL otherURL) {
return streamHandler.sameFile(this, otherURL);
}
@Override public int hashCode() {
if (hashCode == 0) {
hashCode = streamHandler.hashCode(this);
}
return hashCode;
}
/**
* Sets the receiver's stream handler to one which is appropriate for its
* protocol.
*
* <p>Note that this will overwrite any existing stream handler with the new
* one. Senders must check if the streamHandler is null before calling the
* method if they do not want this behavior (a speed optimization).
*
* @throws MalformedURLException if no reasonable handler is available.
*/
void setupStreamHandler() {
// Check for a cached (previously looked up) handler for
// the requested protocol.
streamHandler = streamHandlers.get(protocol);
if (streamHandler != null) {
return;
}
// If there is a stream handler factory, then attempt to
// use it to create the handler.
if (streamHandlerFactory != null) {
streamHandler = streamHandlerFactory.createURLStreamHandler(protocol);
if (streamHandler != null) {
streamHandlers.put(protocol, streamHandler);
return;
}
}
// Check if there is a list of packages which can provide handlers.
// If so, then walk this list looking for an applicable one.
String packageList = System.getProperty("java.protocol.handler.pkgs");
ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
if (packageList != null && contextClassLoader != null) {
for (String packageName : packageList.split("\\|")) {
String className = packageName + "." + protocol + ".Handler";
try {
Class<?> c = contextClassLoader.loadClass(className);
streamHandler = (URLStreamHandler) c.newInstance();
if (streamHandler != null) {
streamHandlers.put(protocol, streamHandler);
}
return;
} catch (IllegalAccessException ignored) {
} catch (InstantiationException ignored) {
} catch (ClassNotFoundException ignored) {
}
}
}
// Fall back to a built-in stream handler if the user didn't supply one
if (protocol.equals("file")) {
streamHandler = new FileHandler();
} else if (protocol.equals("ftp")) {
streamHandler = new FtpHandler();
} else if (protocol.equals("http")) {
try {
String name = "com.android.okhttp.HttpHandler";
streamHandler = (URLStreamHandler) Class.forName(name).newInstance();
} catch (Exception e) {
throw new AssertionError(e);
}
} else if (protocol.equals("https")) {
try {
String name = "com.android.okhttp.HttpsHandler";
streamHandler = (URLStreamHandler) Class.forName(name).newInstance();
} catch (Exception e) {
throw new AssertionError(e);
}
} else if (protocol.equals("jar")) {
streamHandler = new JarHandler();
}
if (streamHandler != null) {
streamHandlers.put(protocol, streamHandler);
}
}
/**
* Returns the content of the resource which is referred by this URL. By
* default this returns an {@code InputStream}, or null if the content type
* of the response is unknown.
*/
public final Object getContent() throws IOException {
return openConnection().getContent();
}
/**
* Equivalent to {@code openConnection().getContent(types)}.
*/
@SuppressWarnings("unchecked") // Param not generic in spec
public final Object getContent(Class[] types) throws IOException {
return openConnection().getContent(types);
}
/**
* Equivalent to {@code openConnection().getInputStream(types)}.
*/
public final InputStream openStream() throws IOException {
return openConnection().getInputStream();
}
/**
* Returns a new connection to the resource referred to by this URL.
*
* @throws IOException if an error occurs while opening the connection.
*/
public URLConnection openConnection() throws IOException {
return streamHandler.openConnection(this);
}
/**
* Returns a new connection to the resource referred to by this URL.
*
* @param proxy the proxy through which the connection will be established.
* @throws IOException if an I/O error occurs while opening the connection.
* @throws IllegalArgumentException if the argument proxy is null or of is
* an invalid type.
* @throws UnsupportedOperationException if the protocol handler does not
* support opening connections through proxies.
*/
public URLConnection openConnection(Proxy proxy) throws IOException {
if (proxy == null) {
throw new IllegalArgumentException("proxy == null");
}
return streamHandler.openConnection(this, proxy);
}
/**
* Returns the URI equivalent to this URL.
*
* @throws URISyntaxException if this URL cannot be converted into a URI.
*/
public URI toURI() throws URISyntaxException {
return new URI(toExternalForm());
}
/**
* Encodes this URL to the equivalent URI after escaping characters that are
* not permitted by URI.
*
* @hide
*/
public URI toURILenient() throws URISyntaxException {
if (streamHandler == null) {
throw new IllegalStateException(protocol);
}
return new URI(streamHandler.toExternalForm(this, true));
}
/**
* Returns a string containing a concise, human-readable representation of
* this URL. The returned string is the same as the result of the method
* {@code toExternalForm()}.
*/
@Override public String toString() {
return toExternalForm();
}
/**
* Returns a string containing a concise, human-readable representation of
* this URL.
*/
public String toExternalForm() {
if (streamHandler == null) {
return "unknown protocol(" + protocol + ")://" + host + file;
}
return streamHandler.toExternalForm(this);
}
private void readObject(ObjectInputStream stream) throws IOException {
try {
stream.defaultReadObject();
if (host != null && authority == null) {
fixURL(true);
} else if (authority != null) {
int index;
if ((index = authority.lastIndexOf('@')) > -1) {
userInfo = authority.substring(0, index);
}
if (file != null && (index = file.indexOf('?')) > -1) {
query = file.substring(index + 1);
path = file.substring(0, index);
} else {
path = file;
}
}
setupStreamHandler();
if (streamHandler == null) {
throw new IOException("Unknown protocol: " + protocol);
}
hashCode = 0; // necessary until http://b/4471249 is fixed
} catch (ClassNotFoundException e) {
throw new IOException(e);
}
}
private void writeObject(ObjectOutputStream s) throws IOException {
s.defaultWriteObject();
}
/** @hide */
public int getEffectivePort() {
return URI.getEffectivePort(protocol, port);
}
/**
* Returns the protocol of this URL like "http" or "file". This is also
* known as the scheme. The returned string is lower case.
