JDK6的新特性
JDK6的新特性之一_Desktop類和SystemTray類
JDK6的新特性之七_用Console開發控制檯程序
JDK6的新特性之三_理解StAX
JDK6的新特性之九_CommonAnnotations
JDK6的新特性之二_使用JAXB2來實現對象與XML之間的映射
JDK6的新特性之五_輕量級HttpServer
JDK6的新特性之八_嵌入式數據庫Derby
JDK6的新特性之六_插入式註解處理API
JDK6的新特性之十_Web服務元數據
JDK6的新特性之十一_更簡單強大的JAX-WS
JDK6的新特性之十三_JTable的排序和過濾
JDK6的新特性之十二_腳本語言支持
JDK6的新特性之四_使用Compiler API
JDK6的新特性之一_Desktop類和SystemTray類
JDK6.0發佈有段時間了，新的JDK也有不少新的特性，我去網上搜集了一下，列在下面和大家一起學習．
１．Desktop和SystemTray. 在JDK6中 ,AWT新增加了兩個類:Desktop和SystemTray,前者可以用來打開系統默認瀏覽器瀏覽指定的URL,打開系統默認郵件客戶端給指定的郵箱發郵件,用默認應用程序打開或編輯文件(比如,用記事本打開以txt爲後綴名的文件),用系統默認的打印機打印文檔;後者可以用來在系統托盤區創建一個托盤程序。
我隨便找了幾張圖，在Tray裏面都是空的，沒有圖,可能是圖太大，有xdjm知道希望告訴我．
Java代碼
import java.awt.AWTException;
import java.awt.Desktop;
import java.awt.Image;
import java.awt.MenuItem;
import java.awt.PopupMenu;
import java.awt.SystemTray;
import java.awt.Toolkit;
import java.awt.TrayIcon;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
public class DesktopTrayTest{
private static Desktop desktop;
private static SystemTray st;
private static PopupMenu pm;
public static void main( String[] args ) {
if( Desktop.isDesktopSupported() ) {
desktop = Desktop.getDesktop();
}
if( SystemTray.isSupported() ) {
st = SystemTray.getSystemTray();
Image image = Toolkit.getDefaultToolkit().createImage( "http://www.51ppt.com.cn/Article/Uploadphotos/200604/20064147333288.png" );
createPopupMenu();
TrayIcon ti = new TrayIcon( image, "Demo", pm );
try{
st.add( ti );
} catch( AWTException awte ) {
awte.printStackTrace();
}
}
}
public static void sendMail( String mail ) {
if( desktop != null &&
desktop.isSupported( Desktop.Action.MAIL ) ) {
try {
desktop.mail( new URI( mail ) );
} catch (IOException e) {
e.printStackTrace();
} catch (URISyntaxException e) {
e.printStackTrace();
}
}
}
public static void openBrowser( String url ) {
if( desktop != null &&
desktop.isSupported( Desktop.Action.BROWSE )) {
try {
desktop.browse( new URI( url ) );
} catch (IOException e) {
e.printStackTrace();
} catch (URISyntaxException e) {
e.printStackTrace();
}
}
}
public static void edit() {
if( desktop != null &&
desktop.isSupported( Desktop.Action.EDIT ) ) {
File file = new File( "test.txt" );
try {
if( file.exists() == false ) {
file.create();
}
desktop.edit( file );
} catch( IOException ioe ) {
ioe.printStackTrace();
}
}
}
public static void createPopupMenu() {
pm = new PopupMenu();
MenuItem ob = new MenuItem( "Open url" );
ob.addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent ae ) {
openBrowser( "http://blog.csdn.net/xumingming64398966" );
}
});
MenuItem sm = new MenuItem( "Send Mail" );
sm.addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent ae ) {
sendMail( "[email protected]" );
}
});
MenuItem ed = new MenuItem( "Edit" );
ed.addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent ae ) {
edit();
}
});
MenuItem ex = new MenuItem( "Exit" );
ex.addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent ae ) {
System.exit( 0 );
}
});
pm.add( ob );
pm.add( sm );
pm.add( ed );
pm.addSeparator();
pm.add( ex );
}
}
import java.awt.AWTException;
import java.awt.Desktop;
import java.awt.Image;
import java.awt.MenuItem;
import java.awt.PopupMenu;
import java.awt.SystemTray;
import java.awt.Toolkit;
import java.awt.TrayIcon;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
public class DesktopTrayTest{
private static Desktop desktop;
