<?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>filter</display-name><filter><filter-name>filter01</filter-name><filter-class>com.myfilter.Filter01</filter-class><init-param><param-name>code</param-name><param-value>utf-8</param-value></init-param></filter><filter-mapping><filter-name>filter01</filter-name><url-pattern>/*</url-pattern></filter-mapping><filter><filter-name>filter02</filter-name><filter-class>com.myfilter.Filter02</filter-class></filter><filter-mapping><filter-name>filter02</filter-name><url-pattern>/pages/mainFilter.jsp</url-pattern></filter-mapping><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>
</web-app>

/*** */
package com.myfilter;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;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import org.apache.commons.lang3.StringUtils;/*** @author Administrator**/
public class Filter01 implements Filter
{private String encoding=null;@Overridepublic void destroy(){}@Overridepublic void doFilter(ServletRequest arg0, ServletResponse arg1,FilterChain arg2) throws IOException, ServletException{HttpServletRequest request=(HttpServletRequest)arg0;HttpServletResponse response=(HttpServletResponse)arg1;request.setCharacterEncoding(encoding);response.setCharacterEncoding(encoding);response.setContentType("text/html charset=" encoding);arg2.doFilter(request, response);System.out.println(encoding);}@Overridepublic void init(FilterConfig arg0) throws ServletException{String ww=arg0.getInitParameter("code");if(StringUtils.isNoneBlank(ww)){            encoding=ww;}}}

package com.myfilter;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 Filter02 implements Filter
{@Overridepublic void destroy(){// TODO Auto-generated method stub
}@Overridepublic void doFilter(ServletRequest arg0, ServletResponse arg1,FilterChain arg2) throws IOException, ServletException{System.out.println("第二个过滤器----00001");arg2.doFilter(arg0, arg1);System.out.println("第二个过滤器----00002");}@Overridepublic void init(FilterConfig arg0) throws ServletException{System.out.println("02");}}