*/
public String getProtocol() {
return protocol;
}
/**
* Returns the authority part of this URL, or null if this URL has no
* authority.
*/
public String getAuthority() {
return authority;
}
/**
* Returns the user info of this URL, or null if this URL has no user info.
*/
public String getUserInfo() {
return userInfo;
}
/**
* Returns the host name or IP address of this URL.
*/
public String getHost() {
return host;
}
/**
* Returns the port number of this URL or {@code -1} if this URL has no
* explicit port.
*
* <p>If this URL has no explicit port, connections opened using this URL
* will use its {@link #getDefaultPort() default port}.
*/
public int getPort() {
return port;
}
/**
* Returns the default port number of the protocol used by this URL. If no
* default port is defined by the protocol or the {@code URLStreamHandler},
* {@code -1} will be returned.
*
* @see URLStreamHandler#getDefaultPort
*/
public int getDefaultPort() {
return streamHandler.getDefaultPort();
}
/**
* Returns the file of this URL.
*/
public String getFile() {
return file;
}
/**
* Returns the path part of this URL.
*/
public String getPath() {
return path;
}
/**
* Returns the query part of this URL, or null if this URL has no query.
*/
public String getQuery() {
return query;
}
/**
* Returns the value of the reference part of this URL, or null if this URL
* has no reference part. This is also known as the fragment.
*/
public String getRef() {
return ref;
}
/**
* Sets the properties of this URL using the provided arguments. Only a
* {@code URLStreamHandler} can use this method to set fields of the
* existing URL instance. A URL is generally constant.
*/
protected void set(String protocol, String host, int port, String authority, String userInfo,
String path, String query, String ref) {
String file = path;
if (query != null && !query.isEmpty()) {
file += "?" + query;
}
set(protocol, host, port, file, ref);
this.authority = authority;
this.userInfo = userInfo;
this.path = path;
this.query = query;
}
}
24的代碼如下：
/*
* Copyright (C) 2014 The Android Open Source Project
* Copyright (c) 1995, 2008, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.net;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Hashtable;
import java.util.StringTokenizer;
import sun.security.util.SecurityConstants;
/**
* Class <code>URL</code> represents a Uniform Resource
* Locator, a pointer to a "resource" on the World
* Wide Web. A resource can be something as simple as a file or a
* directory, or it can be a reference to a more complicated object,
* such as a query to a database or to a search engine. More
* information on the types of URLs and their formats can be found at:
* <blockquote>
* <a href="http://www.socs.uts.edu.au/MosaicDocs-old/url-primer.html">
* <i>http://www.socs.uts.edu.au/MosaicDocs-old/url-primer.html</i></a>
* </blockquote>
* <p>
* In general, a URL can be broken into several parts. The previous
* example of a URL indicates that the protocol to use is
* <code>http</code> (HyperText Transfer Protocol) and that the
* information resides on a host machine named
* <code>www.socs.uts.edu.au</code>. The information on that host
* machine is named <code>/MosaicDocs-old/url-primer.html</code>. The exact
* meaning of this name on the host machine is both protocol
* dependent and host dependent. The information normally resides in
* a file, but it could be generated on the fly. This component of
* the URL is called the <i>path</i> component.
* <p>
* A URL can optionally specify a "port", which is the
* port number to which the TCP connection is made on the remote host
* machine. If the port is not specified, the default port for
* the protocol is used instead. For example, the default port for
* <code>http</code> is <code>80</code>. An alternative port could be
* specified as:
* <blockquote><pre>
* http://www.socs.uts.edu.au:80/MosaicDocs-old/url-primer.html
* </pre></blockquote>
* <p>
* The syntax of <code>URL</code> is defined by <a
* href="http://www.ietf.org/rfc/rfc2396.txt"><i>RFC 2396: Uniform
* Resource Identifiers (URI): Generic Syntax</i></a>, amended by <a
* href="http://www.ietf.org/rfc/rfc2732.txt"><i>RFC 2732: Format for
* Literal IPv6 Addresses in URLs</i></a>. The Literal IPv6 address format
* also supports scope_ids. The syntax and usage of scope_ids is described
* <a href="Inet6Address.html#scoped">here</a>.
* <p>
* A URL may have appended to it a "fragment", also known
* as a "ref" or a "reference". The fragment is indicated by the sharp
* sign character "#" followed by more characters. For example,
* <blockquote><pre>
* http://java.sun.com/index.html#chapter1
* </pre></blockquote>
* <p>
* This fragment is not technically part of the URL. Rather, it
* indicates that after the specified resource is retrieved, the
* application is specifically interested in that part of the
* document that has the tag <code>chapter1</code> attached to it. The
* meaning of a tag is resource specific.
* <p>
* An application can also specify a "relative URL",
* which contains only enough information to reach the resource
* relative to another URL. Relative URLs are frequently used within
* HTML pages. For example, if the contents of the URL:
* <blockquote><pre>
* http://java.sun.com/index.html
* </pre></blockquote>
* contained within it the relative URL:
* <blockquote><pre>
* FAQ.html
* </pre></blockquote>
* it would be a shorthand for:
* <blockquote><pre>
* http://java.sun.com/FAQ.html
* </pre></blockquote>
* <p>
* The relative URL need not specify all the components of a URL. If
* the protocol, host name, or port number is missing, the value is
* inherited from the fully specified URL. The file component must be
* specified. The optional fragment is not inherited.
* <p>
* The URL class does not itself encode or decode any URL components
* according to the escaping mechanism defined in RFC2396. It is the
* responsibility of the caller to encode any fields, which need to be
* escaped prior to calling URL, and also to decode any escaped fields,
* that are returned from URL. Furthermore, because URL has no knowledge
* of URL escaping, it does not recognise equivalence between the encoded
* or decoded form of the same URL. For example, the two URLs:<br>
* <pre> http://foo.com/hello world/ and http://foo.com/hello%20world</pre>
* would be considered not equal to each other.