private static SystemTray st;
private static PopupMenu pm;
public static void main( String[] args ) {
if( Desktop.isDesktopSupported() ) {
desktop = Desktop.getDesktop();
}
if( SystemTray.isSupported() ) {
st = SystemTray.getSystemTray();
Image image = Toolkit.getDefaultToolkit().createImage( "http://www.51ppt.com.cn/Article/Uploadphotos/200604/20064147333288.png" );
createPopupMenu();
TrayIcon ti = new TrayIcon( image, "Demo", pm );
try{
st.add( ti );
} catch( AWTException awte ) {
awte.printStackTrace();
}
}
}
public static void sendMail( String mail ) {
if( desktop != null &&
desktop.isSupported( Desktop.Action.MAIL ) ) {
try {
desktop.mail( new URI( mail ) );
} catch (IOException e) {
e.printStackTrace();
} catch (URISyntaxException e) {
e.printStackTrace();
}
}
}
public static void openBrowser( String url ) {
if( desktop != null &&
desktop.isSupported( Desktop.Action.BROWSE )) {
try {
desktop.browse( new URI( url ) );
} catch (IOException e) {
e.printStackTrace();
} catch (URISyntaxException e) {
e.printStackTrace();
}
}
}
public static void edit() {
if( desktop != null &&
desktop.isSupported( Desktop.Action.EDIT ) ) {
File file = new File( "test.txt" );
try {
if( file.exists() == false ) {
file.create();
}
desktop.edit( file );
} catch( IOException ioe ) {
ioe.printStackTrace();
}
}
}
public static void createPopupMenu() {
pm = new PopupMenu();
MenuItem ob = new MenuItem( "Open url" );
ob.addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent ae ) {
openBrowser( "http://blog.csdn.net/xumingming64398966" );
}
});
MenuItem sm = new MenuItem( "Send Mail" );
sm.addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent ae ) {
sendMail( "[email protected]" );
}
});
MenuItem ed = new MenuItem( "Edit" );
ed.addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent ae ) {
edit();
}
});
MenuItem ex = new MenuItem( "Exit" );
ex.addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent ae ) {
System.exit( 0 );
}
});
pm.add( ob );
pm.add( sm );
pm.add( ed );
pm.addSeparator();
pm.add( ex );
}
}
２．Console. JDK6中提供了java.io.Console類專用來訪問基於字符的控制檯設備. 你的程序如果要與Windows下的cmd或者Linux下的Terminal交互,就可以用Console類代勞. 但我們不總是能得到可用的Console, 一個JVM是否有可用的Console依賴於底層平臺和JVM如何被調用. 如果JVM是在交互式命令行(比如Windows的cmd)中啓動的,並且輸入輸出沒有重定向到另外的地方,那麼就可以得到一個可用的Console實例. 下面代碼演示了Console類的用法:
Java代碼
import java.io.Console;
public class ConsoleTest {
public static void main( String[] args ) {
Console console = System.console();
if( console != null ) {
String user = new String( console.readLine( "Enter User:", new Object[ 0 ] ) );
String pwd = new String( console.readPassword( "Enter Password:", new Object[ 0 ] ));
console.printf( "User name is:%s", new Object[]{user} );
console.printf( "Password is:%s", new Object[]{pwd} );
} else {
System.out.println( "No Console!" );
}
}
}
import java.io.Console;
public class ConsoleTest {
public static void main( String[] args ) {
Console console = System.console();
if( console != null ) {
String user = new String( console.readLine( "Enter User:", new Object[ 0 ] ) );
String pwd = new String( console.readPassword( "Enter Password:", new Object[ 0 ] ));
console.printf( "User name is:%s", new Object[]{user} );
console.printf( "Password is:%s", new Object[]{pwd} );
} else {
System.out.println( "No Console!" );
}
}
}
你如果是在一個IDE中如eclipse, netbeans中運行你將得到：
No Console!
