轉載於：http://blog.csdn.net/yzh54ak/article/details/5880616
一、JSP頁面顯示亂碼
下面的顯示頁面(display.jsp)就出現亂碼：
<html>
<head>
<title>JSP的中文處理</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
</head>
<body>
<%
out.print("JSP的中文處理");
%>
</body>
</html>
對不同的WEB服務器和不同的JDK版本，處理結果就不一樣。原因：服務器使用的編碼方式不同和瀏覽器
對不同的字符顯示結果不同而導致的。解決辦法：在JSP頁面中指定編碼方式(gb2312),即在頁面的第一行加上：<%@ page contentType="text/html; charset=gb2312"%>，就可以消除亂碼了。完整頁面如下
：
<%@ page contentType="text/html; charset=gb2312"%>
<html>
<head>
<title>JSP的中文處理</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
</head>
<body>
<%
out.print("JSP的中文處理");
%>
</body>
</html>
二、表單提交中文時出現亂碼
下面是一個提交頁面(submit.jsp)，代碼如下：
<html>
<head>
<title>JSP的中文處理</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
</head>
<body>
<form name="form1" method="post" action="process.jsp">
<div align="center">
<input type="text" name="name">
<input type="submit" name="Submit" value="Submit">
</div>
</form>
</body>
</html>
下面是處理頁面(process.jsp)代碼：
<%@ page contentType="text/html; charset=gb2312"%>
<html>
<head>
<title>JSP的中文處理</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
</head>
<body>
<%=request.getParameter("name")%>
</body>
</html>
如果submit.jsp提交英文字符能正確顯示，如果提交中文時就會出現亂碼。原因：瀏覽器默認使用UTF-8編碼方式來發送請求，而UTF- 8和GB2312編碼方式表示字符時不一樣，這樣就出現了不能識別字符。
解決辦法:通過request.setCharacterEncoding ("gb2312")對請求進行統一編碼，就實現了中文的正常顯示。修改後的process.jsp代碼如下：
<%@ page contentType="text/html; charset=gb2312"%>
<%
request.setCharacterEncoding("gb2312");
%>
<html>
<head>
<title>JSP的中文處理</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
</head>
<body>
<%=request.getParameter("name")%>
</body>
</html>
三、數據庫連接出現亂碼
只要涉及中文的地方全部是亂碼，解決辦法：在數據庫的數據庫URL中加上
useUnicode=true&characterEncoding=GBK 就OK了。
四、數據庫的顯示亂碼
在mysql4.1.0中,varchar類型，text類型就會出現中文亂碼，對於varchar類型把它設爲binary屬性就可以解決中文問題，對於text類型就要用一個編碼轉換類來處理，實現如下：
public class Convert {
/** 把ISO-8859-1碼轉換成GB2312
*/
public static String ISOtoGB(String iso){
String gb;
try{
if(iso.equals("") || iso == null){
return "";
}
else{
iso = iso.trim();
gb = new String(iso.getBytes("ISO-8859-1"),"GB2312");
return gb;
}
}
catch(Exception e){
System.err.print("編碼轉換錯誤："+e.getMessage());
return "";
}
}
}
把它編譯成class，就可以調用Convert類的靜態方法ISOtoGB()來轉換編碼。
總結：
1. 在jsp中<%@ page contentType="text/html; charset=A" %>如果指定了，那麼在改jsp中所有構造的String（不是引用），如果沒有指定編碼，那麼這些String的編碼是A的。從request的得到的String如果沒有指定request的編碼的話，他是iso-8859-1的。從別的地方得到的String是使用原來初始的編碼的，比如從數據庫得到String,如果數據庫的編碼是B,那麼該String的編碼是B而不是A的，也不是系統默認的。 此時，如果要輸出的String的編碼不是A,那麼，很可能顯示亂碼的，所以首先要將String正確轉化爲編碼A的String,然後輸出。
2. 在jsp中<%@ page contentType="text/html; charset=A" %>沒有指定，那麼相當於指定了<%@ page contentType="text/html; charset=ISO-8859-1" %>
3． Servelte中如果執行了像 response.setContentType("text/html;charset=A");説明將response的字符輸出流編碼設置爲A,所有要輸出的String的編碼要轉化爲A的，否則會得到亂碼的。
Servelet中從request得到的String的編碼和jsp中一樣的，但是在servlet java文件中構造的String是使用的系統默認的編碼的。在servelt中從外部得到的String 是使用原來的編碼的，比如從編碼爲B的數據庫得到的數據是編碼爲B的,不是A,也不是系統默認的編碼。
五、Linux 下java中文環境設置
首先，檢查你的 /usr/share/fonts/ttf/gb
目錄下是否裝有中文字體 gbsn00lp.ttf
。如果沒有，也可以用 Windows
字體目錄下的 song.ttf
來代替。將字體文件拷貝到 Java
安裝目錄下的 jre/lib/fonts
下。第二，修改 Java
安裝目錄下的 jre/lib/fonts/fonts.dir
文件，將首行的 72
改爲 73，然後添加下列內容：
gbsn00lp.ttf -Arphic Technology Co.-AR PL SungtiL GB-medium-r-normal--0-0-0-0-c-0-gb2312.1980-0
如果你用的是 song.ttf
，則應該將頭部的 gbsn00lp.ttf
改爲 song.ttf
。
第三，在 Java