* <p>
* Note, the {@link java.net.URI} class does perform escaping of its
* component fields in certain circumstances. The recommended way
* to manage the encoding and decoding of URLs is to use {@link java.net.URI},
* and to convert between these two classes using {@link #toURI()} and
* {@link URI#toURL()}.
* <p>
* The {@link URLEncoder} and {@link URLDecoder} classes can also be
* used, but only for HTML form encoding, which is not the same
* as the encoding scheme defined in RFC2396.
*
* @author James Gosling
* @since JDK1.0
*/
public final class URL implements java.io.Serializable {
static final long serialVersionUID = -7627629688361524110L;
/**
* The property which specifies the package prefix list to be scanned
* for protocol handlers. The value of this property (if any) should
* be a vertical bar delimited list of package names to search through
* for a protocol handler to load. The policy of this class is that
* all protocol handlers will be in a class called <protocolname>.Handler,
* and each package in the list is examined in turn for a matching
* handler. If none are found (or the property is not specified), the
* default package prefix, sun.net.www.protocol, is used. The search
* proceeds from the first package in the list to the last and stops
* when a match is found.
*/
private static final String protocolPathProp = "java.protocol.handler.pkgs";
/**
* The protocol to use (ftp, http, nntp, ... etc.) .
* @serial
*/
private String protocol;
/**
* The host name to connect to.
* @serial
*/
private String host;
/**
* The protocol port to connect to.
* @serial
*/
private int port = -1;
/**
* The specified file name on that host. <code>file</code> is
* defined as <code>path[?query]</code>
* @serial
*/
private String file;
/**
* The query part of this URL.
*/
private transient String query;
/**
* The authority part of this URL.
* @serial
*/
private String authority;
/**
* The path part of this URL.
*/
private transient String path;
/**
* The userinfo part of this URL.
*/
private transient String userInfo;
/**
* # reference.
* @serial
*/
private String ref;
/**
* The host's IP address, used in equals and hashCode.
* Computed on demand. An uninitialized or unknown hostAddress is null.
*/
transient InetAddress hostAddress;
/**
* The URLStreamHandler for this URL.
*/
transient URLStreamHandler handler;
/* Our hash code.
* @serial
*/
// ----- BEGIN android -----
//private int hashCode = -1;
private transient int hashCode = -1;
// ----- END android -----
/**
* Creates a <code>URL</code> object from the specified
* <code>protocol</code>, <code>host</code>, <code>port</code>
* number, and <code>file</code>.<p>
*
* <code>host</code> can be expressed as a host name or a literal
* IP address. If IPv6 literal address is used, it should be
* enclosed in square brackets (<tt>'['</tt> and <tt>']'</tt>), as
* specified by <a
* href="http://www.ietf.org/rfc/rfc2732.txt">RFC 2732</a>;
* However, the literal IPv6 address format defined in <a
* href="http://www.ietf.org/rfc/rfc2373.txt"><i>RFC 2373: IP
* Version 6 Addressing Architecture</i></a> is also accepted.<p>
*
* Specifying a <code>port</code> number of <code>-1</code>
* indicates that the URL should use the default port for the
* protocol.<p>
*
* If this is the first URL object being created with the specified
* protocol, a <i>stream protocol handler</i> object, an instance of
* class <code>URLStreamHandler</code>, is created for that protocol:
* <ol>
* <li>If the application has previously set up an instance of
* <code>URLStreamHandlerFactory</code> as the stream handler factory,
* then the <code>createURLStreamHandler</code> method of that instance
* is called with the protocol string as an argument to create the
* stream protocol handler.
* <li>If no <code>URLStreamHandlerFactory</code> has yet been set up,
* or if the factory's <code>createURLStreamHandler</code> method
* returns <code>null</code>, then the constructor finds the
* value of the system property:
* <blockquote><pre>
* java.protocol.handler.pkgs
* </pre></blockquote>
* If the value of that system property is not <code>null</code>,
* it is interpreted as a list of packages separated by a vertical
* slash character '<code>|</code>'. The constructor tries to load
* the class named:
* <blockquote><pre>
* <<i>package</i>>.<<i>protocol</i>>.Handler
* </pre></blockquote>
* where <<i>package</i>> is replaced by the name of the package
* and <<i>protocol</i>> is replaced by the name of the protocol.
* If this class does not exist, or if the class exists but it is not
* a subclass of <code>URLStreamHandler</code>, then the next package
* in the list is tried.
* <li>If the previous step fails to find a protocol handler, then the
* constructor tries to load from a system default package.
* <blockquote><pre>
* <<i>system default package</i>>.<<i>protocol</i>>.Handler
* </pre></blockquote>
* If this class does not exist, or if the class exists but it is not a
* subclass of <code>URLStreamHandler</code>, then a
* <code>MalformedURLException</code> is thrown.
* </ol>
*
* <p>Protocol handlers for the following protocols are guaranteed
* to exist on the search path :-
* <blockquote><pre>
* http, https, ftp, file, and jar
* </pre></blockquote>
* Protocol handlers for additional protocols may also be
* available.
*
* <p>No validation of the inputs is performed by this constructor.
*
* @param protocol the name of the protocol to use.
* @param host the name of the host.
* @param port the port number on the host.
* @param file the file on the host
* @exception MalformedURLException if an unknown protocol is specified.
* @see java.lang.System#getProperty(java.lang.String)
* @see java.net.URL#setURLStreamHandlerFactory(
* java.net.URLStreamHandlerFactory)
* @see java.net.URLStreamHandler
* @see java.net.URLStreamHandlerFactory#createURLStreamHandler(
* java.lang.String)
*/
public URL(String protocol, String host, int port, String file)
throws MalformedURLException
{
this(protocol, host, port, file, null);
}
/**
* Creates a URL from the specified <code>protocol</code>
* name, <code>host</code> name, and <code>file</code> name. The
* default port for the specified protocol is used.