因爲只有在命令行中才能得到Console對象。
３．Compiler API. 現在我們可以用JDK6 的Compiler API(JSR 199)去動態編譯Java源文件，Compiler API結合反射功能就可以實現動態的產生Java代碼並編譯執行這些代碼，有點動態語言的特徵。這個特性對於某些需要用到動態編譯的應用程序相當有用，比如JSP Web Server，當我們手動修改JSP後，是不希望需要重啓Web Server纔可以看到效果的，這時候我們就可以用Compiler API來實現動態編譯JSP文件，當然，現在的JSP Web Server也是支持JSP熱部署的，現在的JSP Web Server通過在運行期間通過Runtime.exec或ProcessBuilder來調用javac來編譯代碼，這種方式需要我們產生另一個進程去做編譯工作，不夠優雅而且容易使代碼依賴與特定的操作系統；Compiler API通過一套易用的標準的API提供了更加豐富的方式去做動態編譯,而且是跨平臺的。 下面代碼演示了Compiler API的使用：
Java代碼
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Iterator;
import javax.tools.JavaCompiler;
import javax.tools.JavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;
public class CompilerAPITest {
private final static String srcFileName = "Test.java";
private final static String classFileName = "Test.class";
private final static String className = "Test";
public static void main( String[] args ) {
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
if( compiler == null ) {
System.err.println( "Compiler is null!" );
return;
}
StandardJavaFileManager fileManager = compiler.getStandardFileManager( null, null, null );
generateJavaClass();
Iterable < ? extends JavaFileObject> sourceFiles = fileManager.getJavaFileObjects( new String[]{ srcFileName } );
compiler.getTask( null, fileManager, null, null, null, sourceFiles ).call();
try {
fileManager.close();
Class.forName( className ).newInstance();
} catch (IOException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
public static void generateJavaClass() {
try {
FileWriter rw = new FileWriter( srcFileName );
BufferedWriter bw = new BufferedWriter( rw );
bw.write( "public class " + className + " {" );
bw.newLine();
bw.write( "public " + className + "() {");
bw.newLine();
bw.write( "System.out.println( 'you are in the constructor of Class Test' );" );
bw.write( "}" );
bw.newLine();
bw.write( "}" );
bw.flush();
bw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Iterator;
import javax.tools.JavaCompiler;
import javax.tools.JavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;
public class CompilerAPITest {
private final static String srcFileName = "Test.java";
private final static String classFileName = "Test.class";
private final static String className = "Test";
public static void main( String[] args ) {
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
if( compiler == null ) {
System.err.println( "Compiler is null!" );
return;
}
StandardJavaFileManager fileManager = compiler.getStandardFileManager( null, null, null );
generateJavaClass();
Iterable < ? extends JavaFileObject> sourceFiles = fileManager.getJavaFileObjects( new String[]{ srcFileName } );
compiler.getTask( null, fileManager, null, null, null, sourceFiles ).call();
try {
fileManager.close();
Class.forName( className ).newInstance();
} catch (IOException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
public static void generateJavaClass() {
try {
FileWriter rw = new FileWriter( srcFileName );
BufferedWriter bw = new BufferedWriter( rw );
bw.write( "public class " + className + " {" );
bw.newLine();
bw.write( "public " + className + "() {");
bw.newLine();
bw.write( "System.out.println( 'you are in the constructor of Class Test' );" );
bw.write( "}" );
bw.newLine();
bw.write( "}" );
bw.flush();
bw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
JDK1.6.0新特性詳解與代碼示例
JDK6.0發佈有段時間了，新的JDK也有不少新的特性，我去網上搜集了一下，列在下面和大家一起學習．
１．Desktop和SystemTray. 在JDK6中 ,AWT新增加了兩個類:Desktop和SystemTray,前者可以用來打開系統默認瀏覽器瀏覽指定的URL,打開系統默認郵件客戶端給指定的郵箱發郵件,用默認應用程序打開或編輯文件(比如,用記事本打開以txt爲後綴名的文件),用系統默認的打印機打印文檔;後者可以用來在系統托盤區創建一個托盤程序。
我隨便找了幾張圖，在Tray裏面都是空的，沒有圖,可能是圖太大，有xdjm知道希望告訴我．
import java.awt.AWTException;
import java.awt.Desktop;
import java.awt.Image;
import java.awt.MenuItem;
import java.awt.PopupMenu;
import java.awt.SystemTray;
import java.awt.Toolkit;
import java.awt.TrayIcon;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
public class DesktopTrayTest {
private static Desktop desktop;
private static SystemTray st;
private static PopupMenu pm;
public static void main( String[] args ) {
if( Desktop.isDesktopSupported() ) {
desktop = Desktop.getDesktop();
}
if( SystemTray.isSupported() ) {
st = SystemTray.getSystemTray();
Image image = Toolkit.getDefaultToolkit().createImage( "http://www.51ppt.com.cn/Article/Uploadphotos/200604/20064147333288.png" );
createPopupMenu();
TrayIcon ti = new TrayIcon( image, "Demo", pm );
try{
st.add( ti );
} catch( AWTException awte ) {
awte.printStackTrace();
}
}
}
public static void sendMail( String mail ) {
if( desktop != null &&
desktop.isSupported( Desktop.Action.MAIL ) ) {
try {
desktop.mail( new URI( mail ) );
