一、介紹兩個類
URLEncoder//編碼
URLDecoder//解碼
看看下面的測試輸出，你就明白是做什麼的了
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;
public class main {
 public static void main(String[] args) throws UnsupportedEncodingException{
  System.out.println("UTF-8");
  String a = URLEncoder.encode("中文測試", "UTF-8");//編碼
  System.out.println(a);
  System.out.println(URLDecoder.decode(a,"UTF-8"));//還原
  //下面同理
  System.out.println("/nGBK(百度就是用這種)");
  a = URLEncoder.encode("中文測試", "GBK");
  System.out.println(a);
  System.out.println(URLDecoder.decode(a,"GBK"));
 }
}
[輸出]
UTF-8
%E4%B8%AD%E6%96%87%E6%B5%8B%E8%AF%95
中文測試
GBK(百度就是用這種)
%D6%D0%CE%C4%B2%E2%CA%D4
中文測試

看了上面的輸出就明白百度位址列那一串是什麼了。假如你做了下面一系列設定，那麼在伺服器端你接收到Get方法的中文引數將被轉換成型別%D6%D0%CE%C4%B2%E2%CA%D4 你就需要用到上面的兩個工具類, 如果你像我在下面設定，你在上面的呼叫的第二個引數也得是UTF-8; 使用post就不需要解碼,直接讀取就行了。

二、配置tomcat (這一步我沒有做，但沒發現問題，我用的是Tomcat 5.08經典版本)
開啟tomcat的server.xml檔案，找到區塊，加入如下一行：
URIEncoding="UTF-8"
完整的應如下：
<Connector port="8080" maxThreads="150" minSpareThreads="25" maxSpareThreads="75" enableLookups="false" redirectPort="8443" acceptCount="100" debug="0" connectionTimeout="20000" disableUploadTimeout="true" URIEncoding="UTF-8"/>

三、增加連線資料庫的引數
mysql 資料庫建表時設定編碼為utf8(寫法不同不是UTF-8),
連線資料庫:
 // 連線引數，這裡設定連線使用的編碼
 public static final String DB_URL = "jdbc:mysql://localhost:3306/?useUnicode=true&characterEncoding=utf8";

四、使用過濾器設定編碼 
1、
// 簡單的就用下面這個，這裡使用的是硬編碼也就是在程式碼中寫死了用那種編碼我這裡用utf-8，也可以把編碼設定用寫到web.xml中的Filter設定中
package com.max;
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;
/**
* Example filter that sets the character encoding to be used in parsing the
* incoming request
*/
public class SetCharacterEncodingFilter implements Filter {
    /**
     * Take this filter out of service.
     */
    public void destroy() {
    }
    /**
     * Select and set (if specified) the character encoding to be used to
     * interpret request parameters for this request.
     */
    public void doFilter(ServletRequest request, ServletResponse response,
    FilterChain chain)throws IOException, ServletException {
    request.setCharacterEncoding("UTF-8");
    // 傳遞控制到下一個過濾器
    chain.doFilter(request, response);
    }
    public void init(FilterConfig filterConfig) throws ServletException {
    }
}

web.xml配置檔案中增加
    <filter>
  <filter-name>Set Character Encoding</filter-name>
  <filter-class>com.max.SetCharacterEncodingFilter</filter-class>
 </filter>
 <filter-mapping>
  <filter-name>Set Character Encoding</filter-name>
  <url-pattern>/*</url-pattern>
 </filter-mapping>

2、
//下面這個是將編碼設定放到web.xml中的
filter類的內容：
/*
 * ====================================================================
 *
 *              JavaWebStudio 開源專案
 *              
 *               Struts_db v0.1
 *
 * ====================================================================
 */
package com.strutsLogin.util;
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;
/**
 * 中文過濾器
 */
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);
 }
}// EOC
然後我們在web.xml中加一些配置，就可以了，配置如下：
<filter>
    <filter-name>Set Character Encoding</filter-name>
    <filter-class>javawebstudio.struts_db.SetCharacterEncodingFilter</filter-class>
    <init-param>
        <param-name>encoding</param-name>
        <param-value>UTF-8</param-value>
    </init-param>
    <init-param>
        <param-name>ignore</param-name>
        <param-value>true</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>Set Character Encoding</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>
放在web.xml的合適位置。一般在最後，<jsp-config>標籤之前(如果有的話)

五、在JSP頁面中設定編碼
<%@ page language="java" pageEncoding="UTF-8"%>

六、使用i18n
使ApplicationResources.properties支援中文
建立一個ApplicationResources_ISO.properties檔案，把應用程式用的message都寫進去，然後在dos下執行這個命令，
native2ascii -encoding gb2312 ApplicationResources_ISO.properties ApplicationResources.properties
native2ascii          [引數]  [輸入檔案]                          [輸出檔案]
native2ascii這個工具是jdk自帶的一個東東，所以如果path都設定正確就可以直接運行了，你可以在$java_home$/bin下找到他。
轉換後的中文類似於這個樣子
中文格式下 ：user_name_label=使用者名稱：
ascii格式下 ：user_name_label=/u7528/u6237/u540D/uFF1A
Netbean 有個方便的編輯多國語言的工具，但不是直接寫，而是在彈出視窗中編輯，確定插入後自動轉換成ascii如上面那種.
Eclipse 有個一樣功能的外掛jinto在下面的地址中下載

http://www.guh-software.de/jinto.html
在Jsp頁面使用 "user_name_label" 來引用 "使用者名稱：",而且能夠簡單方便實現多語言支援。
通常將編碼同一成UTF-8是很有好處的，如果想使用其他編碼如GBK,這上面用到UTF-8全改為GBK