* <p>
* This method is equivalent to calling the four-argument
* constructor with the arguments being <code>protocol</code>,
* <code>host</code>, <code>-1</code>, and <code>file</code>.
*
* No validation of the inputs is performed by this constructor.
*
* @param protocol the name of the protocol to use.
* @param host the name of the host.
* @param file the file on the host.
* @exception MalformedURLException if an unknown protocol is specified.
* @see java.net.URL#URL(java.lang.String, java.lang.String,
* int, java.lang.String)
*/
public URL(String protocol, String host, String file)
throws MalformedURLException {
this(protocol, host, -1, file);
}
/**
* Creates a <code>URL</code> object from the specified
* <code>protocol</code>, <code>host</code>, <code>port</code>
* number, <code>file</code>, and <code>handler</code>. Specifying
* a <code>port</code> number of <code>-1</code> indicates that
* the URL should use the default port for the protocol. Specifying
* a <code>handler</code> of <code>null</code> indicates that the URL
* should use a default stream handler for the protocol, as outlined
* for:
* java.net.URL#URL(java.lang.String, java.lang.String, int,
* java.lang.String)
*
* <p>If the handler is not null and there is a security manager,
* the security manager's <code>checkPermission</code>
* method is called with a
* <code>NetPermission("specifyStreamHandler")</code> permission.
* This may result in a SecurityException.
*
* No validation of the inputs is performed by this constructor.
*
* @param protocol the name of the protocol to use.
* @param host the name of the host.
* @param port the port number on the host.
* @param file the file on the host
* @param handler the stream handler for the URL.
* @exception MalformedURLException if an unknown protocol is specified.
* @exception SecurityException
* if a security manager exists and its
* <code>checkPermission</code> method doesn't allow
* specifying a stream handler explicitly.
* @see java.lang.System#getProperty(java.lang.String)
* @see java.net.URL#setURLStreamHandlerFactory(
* java.net.URLStreamHandlerFactory)
* @see java.net.URLStreamHandler
* @see java.net.URLStreamHandlerFactory#createURLStreamHandler(
* java.lang.String)
* @see SecurityManager#checkPermission
* @see java.net.NetPermission
*/
public URL(String protocol, String host, int port, String file,
URLStreamHandler handler) throws MalformedURLException {
if (handler != null) {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
// check for permission to specify a handler
checkSpecifyHandler(sm);
}
}
protocol = protocol.toLowerCase();
this.protocol = protocol;
if (host != null) {
/**
* if host is a literal IPv6 address,
* we will make it conform to RFC 2732
*/
if (host.indexOf(':') >= 0 && !host.startsWith("[")) {
host = "["+host+"]";
}
this.host = host;
if (port < -1) {
throw new MalformedURLException("Invalid port number :" +
port);
}
this.port = port;
authority = (port == -1) ? host : host + ":" + port;
}
Parts parts = new Parts(file, host);
path = parts.getPath();
query = parts.getQuery();
if (query != null) {
this.file = path + "?" + query;
} else {
this.file = path;
}
ref = parts.getRef();
// Note: we don't do validation of the URL here. Too risky to change
// right now, but worth considering for future reference. -br
if (handler == null &&
(handler = getURLStreamHandler(protocol)) == null) {
throw new MalformedURLException("unknown protocol: " + protocol);
}
this.handler = handler;
}
/**
* Creates a <code>URL</code> object from the <code>String</code>
* representation.
* <p>
* This constructor is equivalent to a call to the two-argument
* constructor with a <code>null</code> first argument.
*
* @param spec the <code>String</code> to parse as a URL.
* @exception MalformedURLException if no protocol is specified, or an
* unknown protocol is found, or <tt>spec</tt> is <tt>null</tt>.
* @see java.net.URL#URL(java.net.URL, java.lang.String)
*/
public URL(String spec) throws MalformedURLException {
this(null, spec);
}
/**
* Creates a URL by parsing the given spec within a specified context.
*
* The new URL is created from the given context URL and the spec
* argument as described in
* RFC2396 "Uniform Resource Identifiers : Generic * Syntax" :
* <blockquote><pre>
* <scheme>://<authority><path>?<query>#<fragment>
* </pre></blockquote>
* The reference is parsed into the scheme, authority, path, query and
* fragment parts. If the path component is empty and the scheme,
* authority, and query components are undefined, then the new URL is a
* reference to the current document. Otherwise, the fragment and query
* parts present in the spec are used in the new URL.
* <p>
* If the scheme component is defined in the given spec and does not match
* the scheme of the context, then the new URL is created as an absolute
* URL based on the spec alone. Otherwise the scheme component is inherited
* from the context URL.
* <p>
* If the authority component is present in the spec then the spec is
* treated as absolute and the spec authority and path will replace the
* context authority and path. If the authority component is absent in the
* spec then the authority of the new URL will be inherited from the
* context.
* <p>
* If the spec's path component begins with a slash character
* "/" then the
* path is treated as absolute and the spec path replaces the context path.
* <p>
* Otherwise, the path is treated as a relative path and is appended to the
* context path, as described in RFC2396. Also, in this case,
* the path is canonicalized through the removal of directory
* changes made by occurences of ".." and ".".
* <p>
* For a more detailed description of URL parsing, refer to RFC2396.
*
* @param context the context in which to parse the specification.
* @param spec the <code>String</code> to parse as a URL.
* @exception MalformedURLException if no protocol is specified, or an
* unknown protocol is found, or <tt>spec</tt> is <tt>null</tt>.
* @see java.net.URL#URL(java.lang.String, java.lang.String,
* int, java.lang.String)
* @see java.net.URLStreamHandler
* @see java.net.URLStreamHandler#parseURL(java.net.URL,
* java.lang.String, int, int)
*/
public URL(URL context, String spec) throws MalformedURLException {
this(context, spec, null);
}
/**
* Creates a URL by parsing the given spec with the specified handler
* within a specified context. If the handler is null, the parsing
* occurs as with the two argument constructor.