} catch (IOException e) {
e.printStackTrace();
} catch (URISyntaxException e) {
e.printStackTrace();
}
}
}
public static void openBrowser( String url ) {
if( desktop != null &&
desktop.isSupported( Desktop.Action.BROWSE )) {
try {
desktop.browse( new URI( url ) );
} catch (IOException e) {
e.printStackTrace();
} catch (URISyntaxException e) {
e.printStackTrace();
}
}
}
public static void edit() {
if( desktop != null &&
desktop.isSupported( Desktop.Action.EDIT ) ) {
File file = new File( "test.txt" );
try {
if( file.exists() == false ) {
file.create();
}
desktop.edit( file );
} catch( IOException ioe ) {
ioe.printStackTrace();
}
}
}
public static void createPopupMenu() {
pm = new PopupMenu();
MenuItem ob = new MenuItem( "Open url" );
ob.addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent ae ) {
openBrowser( "http://blog.csdn.net/xumingming64398966" );
}
});
MenuItem sm = new MenuItem( "Send Mail" );
sm.addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent ae ) {
sendMail( "[email protected]" );
}
});
MenuItem ed = new MenuItem( "Edit" );
ed.addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent ae ) {
edit();
}
});
MenuItem ex = new MenuItem( "Exit" );
ex.addActionListener( new ActionListener() {
public void actionPerformed( ActionEvent ae ) {
System.exit( 0 );
}
});
pm.add( ob );
pm.add( sm );
pm.add( ed );
pm.addSeparator();
pm.add( ex );
}
}
２．Console. JDK6中提供了java.io.Console類專用來訪問基於字符的控制檯設備. 你的程序如果要與Windows下的cmd或者Linux下的Terminal交互,就可以用Console類代勞. 但我們不總是能得到可用的Console, 一個JVM是否有可用的Console依賴於底層平臺和JVM如何被調用. 如果JVM是在交互式命令行(比如Windows的cmd)中啓動的,並且輸入輸出沒有重定向到另外的地方,那麼就可以得到一個可用的Console實例. 下面代碼演示了Console類的用法:
import java.io.Console;
public class ConsoleTest {
public static void main( String[] args ) {
Console console = System.console();
if( console != null ) {
String user = new String( console.readLine( "Enter User:", new Object[ 0 ] ) );
String pwd = new String( console.readPassword( "Enter Password:", new Object[ 0 ] ));
console.printf( "User name is:%s", new Object[]{user} );
console.printf( "Password is:%s", new Object[]{pwd} );
} else {
System.out.println( "No Console!" );
}
}
}
你如果是在一個IDE中如eclipse, netbeans中運行你將得到：
No Console!
因爲只有在命令行中才能得到Console對象。
３．Compiler API. 現在我們可以用JDK6 的Compiler API(JSR 199)去動態編譯Java源文件，Compiler API結合反射功能就可以實現動態的產生Java代碼並編譯執行這些代碼，有點動態語言的特徵。這個特性對於某些需要用到動態編譯的應用程序相當有用，比如JSP Web Server，當我們手動修改JSP後，是不希望需要重啓Web Server纔可以看到效果的，這時候我們就可以用Compiler API來實現動態編譯JSP文件，當然，現在的JSP Web Server也是支持JSP熱部署的，現在的JSP Web Server通過在運行期間通過Runtime.exec或ProcessBuilder來調用javac來編譯代碼，這種方式需要我們產生另一個進程去做編譯工作，不夠優雅而且容易使代碼依賴與特定的操作系統；Compiler API通過一套易用的標準的API提供了更加豐富的方式去做動態編譯,而且是跨平臺的。 下面代碼演示了Compiler API的使用：
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.Iterator;
import javax.tools.JavaCompiler;
import javax.tools.JavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;
public class CompilerAPITest {
private final static String srcFileName = "Test.java";
private final static String classFileName = "Test.class";
private final static String className = "Test";
public static void main( String[] args ) {
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
if( compiler == null ) {
System.err.println( "Compiler is null!" );
return;
}
StandardJavaFileManager fileManager = compiler.getStandardFileManager( null, null, null );
generateJavaClass();
Iterable < ? extends JavaFileObject> sourceFiles = fileManager.getJavaFileObjects( new String[]{ srcFileName } );
compiler.getTask( null, fileManager, null, null, null, sourceFiles ).call();
try {
fileManager.close();
Class.forName( className ).newInstance();
} catch (IOException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
public static void generateJavaClass() {
try {
FileWriter rw = new FileWriter( srcFileName );
BufferedWriter bw = new BufferedWriter( rw );
bw.write( "public class " + className + " {" );
bw.newLine();
bw.write( "public " + className + "() {");
bw.newLine();
bw.write( "System.out.println( 'you are in the constructor of Class Test' );" );
bw.write( "}" );
bw.newLine();
bw.write( "}" );
bw.flush();
bw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
我在運行這個例子的時候發現ToolProvider.getSystemJavaCompiler得到的是NULL,後來上網一查，原來是一個Bug!鏈接如下：
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6477844
Closed, not reproducible
那爲什麼我一直在reproduce阿？
4.Http Server API. JDK6提供了一個簡單的Http Server API,據此我們可以構建自己的嵌入式Http Server,它支持Http和Https協議,提供了HTTP1.1的部分實現，沒有被實現的那部分可以通過擴展已有的Http Server API來實現,程序員必須自己實現HttpHandler接口,HttpServer會調用HttpHandler實現類的回調方法來處理客戶端請求,在這裏,我們把一個Http請求和它的響應稱爲一個交換,包裝成HttpExchange類,HttpServer負責將HttpExchange傳給 HttpHandler實現類的回調方法.下面代碼演示了怎樣創建自己的Http Server .
