Servlet中通过过滤器实现统一的手动编码(解决中文乱码)

   1.web.xml片段：

　　

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>zhima_demo</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <filter>
    <filter-name>CharactorFilter</filter-name>
    <filter-class>filter.CharactorFilter</filter-class>
    <init-param>
      <param-name>encoding</param-name>
      <param-value>utf-8</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>CharactorFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

 2.实现类片段

package 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;

public class CharactorFilter implements Filter { //继承Filter类
    //字符编码
    private String encoding = null;

    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        if(encoding!=null){
        //设置request字符编码
            request.setCharacterEncoding(encoding);
         //设置response字符编码
            response.setContentType("text/html;charset="+encoding);
        }
        //传递给下一个过滤器
        chain.doFilter(request, response);

    }

    public void init(FilterConfig filterConfig) throws ServletException {
      //获取初始化参数
        encoding=filterConfig.getInitParameter("encoding");

    }

    public void destroy() {
        // TODO Auto-generated method stub
        encoding=null;
    }

}