*
* @param context the context in which to parse the specification.
* @param spec the <code>String</code> to parse as a URL.
* @param handler the stream handler for the URL.
* @exception MalformedURLException if no protocol is specified, or an
* unknown protocol is found, or <tt>spec</tt> is <tt>null</tt>.
* @exception SecurityException
* if a security manager exists and its
* <code>checkPermission</code> method doesn't allow
* specifying a stream handler.
* @see java.net.URL#URL(java.lang.String, java.lang.String,
* int, java.lang.String)
* @see java.net.URLStreamHandler
* @see java.net.URLStreamHandler#parseURL(java.net.URL,
* java.lang.String, int, int)
*/
public URL(URL context, String spec, URLStreamHandler handler)
throws MalformedURLException
{
String original = spec;
int i, limit, c;
int start = 0;
String newProtocol = null;
boolean aRef=false;
boolean isRelative = false;
// Check for permission to specify a handler
if (handler != null) {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
checkSpecifyHandler(sm);
}
}
try {
limit = spec.length();
while ((limit > 0) && (spec.charAt(limit - 1) <= ' ')) {
limit--; //eliminate trailing whitespace
}
while ((start < limit) && (spec.charAt(start) <= ' ')) {
start++; // eliminate leading whitespace
}
if (spec.regionMatches(true, start, "url:", 0, 4)) {
start += 4;
}
if (start < spec.length() && spec.charAt(start) == '#') {
/* we're assuming this is a ref relative to the context URL.
* This means protocols cannot start w/ '#', but we must parse
* ref URL's like: "hello:there" w/ a ':' in them.
*/
aRef=true;
}
for (i = start ; !aRef && (i < limit) &&
((c = spec.charAt(i)) != '/') ; i++) {
if (c == ':') {
String s = spec.substring(start, i).toLowerCase();
if (isValidProtocol(s)) {
newProtocol = s;
start = i + 1;
}
break;
}
}
// Only use our context if the protocols match.
protocol = newProtocol;
if ((context != null) && ((newProtocol == null) ||
newProtocol.equalsIgnoreCase(context.protocol))) {
// inherit the protocol handler from the context
// if not specified to the constructor
if (handler == null) {
handler = context.handler;
}
// If the context is a hierarchical URL scheme and the spec
// contains a matching scheme then maintain backwards
// compatibility and treat it as if the spec didn't contain
// the scheme; see 5.2.3 of RFC2396
if (context.path != null && context.path.startsWith("/"))
newProtocol = null;
if (newProtocol == null) {
protocol = context.protocol;
authority = context.authority;
userInfo = context.userInfo;
host = context.host;
port = context.port;
file = context.file;
path = context.path;
isRelative = true;
}
}
if (protocol == null) {
throw new MalformedURLException("no protocol: "+original);
}
// Get the protocol handler if not specified or the protocol
// of the context could not be used
if (handler == null &&
(handler = getURLStreamHandler(protocol)) == null) {
throw new MalformedURLException("unknown protocol: "+protocol);
}
this.handler = handler;
i = spec.indexOf('#', start);
if (i >= 0) {
ref = spec.substring(i + 1, limit);
limit = i;
}
/*
* Handle special case inheritance of query and fragment
* implied by RFC2396 section 5.2.2.
*/
if (isRelative && start == limit) {
query = context.query;
if (ref == null) {
ref = context.ref;
}
}
handler.parseURL(this, spec, start, limit);
} catch(MalformedURLException e) {
throw e;
} catch(Exception e) {
MalformedURLException exception = new MalformedURLException(e.getMessage());
exception.initCause(e);
throw exception;
}
}
/*
* Returns true if specified string is a valid protocol name.
*/
private boolean isValidProtocol(String protocol) {
int len = protocol.length();
if (len < 1)
return false;
char c = protocol.charAt(0);
if (!Character.isLetter(c))
return false;
for (int i = 1; i < len; i++) {
c = protocol.charAt(i);
if (!Character.isLetterOrDigit(c) && c != '.' && c != '+' &&
c != '-') {
return false;
}
}
return true;
}
/*
* Checks for permission to specify a stream handler.
*/
private void checkSpecifyHandler(SecurityManager sm) {
sm.checkPermission(SecurityConstants.SPECIFY_HANDLER_PERMISSION);
}
/**
* Sets the fields of the URL. This is not a public method so that
* only URLStreamHandlers can modify URL fields. URLs are
* otherwise constant.
*
* @param protocol the name of the protocol to use
* @param host the name of the host
@param port the port number on the host
* @param file the file on the host
* @param ref the internal reference in the URL
*/
protected void set(String protocol, String host,
int port, String file, String ref) {
synchronized (this) {
this.protocol = protocol;
this.host = host;
authority = port == -1 ? host : host + ":" + port;
this.port = port;
this.file = file;
this.ref = ref;
/* This is very important. We must recompute this after the
* URL has been changed. */
hashCode = -1;
hostAddress = null;
int q = file.lastIndexOf('?');
if (q != -1) {
query = file.substring(q+1);
path = file.substring(0, q);
} else
path = file;
}
}
/**
* Sets the specified 8 fields of the URL. This is not a public method so
* that only URLStreamHandlers can modify URL fields. URLs are otherwise
* constant.
*
* @param protocol the name of the protocol to use
* @param host the name of the host
* @param port the port number on the host
* @param authority the authority part for the url
* @param userInfo the username and password
* @param path the file on the host
* @param ref the internal reference in the URL
* @param query the query part of this URL
* @since 1.3
*/
protected void set(String protocol, String host, int port,
String authority, String userInfo, String path,
String query, String ref) {
synchronized (this) {
this.protocol = protocol;
this.host = host;
this.port = port;
this.file = (query == null || query.isEmpty()) ? path : path + "?" + query;
this.userInfo = userInfo;
this.path = path;
this.ref = ref;
/* This is very important. We must recompute this after the
* URL has been changed. */
hashCode = -1;
hostAddress = null;
this.query = query;
this.authority = authority;
}
}
/**
* Gets the query part of this <code>URL</code>.