Java代碼
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpServer;
public class HttpServerAPITest {
private static int count = 0;
public static void main( String[] args ) {
try {
HttpServer hs = HttpServer.create( new InetSocketAddress( 8888 ), 0 );
hs.createContext( "/", new MyHandler() );
hs.createContext( "/java", new MyHandler() );
hs.setExecutor( null );
hs.start();
System.out.println( "---begin---" );
System.out.println( "Listening on " + hs.getAddress() );
} catch( IOException ioe ) {
ioe.printStackTrace();
}
}
static class MyHandler implements HttpHandler {
public void handle( HttpExchange he ) throws IOException {
System.out.println( "Request " + count++ );
System.out.println( he.getHttpContext().getPath() );
InputStream is = he.getRequestBody();
String response = "<font color='blue'>Happy Spring Festerval</font>";
he.sendResponseHeaders( 200, response.length() );
OutputStream os = he.getResponseBody();
os.write( response.getBytes() );
os.close();
}
}
}
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpServer;
public class HttpServerAPITest {
private static int count = 0;
public static void main( String[] args ) {
try {
HttpServer hs = HttpServer.create( new InetSocketAddress( 8888 ), 0 );
hs.createContext( "/", new MyHandler() );
hs.createContext( "/java", new MyHandler() );
hs.setExecutor( null );
hs.start();
System.out.println( "---begin---" );
System.out.println( "Listening on " + hs.getAddress() );
} catch( IOException ioe ) {
ioe.printStackTrace();
}
}
static class MyHandler implements HttpHandler {
public void handle( HttpExchange he ) throws IOException {
System.out.println( "Request " + count++ );
System.out.println( he.getHttpContext().getPath() );
InputStream is = he.getRequestBody();
String response = "<font color='blue'>Happy Spring Festerval</font>";
he.sendResponseHeaders( 200, response.length() );
OutputStream os = he.getResponseBody();
os.write( response.getBytes() );
os.close();
}
}
}
5.對腳本語言的支持如: ruby, groovy, javascript.
Java代碼
import java.io.FileReader;
import javax.script.Invocable;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
public class ScriptTest {
public static void main( String[] args ) {
ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName( "ECMAScript" );
try {
engine.eval( new FileReader( "C:/test.js" ) );
Invocable invocableEngine = (Invocable)engine;
Object ret = invocableEngine.invokeFunction( "test", null );
System.out.println( "The result is :" + (Double)ret );
} catch( Exception e ) {
e.printStackTrace();
}
}
}
test.js如下:
function test(){
return Math.round( 11.2 );
}
import java.io.FileReader;
import javax.script.Invocable;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
public class ScriptTest {
public static void main( String[] args ) {
ScriptEngineManager manager = new ScriptEngineManager();
ScriptEngine engine = manager.getEngineByName( "ECMAScript" );
try {
engine.eval( new FileReader( "C:/test.js" ) );
Invocable invocableEngine = (Invocable)engine;
Object ret = invocableEngine.invokeFunction( "test", null );
System.out.println( "The result is :" + (Double)ret );
} catch( Exception e ) {
e.printStackTrace();
}
}
}
test.js如下:
function test(){
return Math.round( 11.2 );
}
6.插入式註解處理API(Pluggable Annotation Processing API)，插入式註解處理API(JSR 269)提供一套標準API來處理Annotations.JSR 269用Annotation Processor在編譯期間而不是運行期間處理Annotation, Annotation Processor相當於編譯器的一個插件,所以稱爲插入式註解處理.如果Annotation Processor處理Annotation時(執行process方法)產生了新的Java代碼,編譯器會再調用一次Annotation Processor,如果第二次處理還有新代碼產生,就會接着調用Annotation Processor,直到沒有新代碼產生爲止.每執行一次process()方法被稱爲一個"round",這樣整個Annotation processing過程可以看作是一個round的序列.