安裝目錄下的 jre/lib
目錄中，將字體配置文件 font.properties.zh.Turbo
複製爲 font.properties.zh
。然後修改 font.properties.zh
。將文件中所有的：
-tlc-song-medium-r-normal--*-%d-*-*-c-*-gbk-0 替換爲：
-Arphic Technology Co.-AR PL SungtiL GB-medium-r-normal--0-0-0-0-c-0-gb2312.1980-0
第四，用 JDK
自帶的演示程序 SwingSet2
測試，如果看到中文菜單則說明設置成功。
六、Java Web配置過濾器進行字符編碼
1. 在Web.xml中配置過濾器:
<!-- Example filter to set character encoding on each request -->
<filter>
<filter-name>Set Character Encoding</filter-name>
<filter-class> com.hthk.iisz.born.filter. SetCharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>GBK</param-value>
</init-param>
</filter>
<!-- Example filter mapping to apply the "Set Character Encoding" filter to *all* requests processed by this web application -->
<filter-mapping>
<filter-name>Set Character Encoding</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
2. 編寫過濾器
/*
* 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 com.hthk.iisz.born.filter;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
/**
* <p>Example filter that sets the character encoding to be used in parsing the
* incoming request, either unconditionally or only if the client did not
* specify a character encoding. Configuration of this filter is based on
* the following initialization parameters:</p>
* <ul>
* <li><strong>encoding</strong> - The character encoding to be configured
* for this request, either conditionally or unconditionally based on
* the <code>ignore</code> initialization parameter. This parameter
* is required, so there is no default.</li>
* <li><strong>ignore</strong> - If set to "true", any character encoding
* specified by the client is ignored, and the value returned by the
* <code>selectEncoding()</code> method is set. If set to "false,
* <code>selectEncoding()</code> is called <strong>only</strong> if the
* client has not already specified an encoding. By default, this
* parameter is set to "true".</li>
* </ul>
*
* <p>Although this filter can be used unchanged, it is also easy to
* subclass it and make the <code>selectEncoding()</code> method more
* intelligent about what encoding to choose, based on characteristics of
* the incoming request (such as the values of the <code>Accept-Language</code>
* and <code>User-Agent</code> headers, or a value stashed in the current
* user's session.</p>
*
* @author Craig McClanahan
* @version $Revision: 466607 $ $Date: 2006-10-21 17:09:50 -0600 (Sat, 21 Oct 2006) $
*/
public class SetCharacterEncodingFilter implements Filter {
// ----------------------------------------------------- Instance Variables
/**
* The default character encoding to set for requests that pass through
* this filter.
*/
protected String encoding = null;
/**
* The filter configuration object we are associated with. If this value
* is null, this filter instance is not currently configured.
*/
protected FilterConfig filterConfig = null;
/**
* Should a character encoding specified by the client be ignored?
*/
protected boolean ignore = true;
// --------------------------------------------------------- Public Methods
/**
* Take this filter out of service.
*/
public void destroy() {
this.encoding = null;
this.filterConfig = null;
}
/**
* Select and set (if specified) the character encoding to be used to
* interpret request parameters for this request.