*
* @return the query part of this <code>URL</code>,
* or <CODE>null</CODE> if one does not exist
* @since 1.3
*/
public String getQuery() {
return query;
}
/**
* Gets the path part of this <code>URL</code>.
*
* @return the path part of this <code>URL</code>, or an
* empty string if one does not exist
* @since 1.3
*/
public String getPath() {
return path;
}
/**
* Gets the userInfo part of this <code>URL</code>.
*
* @return the userInfo part of this <code>URL</code>, or
* <CODE>null</CODE> if one does not exist
* @since 1.3
*/
public String getUserInfo() {
return userInfo;
}
/**
* Gets the authority part of this <code>URL</code>.
*
* @return the authority part of this <code>URL</code>
* @since 1.3
*/
public String getAuthority() {
return authority;
}
/**
* Gets the port number of this <code>URL</code>.
*
* @return the port number, or -1 if the port is not set
*/
public int getPort() {
return port;
}
/**
* Gets the default port number of the protocol associated
* with this <code>URL</code>. If the URL scheme or the URLStreamHandler
* for the URL do not define a default port number,
* then -1 is returned.
*
* @return the port number
* @since 1.4
*/
public int getDefaultPort() {
return handler.getDefaultPort();
}
/**
* Gets the protocol name of this <code>URL</code>.
*
* @return the protocol of this <code>URL</code>.
*/
public String getProtocol() {
return protocol;
}
/**
* Gets the host name of this <code>URL</code>, if applicable.
* The format of the host conforms to RFC 2732, i.e. for a
* literal IPv6 address, this method will return the IPv6 address
* enclosed in square brackets (<tt>'['</tt> and <tt>']'</tt>).
*
* @return the host name of this <code>URL</code>.
*/
public String getHost() {
return host;
}
/**
* Gets the file name of this <code>URL</code>.
* The returned file portion will be
* the same as <CODE>getPath()</CODE>, plus the concatenation of
* the value of <CODE>getQuery()</CODE>, if any. If there is
* no query portion, this method and <CODE>getPath()</CODE> will
* return identical results.
*
* @return the file name of this <code>URL</code>,
* or an empty string if one does not exist
*/
public String getFile() {
return file;
}
/**
* Gets the anchor (also known as the "reference") of this
* <code>URL</code>.
*
* @return the anchor (also known as the "reference") of this
* <code>URL</code>, or <CODE>null</CODE> if one does not exist
*/
public String getRef() {
return ref;
}
/**
* Compares this URL for equality with another object.<p>
*
* If the given object is not a URL then this method immediately returns
* <code>false</code>.<p>
*
* Two URL objects are equal if they have the same protocol, reference
* equivalent hosts, have the same port number on the host, and the same
* file and fragment of the file.<p>
*
* Returns true if this URL equals {@code o}. URLs are equal if they have
* the same protocol, host, port, file, and reference.
*
* <h3>Network I/O Warning</h3>
* <p>Some implementations of URL.equals() resolve host names over the
* network. This is problematic:
* <ul>
* <li><strong>The network may be slow.</strong> Many classes, including
* core collections like {@link java.util.Map Map} and {@link java.util.Set
* Set} expect that {@code equals} and {@code hashCode} will return quickly.
* By violating this assumption, this method posed potential performance
* problems.
* <li><strong>Equal IP addresses do not imply equal content.</strong>
* Virtual hosting permits unrelated sites to share an IP address. This
* method could report two otherwise unrelated URLs to be equal because
* they're hosted on the same server.</li>
* <li><strong>The network may not be available.</strong> Two URLs could be
* equal when a network is available and unequal otherwise.</li>
* <li><strong>The network may change.</strong> The IP address for a given
* host name varies by network and over time. This is problematic for mobile
* devices. Two URLs could be equal on some networks and unequal on
* others.</li>
* </ul>
* <p>This problem is fixed in Android 4.0 (Ice Cream Sandwich). In that
* release, URLs are only equal if their host names are equal (ignoring
* case).
*
* @param obj the URL to compare against.
* @return <code>true</code> if the objects are the same;
* <code>false</code> otherwise.
*/
public boolean equals(Object obj) {
if (!(obj instanceof URL))
return false;
URL u2 = (URL)obj;
return handler.equals(this, u2);
}
/**
* Creates an integer suitable for hash table indexing.<p>
*
* The hash code is based upon all the URL components relevant for URL
* comparison. As such, this operation is a blocking operation.<p>
*
* @return a hash code for this <code>URL</code>.
*/
public synchronized int hashCode() {
if (hashCode != -1)
return hashCode;
hashCode = handler.hashCode(this);
return hashCode;
}
/**
* Compares two URLs, excluding the fragment component.<p>
*
* Returns <code>true</code> if this <code>URL</code> and the
* <code>other</code> argument are equal without taking the
* fragment component into consideration.
*
* @param other the <code>URL</code> to compare against.
* @return <code>true</code> if they reference the same remote object;
* <code>false</code> otherwise.
*/
public boolean sameFile(URL other) {
return handler.sameFile(this, other);
}
/**
* Constructs a string representation of this <code>URL</code>. The
* string is created by calling the <code>toExternalForm</code>
* method of the stream protocol handler for this object.
*
* @return a string representation of this object.
* @see java.net.URL#URL(java.lang.String, java.lang.String, int,
* java.lang.String)
* @see java.net.URLStreamHandler#toExternalForm(java.net.URL)
*/
public String toString() {
return toExternalForm();
}
/**
* Constructs a string representation of this <code>URL</code>. The
* string is created by calling the <code>toExternalForm</code>
* method of the stream protocol handler for this object.
*
* @return a string representation of this object.