舉個例子：們想建立一套基於Annotation的單元測試框架(如TestNG),在測試類裏面用Annotation來標識測試期間需要執行的測試方法,如下所示:
Java代碼
@TestMethod
public void testCheckName(){
//do something here
}
@TestMethod
public void testCheckName(){
//do something here
}
這時我們就可以用JSR 269提供的API來處理測試類,根據Annotation提取出需要執行的測試方法.
再舉個例子: 下面我用代碼演示如何來用JSR 269提供的API來處理Annotations和讀取Java源文件的元數據(metadata)
Java代碼
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.annotation.processing.AbstractProcessor;
import javax.annotation.processing.RoundEnvironment;
import javax.annotation.processing.SupportedAnnotationTypes;
import javax.annotation.processing.SupportedSourceVersion;
import javax.lang.model.SourceVersion;
import javax.lang.model.element.AnnotationMirror;
import javax.lang.model.element.AnnotationValue;
import javax.lang.model.element.Element;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.TypeElement;
import javax.lang.model.util.ElementFilter;
import javax.tools.Diagnostic.Kind;
@SupportedAnnotationTypes( "ToBeTested" )
@SupportedSourceVersion( SourceVersion.RELEASE_6 )
public class MyAnnotationProcessor extends AbstractProcessor {
private void note( String msg ) {
processingEnv.getMessager().printMessage( Kind.NOTE, msg );
}
public boolean process( Set< ? extends TypeElement > annotations, RoundEnvironment roundEnv ) {
for( TypeElement te : annotations ) {
note( "annotation: " + te.toString() );
}
Set< ? extends Element > elements = roundEnv.getRootElements();
for( Element e : elements ) {
List< ? extends Element > enclosedElems = e.getEnclosedElements();
List< ? extends ExecutableElement > ees = ElementFilter.methodsIn( enclosedElems );
for( ExecutableElement ee : ees ) {
note( "Executable Element Name: " + ee.getSimpleName() );
List< ? extends AnnotationMirror > as = ee.getAnnotationMirrors();
note( " as: " + as );
for( AnnotationMirror am : as ){
Map< ? extends ExecutableElement, ? extends AnnotationValue > map = am.getElementValues();
Set< ? extends ExecutableElement > ks = map.keySet();
for( ExecutableElement k : ks ) {
AnnotationValue av = map.get( k );
note("----"+ee.getSimpleName()+"."+k.getSimpleName()+"="+av.getValue());
}
}
}
}
return false;
}
}
public class Testing {
@ToBeTested(group="A")
public void m1(){
}
@ToBeTested(group="B",owner="QQ")
public void m2(){
}
}
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Retention( RetentionPolicy.RUNTIME )
@Target( ElementType.METHOD )
public @interface ToBeTested {
String owner() default "Chinajash";
String group();
}
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.annotation.processing.AbstractProcessor;
import javax.annotation.processing.RoundEnvironment;
import javax.annotation.processing.SupportedAnnotationTypes;
import javax.annotation.processing.SupportedSourceVersion;
import javax.lang.model.SourceVersion;
import javax.lang.model.element.AnnotationMirror;
import javax.lang.model.element.AnnotationValue;
import javax.lang.model.element.Element;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.TypeElement;
import javax.lang.model.util.ElementFilter;
import javax.tools.Diagnostic.Kind;
@SupportedAnnotationTypes( "ToBeTested" )
@SupportedSourceVersion( SourceVersion.RELEASE_6 )
public class MyAnnotationProcessor extends AbstractProcessor {
private void note( String msg ) {
processingEnv.getMessager().printMessage( Kind.NOTE, msg );
}
public boolean process( Set< ? extends TypeElement > annotations, RoundEnvironment roundEnv ) {
for( TypeElement te : annotations ) {
note( "annotation: " + te.toString() );
}
Set< ? extends Element > elements = roundEnv.getRootElements();
for( Element e : elements ) {
List< ? extends Element > enclosedElems = e.getEnclosedElements();
List< ? extends ExecutableElement > ees = ElementFilter.methodsIn( enclosedElems );
for( ExecutableElement ee : ees ) {
note( "Executable Element Name: " + ee.getSimpleName() );
List< ? extends AnnotationMirror > as = ee.getAnnotationMirrors();
note( " as: " + as );