*
* @param request The servlet request we are processing
* @param result The servlet response we are creating
* @param chain The filter chain we are processing
*
* @exception IOException if an input/output error occurs
* @exception ServletException if a servlet error occurs
*/
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain)
throws IOException, ServletException {
// Conditionally select and set the character encoding to be used
if (ignore || (request.getCharacterEncoding() == null)) {
String encoding = selectEncoding(request);
if (encoding != null)
request.setCharacterEncoding(encoding);
}
// Pass control on to the next filter
chain.doFilter(request, response);
}
/**
* Place this filter into service.
*
* @param filterConfig The filter configuration object
*/
public void init(FilterConfig filterConfig) throws ServletException {
this.filterConfig = filterConfig;
this.encoding = filterConfig.getInitParameter("encoding");
String value = filterConfig.getInitParameter("ignore");
if (value == null)
this.ignore = true;
else if (value.equalsIgnoreCase("true"))
this.ignore = true;
else if (value.equalsIgnoreCase("yes"))
this.ignore = true;
else
this.ignore = false;
}
// ------------------------------------------------------ Protected Methods
/**
* Select an appropriate character encoding to be used, based on the
* characteristics of the current request and/or filter initialization
* parameters. If no character encoding should be set, return
* <code>null</code>.
* <p>
* The default implementation unconditionally returns the value configured
* by the <strong>encoding</strong> initialization parameter for this
* filter.
*
* @param request The servlet request we are processing
*/
protected String selectEncoding(ServletRequest request) {
return (this.encoding);
}
}
七、Tomcat處理中文字符編碼
首先JAVA(包括JSP)源文件中很可能包含有中文，而Java和JSP源文件的保存方式是居於字節流的，如果Java和JSP編譯成class文件過程中,使用的編碼方式與源文件的編碼方式不一致，就會出現亂碼。基於這種亂碼，建議在Java文件中儘量不要寫中文（註釋部分不參與編譯，寫中文沒關係），如果必須寫的話，儘量手動帶參數編譯-ecoding GBK或-ecoding gb2312；對於JSP，在文件頭加上<%@page contentType=”text/html;charset=GBK”%>或<%@page contentType=”text/html;charset=gb2312”%>基本上就能解決這類亂碼問題.
Get提交方式的字符編碼修改方法:
更改%TOMCAT_HOME%/conf/server.xml
<Connector port="8080" maxHttpHeaderSize="8192"
maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
enableLookups="false" redirectPort="8443" acceptCount="100"
connectionTimeout="20000" disableUploadTimeout="true" URIEncoding=’TUF-8’ useBodyEncodingForURI="true"./>
Post提交方式的媳婦編碼修改方法:
更改%TOMCAT_HOME%/bin/ catalina.bat或catalina.sh
catalina.bat在第51行添加set CATALINA_OPTS=”-Dfile.encoding=UTF-8”
catalina.sh 在第52行添加export CATALINA_OPTS = "-Dfile.encoding=UTF-8"
八、總結
JAVA Unicode for TOMCAT
1. Edit file <TOMCAT>/conf/server.xml under tag <Connector> to add URIEncoding="UTF-8" useBodyEncodingForURI="true".
2. Edit file <TOMCAT>/bin/catalina.bat for Windows to add set CATALINA_OPTS = "-Dfile.encoding=UTF-8" or <TOMCAT>/bin/catalina.sh for Linux to add export CATALINA_OPTS = "-Dfile.encoding=UTF-8".
3. Set IDE (for example, NetBean, Eclipse and etc) file setting to UTF-8.
4. For all the JSPs, add these two lines:
a. <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
b. <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
5. Create a filter as below:
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
public class EncodingFilter implements Filter {
private String encoding;
private FilterConfig filterConfig;
/**
* @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
*/
public void init(FilterConfig fc) throws ServletException {
this.filterConfig = fc;
this.encoding = filterConfig.getInitParameter("encoding");
}
/**
* @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest,
* javax.servlet.ServletResponse, javax.servlet.FilterChain)
*/
public void doFilter(ServletRequest req, ServletResponse resp,
FilterChain chain) throws IOException, ServletException {
req.setCharacterEncoding(encoding);
chain.doFilter(req, resp);
}
/**
* @see javax.servlet.Filter#destroy()
*/
public void destroy() {
}
}
6. Edit file ../WEB-INF/web.xml to include filter:
<filter>
<filter-name>EncodingFilter</filter-name>
<filter-class>EncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>EncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
