Servlet中通过过滤器实现统一的手动编码(解决中文乱码)

<?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>

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;
}

}