for( AnnotationMirror am : as ){
Map< ? extends ExecutableElement, ? extends AnnotationValue > map = am.getElementValues();
Set< ? extends ExecutableElement > ks = map.keySet();
for( ExecutableElement k : ks ) {
AnnotationValue av = map.get( k );
note("----"+ee.getSimpleName()+"."+k.getSimpleName()+"="+av.getValue());
}
}
}
}
return false;
}
}
public class Testing {
@ToBeTested(group="A")
public void m1(){
}
@ToBeTested(group="B",owner="QQ")
public void m2(){
}
}
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
@Retention( RetentionPolicy.RUNTIME )
@Target( ElementType.METHOD )
public @interface ToBeTested {
String owner() default "Chinajash";
String group();
}
7.StAX. StAX是The Streaming API for XML的縮寫，是繼DOM(Document Object Model)和SAX(Simple API for XML)之後的又一種處理xml的api,一種利用拉模式解析(pull-parsing)XML文檔的API.StAX通過提供一種基於事件迭代器(Iterator)的API讓程序員去控制xml文檔解析過程,程序遍歷這個事件迭代器去處理每一個解析事件，解析事件可以看做是程序拉出來的，也就是程序促使解析器產生一個解析事件然後處理該事件，之後又促使解析器產生下一個解析事件，如此循環直到碰到文檔結束符；SAX也是基於事件處理xml文檔，但卻是用推模式解析，解析器解析完整個xml文檔後，才產生解析事件，然後推給程序去處理這些事件；DOM採用的方式是將整個xml文檔映射到一顆內存樹，這樣就可以很容易地得到父節點和子結點以及兄弟節點的數據，但如果文檔很大，將會嚴重影響性能。
下面是個例子：
Java代碼
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import javax.xml.stream.events.StartElement;
import javax.xml.stream.events.XMLEvent;
public class StaxTest {
public static void main( String[] arg ) throws XMLStreamException, FileNotFoundException {
readXMLByStAX();
writeXMLByStAX();
}
public static void readXMLByStAX() throws XMLStreamException, FileNotFoundException {
XMLInputFactory factory = XMLInputFactory.newInstance();
XMLEventReader reader = factory.createXMLEventReader( StaxTest.class.getResourceAsStream( "test.xml" ) );
XMLEvent event;
StringBuffer parsingResult = new StringBuffer();
while( reader.hasNext() ) {
event = reader.nextEvent();
if( event.isStartElement() ) {
StartElement se = event.asStartElement();
parsingResult.append( "<" );
parsingResult.append( se.getName() );
if( se.getName().getLocalPart().equals( "catalog" ) ) {
parsingResult.append( "id="" );
parsingResult.append( se.getAttributeByName( new QName( "id" ) ).getValue());
parsingResult.append( """ ) ;
}
parsingResult.append( ">" );
} else if( event.isCharacters() ) {
parsingResult.append( event.asCharacters().getData() );
} else if( event.isEndElement() ) {
parsingResult.append( "</" );
parsingResult.append( event.asEndElement().getName() );
parsingResult.append( ">" );
}
}
System.out.println( parsingResult );
}
public static void writeXMLByStAX() throws XMLStreamException, FileNotFoundException {
XMLOutputFactory factory = XMLOutputFactory.newInstance();
XMLStreamWriter writer = factory.createXMLStreamWriter( new FileOutputStream( "output.xml" ) );
writer.writeStartDocument();
writer.writeCharacters( " " );
writer.writeComment( "testing comment" );
writer.writeCharacters( " " );
writer.writeStartElement( "catalogs" );
writer.writeNamespace( "myNS", "http://blog.csdn.net/Chinajash" );
writer.writeAttribute( "owner", "sina" );
writer.writeCharacters( " " );
writer.writeStartElement("http://blog.csdn.net/Chinajash", "catalog");
writer.writeAttribute("id","007");
writer.writeCharacters("Apparel");
// 寫入catalog元素的結束標籤
writer.writeEndElement();
// 寫入catalogs元素的結束標籤
writer.writeEndElement();
// 結束 XML 文檔
writer.writeEndDocument();
writer.close();
}
}
test.xml:
<?xml version="1.0" encoding="UTF-8"?>
<catalogs>
<catalog id="001">Book</catalog>
<catalog id="002">Video</catalog>
</catalogs>
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLOutputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import javax.xml.stream.events.StartElement;
import javax.xml.stream.events.XMLEvent;
public class StaxTest {
public static void main( String[] arg ) throws XMLStreamException, FileNotFoundException {
readXMLByStAX();
writeXMLByStAX();
}
public static void readXMLByStAX() throws XMLStreamException, FileNotFoundException {
XMLInputFactory factory = XMLInputFactory.newInstance();
