package com;

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 CharacterEncodingFilter implements Filter {

protected String encoding = null;// 定义编码格式变量

protected FilterConfig filterConfig = null;// 定义过滤器配置对象

public void init(FilterConfig filterConfig) throws ServletException {

this.filterConfig = filterConfig; // 初始化过滤器配置对象

this.encoding = filterConfig.getInitParameter("encoding");// 获取配置文件中指定的编码格式

}

// 过滤器的接口方法，用于执行过滤业务

public void doFilter(ServletRequest request, ServletResponse response,

FilterChain chain) throws IOException, ServletException {

if (encoding != null) {

request.setCharacterEncoding(encoding); // 设置请求的编码

response.setContentType("text/html; charset=" + encoding);// 设置应答对象的内容类型（包括编码格式）

}

chain.doFilter(request, response); // 传递给下一个过滤器

}

public void destroy() {

this.encoding = null;

this.filterConfig = null;

}

}