* @see java.net.URL#URL(java.lang.String, java.lang.String,
* int, java.lang.String)
* @see java.net.URLStreamHandler#toExternalForm(java.net.URL)
*/
public String toExternalForm() {
return handler.toExternalForm(this);
}
/**
* Returns a {@link java.net.URI} equivalent to this URL.
* This method functions in the same way as <code>new URI (this.toString())</code>.
* <p>Note, any URL instance that complies with RFC 2396 can be converted
* to a URI. However, some URLs that are not strictly in compliance
* can not be converted to a URI.
*
* @exception URISyntaxException if this URL is not formatted strictly according to
* to RFC2396 and cannot be converted to a URI.
*
* @return a URI instance equivalent to this URL.
* @since 1.5
*/
public URI toURI() throws URISyntaxException {
return new URI (toString());
}
/**
* Returns a {@link java.net.URLConnection URLConnection} instance that
* represents a connection to the remote object referred to by the
* {@code URL}.
*
* <P>A new instance of {@linkplain java.net.URLConnection URLConnection} is
* created every time when invoking the
* {@linkplain java.net.URLStreamHandler#openConnection(URL)
* URLStreamHandler.openConnection(URL)} method of the protocol handler for
* this URL.</P>
*
* <P>It should be noted that a URLConnection instance does not establish
* the actual network connection on creation. This will happen only when
* calling {@linkplain java.net.URLConnection#connect() URLConnection.connect()}.</P>
*
* <P>If for the URL's protocol (such as HTTP or JAR), there
* exists a public, specialized URLConnection subclass belonging
* to one of the following packages or one of their subpackages:
* java.lang, java.io, java.util, java.net, the connection
* returned will be of that subclass. For example, for HTTP an
* HttpURLConnection will be returned, and for JAR a
* JarURLConnection will be returned.</P>
*
* @return a {@link java.net.URLConnection URLConnection} linking
* to the URL.
* @exception IOException if an I/O exception occurs.
* @see java.net.URL#URL(java.lang.String, java.lang.String,
* int, java.lang.String)
*/
public URLConnection openConnection() throws java.io.IOException {
return handler.openConnection(this);
}
/**
* Same as {@link #openConnection()}, except that the connection will be
* made through the specified proxy; Protocol handlers that do not
* support proxing will ignore the proxy parameter and make a
* normal connection.
*
* Invoking this method preempts the system's default ProxySelector
* settings.
*
* @param proxy the Proxy through which this connection
* will be made. If direct connection is desired,
* Proxy.NO_PROXY should be specified.
* @return a <code>URLConnection</code> to the URL.
* @exception IOException if an I/O exception occurs.
* @exception SecurityException if a security manager is present
* and the caller doesn't have permission to connect
* to the proxy.
* @exception IllegalArgumentException will be thrown if proxy is null,
* or proxy has the wrong type
* @exception UnsupportedOperationException if the subclass that
* implements the protocol handler doesn't support
* this method.
* @see java.net.URL#URL(java.lang.String, java.lang.String,
* int, java.lang.String)
* @see java.net.URLConnection
* @see java.net.URLStreamHandler#openConnection(java.net.URL,
* java.net.Proxy)
* @since 1.5
*/
public URLConnection openConnection(Proxy proxy)
throws java.io.IOException {
if (proxy == null) {
throw new IllegalArgumentException("proxy can not be null");
}
// Create a copy of Proxy as a security measure
Proxy p = proxy == Proxy.NO_PROXY ? Proxy.NO_PROXY : sun.net.ApplicationProxy.create(proxy);
SecurityManager sm = System.getSecurityManager();
if (p.type() != Proxy.Type.DIRECT && sm != null) {
InetSocketAddress epoint = (InetSocketAddress) p.address();
if (epoint.isUnresolved())
sm.checkConnect(epoint.getHostName(), epoint.getPort());
else
sm.checkConnect(epoint.getAddress().getHostAddress(),
epoint.getPort());
}
return handler.openConnection(this, p);
}
/**
* Opens a connection to this <code>URL</code> and returns an
* <code>InputStream</code> for reading from that connection. This
* method is a shorthand for:
* <blockquote><pre>
* openConnection().getInputStream()
* </pre></blockquote>
*
* @return an input stream for reading from the URL connection.
* @exception IOException if an I/O exception occurs.
* @see java.net.URL#openConnection()
* @see java.net.URLConnection#getInputStream()
*/
public final InputStream openStream() throws java.io.IOException {
return openConnection().getInputStream();
}
/**
* Gets the contents of this URL. This method is a shorthand for:
* <blockquote><pre>
* openConnection().getContent()
* </pre></blockquote>
*
* @return the contents of this URL.
* @exception IOException if an I/O exception occurs.
* @see java.net.URLConnection#getContent()
*/
public final Object getContent() throws java.io.IOException {
return openConnection().getContent();
}
/**
* Gets the contents of this URL. This method is a shorthand for:
* <blockquote><pre>
* openConnection().getContent(Class[])
* </pre></blockquote>
*
* @param classes an array of Java types
* @return the content object of this URL that is the first match of
* the types specified in the classes array.
* null if none of the requested types are supported.
* @exception IOException if an I/O exception occurs.
* @see java.net.URLConnection#getContent(Class[])
* @since 1.3
*/
public final Object getContent(Class[] classes)
throws java.io.IOException {
return openConnection().getContent(classes);
}
/**
* The URLStreamHandler factory.
*/
static URLStreamHandlerFactory factory;
/**
* Sets an application's <code>URLStreamHandlerFactory</code>.
* This method can be called at most once in a given Java Virtual
* Machine.
*
*<p> The <code>URLStreamHandlerFactory</code> instance is used to
*construct a stream protocol handler from a protocol name.
*
* <p> If there is a security manager, this method first calls
* the security manager's <code>checkSetFactory</code> method
* to ensure the operation is allowed.
* This could result in a SecurityException.
*
* @param fac the desired factory.
* @exception Error if the application has already set a factory.
