如何解决Tomcat下中文乱码问题？

现在将常见的乱码问题分为JSP页面显示中文乱码、表单提交乱码两类。

     1）JSP页面中显示中文乱码

     在JSP文件中使用page命令指定响应结果的MIME类型，如<%@ page language="java" contentType="text/html;charset=gb2312" %>

     2）表单提交乱码   

     表单提交时（post和Get方法），使用request.getParameter方法得到乱码，这是因为tomcat处理提交的参数时默认的是iso-8859-1，表单提交get和post处理乱码问题不同，下面分别说明。
    (1)POST处理
    对post提交的表单通过编写一个过滤器的方法来解决，过滤器在用户提交的数据被处理之前被调用，可以在这里改变参数的编码方式，过滤器的代码如下：

package example.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;

    public class SetCharacterEncodingFilter implements Filter {

       protected String encoding = null;

       protected FilterConfig filterConfig = null;

       protected boolean ignore = true;


     public void destroy() {

      this.encoding = null;
      this.filterConfig = null;

     }

     public void doFilter(ServletRequest request, ServletResponse response,
      <STRONG><SPAN style="COLOR: #ff0000"> FilterChain chain) throws IOException, ServletException {

          if (ignore || (request.getCharacterEncoding() == null)) {
       String encoding = selectEncoding(request);
       if (encoding != null) {
        request.setCharacterEncoding(encoding);
       }
      }</SPAN>
</STRONG>
      // Pass control on to the next filter
      chain.doFilter(request, response);

     }
    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 String selectEncoding(ServletRequest request) {

      return (this.encoding);

     }

    }

package example.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;
    
    public class SetCharacterEncodingFilter implements Filter {
    
       protected String encoding = null;
    
       protected FilterConfig filterConfig = null;
    
       protected boolean ignore = true;
    
  
     public void destroy() {
    
      this.encoding = null;
      this.filterConfig = null;
    
     }
    
     public void doFilter(ServletRequest request, ServletResponse response,
       FilterChain chain) throws IOException, ServletException {
    
          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);
    
     }
    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 String selectEncoding(ServletRequest request) {
    
      return (this.encoding);
    
     }
    
    }

 

    文中红色的代码即为处理乱码的代码。
      web.xml文件加入过滤器

 

<filter>
    <filter-name>Encoding</filter-name>
    <filter-class>
            example.util.SetCharacterEncodingFilter
     </filter-class>
    <init-param>
   <param-name>encoding</param-name>
   <param-value>gbk</param-value>
   <!--gbk或者gb2312或者utf-8-->
  </init-param>
  <init-param>
   <param-name>ignore</param-name>
   <param-value>true</param-value>
  </init-param>
 </filter>

<filter>
    <filter-name>Encoding</filter-name>
    <filter-class>
            example.util.SetCharacterEncodingFilter
     </filter-class>
    <init-param>
   <param-name>encoding</param-name>
   <param-value>gbk</param-value>
   <!--gbk或者gb2312或者utf-8-->
  </init-param>
  <init-param>
   <param-name>ignore</param-name>
   <param-value>true</param-value>
  </init-param>
 </filter>

<filter-mapping>
  <filter-name>Encoding</filter-name>
  <servlet-name>/*</servlet-name>
 </filter-mapping>

<filter-mapping>
  <filter-name>Encoding</filter-name>
  <servlet-name>/*</servlet-name>
 </filter-mapping>

 

(2) Get方法的处理
 tomcat对post和get的处理方法不一样，所以过滤器不能解决get的乱码问题，它需要在其他地方设置。
 打开<tomcat_home>\conf目录下server.xml文件，找到对8080端口进行服务的Connector组件的设置部分，给这个组件添加一个属性：URIEncoding="GBK"。修改后的Connector设置为：
  

<Connector port="8080" maxHttpHeaderSize="8192"
               maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
               enableLookups="false" redirectPort="8443" acceptCount="100"
               connectionTimeout="20000" disableUploadTimeout="true" <SPAN style="COLOR: #ff0000">URIEncoding="GBK"</SPAN> />

<Connector port="8080" maxHttpHeaderSize="8192"
               maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
               enableLookups="false" redirectPort="8443" acceptCount="100"
               connectionTimeout="20000" disableUploadTimeout="true" URIEncoding="GBK" />

  * 注意修改后重新启动tomcat才能起作用。