filter代码
package com.wenq.www.filter;
import java.io.IOException;
import java.util.Date;
import javax.servlet.*;
public class TestFilter implements Filter {
FilterConfig config;
String encoding;
public void destroy() {
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
if(encoding!=null&&!encoding.equals(“”)){
request.setCharacterEncoding(encoding);
System.out.println(“编码为:”+encoding);
}
else {
request.setCharacterEncoding(“GBK”);
}
chain.doFilter(request, response);
}
public void init(FilterConfig config) throws ServletException {
this.config = config;
this.encoding=config.getInitParameter(“encoding”);
System.out.println(“insert encoding:”+encoding);
}
}
web.xml
配置文件：
<filter>
<filter-name>fristFilter</filter-name>
<filter-class>com.wenq.www.filter.TestFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>fristFilter</filter-name>
<servlet-name>*</servlet-name>
</filter-mapping>