* @exception SecurityException if a security manager exists and its
* <code>checkSetFactory</code> method doesn't allow
* the operation.
* @see java.net.URL#URL(java.lang.String, java.lang.String,
* int, java.lang.String)
* @see java.net.URLStreamHandlerFactory
* @see SecurityManager#checkSetFactory
*/
public static void setURLStreamHandlerFactory(URLStreamHandlerFactory fac) {
synchronized (streamHandlerLock) {
if (factory != null) {
throw new Error("factory already defined");
}
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkSetFactory();
}
handlers.clear();
factory = fac;
}
}
/**
* A table of protocol handlers.
*/
static Hashtable handlers = new Hashtable();
private static Object streamHandlerLock = new Object();
/**
* Returns the Stream Handler.
* @param protocol the protocol to use
*/
static URLStreamHandler getURLStreamHandler(String protocol) {
URLStreamHandler handler = (URLStreamHandler)handlers.get(protocol);
if (handler == null) {
boolean checkedWithFactory = false;
// Use the factory (if any)
if (factory != null) {
handler = factory.createURLStreamHandler(protocol);
checkedWithFactory = true;
}
// Try java protocol handler
if (handler == null) {
final String packagePrefixList = System.getProperty(protocolPathProp,"");
StringTokenizer packagePrefixIter = new StringTokenizer(packagePrefixList, "|");
while (handler == null &&
packagePrefixIter.hasMoreTokens()) {
String packagePrefix = packagePrefixIter.nextToken().trim();
try {
String clsName = packagePrefix + "." + protocol + ".Handler";
Class cls = null;
try {
ClassLoader cl = ClassLoader.getSystemClassLoader();
cls = Class.forName(clsName, true, cl);
} catch (ClassNotFoundException e) {
ClassLoader contextLoader = Thread.currentThread().getContextClassLoader();
if (contextLoader != null) {
cls = Class.forName(clsName, true, contextLoader);
}
}
if (cls != null) {
handler =
(URLStreamHandler)cls.newInstance();
}
} catch (ReflectiveOperationException ignored) {
}
}
}
// Fallback to built-in stream handler.
// Makes okhttp the default http/https handler
if (handler == null) {
try {
if (protocol.equals("file")) {
handler = (URLStreamHandler)Class.
forName("sun.net.www.protocol.file.Handler").newInstance();
} else if (protocol.equals("ftp")) {
handler = (URLStreamHandler)Class.
forName("sun.net.www.protocol.ftp.Handler").newInstance();
} else if (protocol.equals("jar")) {
handler = (URLStreamHandler)Class.
forName("sun.net.www.protocol.jar.Handler").newInstance();
} else if (protocol.equals("http")) {
handler = (URLStreamHandler)Class.
forName("com.android.okhttp.HttpHandler").newInstance();
} else if (protocol.equals("https")) {
handler = (URLStreamHandler)Class.
forName("com.android.okhttp.HttpsHandler").newInstance();
}
} catch (Exception e) {
throw new AssertionError(e);
}
}
synchronized (streamHandlerLock) {
URLStreamHandler handler2 = null;
// Check again with hashtable just in case another
// thread created a handler since we last checked
handler2 = (URLStreamHandler)handlers.get(protocol);
if (handler2 != null) {
return handler2;
}
// Check with factory if another thread set a
// factory since our last check
if (!checkedWithFactory && factory != null) {
handler2 = factory.createURLStreamHandler(protocol);
}
if (handler2 != null) {
// The handler from the factory must be given more
// importance. Discard the default handler that
// this thread created.
handler = handler2;
}
// Insert this handler into the hashtable
if (handler != null) {
handlers.put(protocol, handler);
}
}
}
return handler;
}
/**
* WriteObject is called to save the state of the URL to an
* ObjectOutputStream. The handler is not saved since it is
* specific to this system.
*
* @serialData the default write object value. When read back in,
* the reader must ensure that calling getURLStreamHandler with
* the protocol variable returns a valid URLStreamHandler and
* throw an IOException if it does not.
*/
private synchronized void writeObject(java.io.ObjectOutputStream s)
throws IOException
{
s.defaultWriteObject(); // write the fields
}
/**
* readObject is called to restore the state of the URL from the
* stream. It reads the components of the URL and finds the local
* stream handler.
*/
private synchronized void readObject(java.io.ObjectInputStream s)
throws IOException, ClassNotFoundException
{
s.defaultReadObject(); // read the fields
if ((handler = getURLStreamHandler(protocol)) == null) {
throw new IOException("unknown protocol: " + protocol);
}
// Construct authority part
if (authority == null &&
((host != null && host.length() > 0) || port != -1)) {
if (host == null)
host = "";
authority = (port == -1) ? host : host + ":" + port;
// Handle hosts with userInfo in them
int at = host.lastIndexOf('@');
if (at != -1) {
userInfo = host.substring(0, at);
host = host.substring(at+1);
}
} else if (authority != null) {
// Construct user info part
int ind = authority.indexOf('@');
if (ind != -1)
userInfo = authority.substring(0, ind);
}
// Construct path and query part
path = null;
query = null;
if (file != null) {
// Fix: only do this if hierarchical?
int q = file.lastIndexOf('?');
if (q != -1) {
query = file.substring(q+1);
path = file.substring(0, q);
} else
path = file;
}
hashCode = -1;
}
}
class Parts {
String path, query, ref;
Parts(String file, String host) {
int ind = file.indexOf('#');
ref = ind < 0 ? null: file.substring(ind + 1);
file = ind < 0 ? file: file.substring(0, ind);
int q = file.lastIndexOf('?');
if (q != -1) {
query = file.substring(q+1);
path = file.substring(0, q);
} else {
path = file;
}
if (path != null && path.length() > 0 && path.charAt(0) != '/' &&
host != null && !host.isEmpty()) {
path = '/' + path;
}
}
String getPath() {
return path;
}
String getQuery() {
return query;
}
String getRef() {
return ref;
}
}