过滤器实现统一编码

package org.zln.utils.filter;

import javax.servlet.*;
import java.io.IOException;

/**
 * Created by sherry on 2015/2/6 0006 15:40.
 */
public class CharactorFilter implements Filter {
    String encoding = null;
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        encoding = filterConfig.getInitParameter("encoding");
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        if (encoding != null){
            servletRequest.setCharacterEncoding(encoding);
            servletResponse.setContentType("text/html;charset="+encoding);
            System.out.println(" ---字符过滤---"+encoding);
        }
        filterChain.doFilter(servletRequest,servletResponse);
    }

    @Override
    public void destroy() {
        encoding = null;
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">

    <!--字符过滤器-->
    <filter>
        <filter-name>CharactorFilter</filter-name>
        <filter-class>org.zln.utils.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>

</web-app>