Java 的乱码解决方法 统一编码 这里使用UTF-8编码

一、介绍两个类 URLEncoder//编码 URLDecoder//解码 看看下面的测试输出，你就明白是做什么的了 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("中文测试", "UTF-8");//编码   System.out.println(a);   System.out.println(URLDecoder.decode(a,"UTF-8"));//还原   //下面同理   System.out.println("\nGBK(百度就是用这种)");   a = URLEncoder.encode("中文测试", "GBK");   System.out.println(a);   System.out.println(URLDecoder.decode(a,"GBK"));  } } [输出] UTF-8 %E4%B8%AD%E6%96%87%E6%B5%8B%E8%AF%95 中文测试 GBK(百度就是用这种) %D6%D0%CE%C4%B2%E2%CA%D4 中文测试 看了上面的输出就明白百度地址栏那一串是什么了。假如你做了下面一系列设置，那么在服务器端你接收到Get方法的中文参数将被转换成类型%D6%D0%CE%C4%B2%E2%CA%D4 你就需要用到上面的两个工具类, 如果你像我在下面设置，你在上面的调用的第二个参数也得是UTF-8; 使用post就不需要解码,直接读取就行了。 二、配置tomcat (这一步我没有做，但没发现问题，我用的是Tomcat 5.08经典版本) 打开tomcat的server.xml文件，找到区块，加入如下一行： URIEncoding="UTF-8" 完整的应如下： <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、增加连接数据库的参数 mysql 数据库建表时设置编码为utf8(写法不同不是UTF-8), 连接数据库:  // 连接参数，这里设置连接使用的编码  public static final String DB_URL = "jdbc:mysql://localhost:3306/?useUnicode=true&characterEncoding=utf8";   四、使用过滤器设置编码  1、 // 简单的就用下面这个，这里使用的是硬编码也就是在代码中写死了用那种编码我这里用utf-8，也可以把编码设置用写到web.xml中的Filter设置中 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");     // 传递控制到下一个过滤器     chain.doFilter(request, response);     }     public void init(FilterConfig filterConfig) throws ServletException {     } } web.xml配置文件中增加     <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、 //下面这个是将编码设置放到web.xml中的 filter类的内容： /*  * ====================================================================  *  *              JavaWebStudio 开源项目  *                *               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; /**  * 中文过滤器  */ 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 然后我们在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的合适位置。一般在最后，<jsp-config>标签之前(如果有的话)   五、在JSP页面中设置编码 <%@ page language="java" pageEncoding="UTF-8"%>   六、使用i18n 使ApplicationResources.properties支持中文 建立一个ApplicationResources_ISO.properties文件，把应用程序用的message都写进去，然后在dos下执行这个命令， native2ascii -encoding gb2312 ApplicationResources_ISO.properties ApplicationResources.properties native2ascii          [参数]  [输入文件]                          [输出文件] native2ascii这个工具是jdk自带的一个东东，所以如果path都设定正确就可以直接运行了，你可以在$java_home$/bin下找到他。 转换后的中文类似于这个样子 中文格式下 ：user_name_label=用户名： ascii格式下 ：user_name_label=\用\户\名\： Netbean 有个方便的编辑多国语言的工具，但不是直接写，而是在弹出窗口中编辑，确定插入后自动转换成ascii如上面那种. Eclipse 有个一样功能的插件jinto在下面的地址中下载 http://www.guh-software.de/jinto.html 在Jsp页面使用 "user_name_label" 来引用 "用户名：",而且能够简单方便实现多语言支持。 通常将编码同一成UTF-8是很有好处的，如果想使用其他编码如GBK,这上面用到UTF-8全改为GBK   有些东西接触多了就了解，做的多了就熟悉。 声明：这篇只是我自己的总结和备忘录，希望对你有用，上面引用的代码和例子主要来源于网上。