XMLEventReader reader = factory.createXMLEventReader( StaxTest.class.getResourceAsStream( "test.xml" ) );
XMLEvent event;
StringBuffer parsingResult = new StringBuffer();
while( reader.hasNext() ) {
event = reader.nextEvent();
if( event.isStartElement() ) {
StartElement se = event.asStartElement();
parsingResult.append( "<" );
parsingResult.append( se.getName() );
if( se.getName().getLocalPart().equals( "catalog" ) ) {
parsingResult.append( "id="" );
parsingResult.append( se.getAttributeByName( new QName( "id" ) ).getValue());
parsingResult.append( """ ) ;
}
parsingResult.append( ">" );
} else if( event.isCharacters() ) {
parsingResult.append( event.asCharacters().getData() );
} else if( event.isEndElement() ) {
parsingResult.append( "</" );
parsingResult.append( event.asEndElement().getName() );
parsingResult.append( ">" );
}
}
System.out.println( parsingResult );
}
public static void writeXMLByStAX() throws XMLStreamException, FileNotFoundException {
XMLOutputFactory factory = XMLOutputFactory.newInstance();
XMLStreamWriter writer = factory.createXMLStreamWriter( new FileOutputStream( "output.xml" ) );
writer.writeStartDocument();
writer.writeCharacters( " " );
writer.writeComment( "testing comment" );
writer.writeCharacters( " " );
writer.writeStartElement( "catalogs" );
writer.writeNamespace( "myNS", "http://blog.csdn.net/Chinajash" );
writer.writeAttribute( "owner", "sina" );
writer.writeCharacters( " " );
writer.writeStartElement("http://blog.csdn.net/Chinajash", "catalog");
writer.writeAttribute("id","007");
writer.writeCharacters("Apparel");
// 寫入catalog元素的結束標籤
writer.writeEndElement();
// 寫入catalogs元素的結束標籤
writer.writeEndElement();
// 結束 XML 文檔
writer.writeEndDocument();
writer.close();
}
}
test.xml:
<?xml version="1.0" encoding="UTF-8"?>
<catalogs>
<catalog id="001">Book</catalog>
<catalog id="002">Video</catalog>
</catalogs>
8. Web Service. 由於Web服務日趨流行，利用Web服務的功能性的API特徵正從最新的Java EE版本中向Java SE 6平臺遷移。換言之，針對Web服務不需另外加入額外的工具，在Java EE和Java SE平臺擁有相同的API。野馬將大把不同的Web服務相關的API加到標準的工具櫃中：以JSR 181針對Java 平臺的Web服務元數據，通過JSR 224的基於XML 的Web服務Java API（JAX-WS）；針對Java的帶有附件的SOAP API（SAAJ）作爲JSR 67 。與三個Web服務API相關的包新增到Java SE 6.0裏：JAX－WS API 放置到javax.xml.ws包； SAAJ類在javax.xml.soap 包； Web服務的元數據類放置在javax.jws包裏。 下面是一個簡單的例子， 下面的代碼是要作爲web service發佈的類。
Java代碼
package hello;
import javax.jws.WebService;
import javax.xml.ws.Endpoint;
@WebService
public class CircleFunctions {
public double getArea( int radius ) {
return Math.PI * radius * radius;
}
public double getCircumference( int radius ) {
return Math.PI * radius * 2;
}
public static void main( String[] args ) {
Endpoint.publish( "http://localhost:8888/WebServiceExample/circlefunctions", new CircleFunctions());
}
}
package hello;
import javax.jws.WebService;
import javax.xml.ws.Endpoint;
@WebService
public class CircleFunctions {
public double getArea( int radius ) {
return Math.PI * radius * radius;
}
public double getCircumference( int radius ) {
return Math.PI * radius * 2;
}
public static void main( String[] args ) {
Endpoint.publish( "http://localhost:8888/WebServiceExample/circlefunctions", new CircleFunctions());
}
}
處理的方法如下：
javac -d ./ CircleFunctions.java
wsgen hello.CircleFunctions
java hello.CircleFunctions
然後在瀏覽器中輸入如下url,你將得到一個xml頁面：
http: //localhost:8888/WebServiceExample/circlefunctions?WSDL
參考網頁：
1.Desktop和SystemTray. http://dev.yesky.com/411/3019911.shtml
2.Console. http://dev.yesky.com/133/3032133.shtml
3.Compiler API. http://developer.51cto.com/art/200701/37359.htm
4.HttpServer API. http://www.testage.net/QA/Dev/200701/1396.htm
5. 對腳本語言的支持http://blog.edwardro.com/read.php?167
6. 插入式註解處理API. http://ourconan.com.cn/article.php?itemid-2113-type-blog.html
7.StAX. http://ourconan.com.cn/article.php?itemid-2111-type-blog.html
8.Web Service. http://www.360doc.com/showWeb/0/0/298124.aspx
9.JDK1.5的Annotation
本文來自CSDN博客，轉載請標明出處：http://blog.csdn.net/stevexk/archive/2008/03/26/2219158.aspx