04_过滤器Filter_05_Filter解决全站中文乱码问题（POST方式）

<?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"
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>FilterDemo01</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>

<filter>
<filter-name>CharacterEncodingFilter</filter-name>
<filter-class>com.Higgin.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>charset</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>CharacterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern> <!-- 过滤所有 -->
</filter-mapping>

</web-app>

package com.Higgin.web.servlet;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
* Servlet implementation class ServletTest01
*/
@WebServlet("/ServletTest01")
public class ServletTest01 extends HttpServlet {
private static final long serialVersionUID = 1L;

public ServletTest01() {
super();
}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 response.getWriter().write("中国 加油！China Come on!");
System.out.println("执行ServletTest01---");
}

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request,response);
}

}

package com.Higgin.web.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 CharacterEncodingFilter  implements Filter{

private FilterConfig filterConfig=null;
private String defaultCharset="UTF-8";  //自己先设计一个缺省的编码

@Override
public void init(FilterConfig filterConfig) throws ServletException {
this.filterConfig=filterConfig;
}

@Override
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {

System.out.println("进入doFilter()......");

 String charset=filterConfig.getInitParameter("charset"); //获取配置文件的charset的value
if(charset==null){  //未成功获取charset,就将缺省的defaultCharset赋值给charset
charset=defaultCharset;
}

 request.setCharacterEncoding(charset);
response.setCharacterEncoding(charset);
response.setContentType("text/html;character="+charset);

chain.doFilter(request, response);//让目标资源执行，放行

}

@Override
public void destroy() {

}

}