在默认情况下，如果我们为某个Action定义了拦截器，则这个拦截器会拦截该Action内的所有方法。但在某些情况下，我们不想拦截所有的方法，我们只需要拦截某些特定方法，此时就需要使用struts2拦截器的方法过滤特性。
为了实现方法过滤的特性，struts2提供了一个MethodFilterInterceptor抽象类，它是AbstractInterceptor的子类，如果用户需要自定义的拦截器支持方法过滤特性，应该继承MethodFilterInterceptor，并重写doIntercept(ActionInvocation invocation)方法。
index.jsp :
<%@ page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
function register(){
var targetForm=document.forms[0];
targetForm.action="register";
}
function login(){
var targetForm=document.forms[0];
targetForm.action="login";
}
</script>
</head>
<body>
<s:form action="login_register">
<s:textfield name="name" label="姓名"></s:textfield>
<s:password name="pass" label="密码"></s:password>
<s:submit value="注册" onclick="register();"></s:submit>
<s:submit value="登录" onclick="login();"></s:submit>
</s:form>
</body>
</html>
welcome.jsp :
<%@ page contentType="text/html;charset=UTF-8" pageEncoding="UTF-8"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
<%
Object obj=session.getAttribute("name");
if(obj==null){
response.sendRedirect("index.jsp");
}
%>
${tip} success...
</body>
</html>
struts.xml :
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.1.7//EN"
"http://struts.apache.org/dtds/struts-2.1.7.dtd">
<struts>
<package name="demo" extends="struts-default">
<interceptors>
<interceptor name="methodFilter" class="interceptor.SimpleMethodFilterInterceptor"/>
</interceptors>
<action name="*" class="action.LoginAndRegisterAction" method="{1}">
<result name="success">/welcome.jsp</result>
<result name="error">/index.jsp</result>
<interceptor-ref name="defaultStack"/>
<interceptor-ref name="methodFilter">
<param name="excludeMethods">register</param>
<param name="includeMethods">login</param>
</interceptor-ref>
</action>
</package>
</struts>
SimpleMethodFilterInterceptor.java :
public class SimpleMethodFilterInterceptor extends MethodFilterInterceptor {
@Override
public String doIntercept(ActionInvocation invocation) throws Exception {
System.out.println("Action被拦截之前，当然你可以在这里做点什么...");
String result=invocation.invoke();
System.out.println("Action被拦截之后，当然你可以在这里做点什么...");
return result;
}
}
LoginAndRegisterAction.java :
public class LoginAndRegisterAction extends ActionSupport {
private String name;
private String pass;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPass() {
return pass;
}
public void setPass(String pass) {
this.pass = pass;
}
public String login(){
if(getName().equals("scott")&& getPass().equals("tiger")){
Map<String,Object> session=ActionContext.getContext().getSession();
session.put("name",getName());
session.put("tip","login");
return "success";
}
return "error";
}
public String register(){
if(getName().equals("scott")&& getPass().equals("tiger")){
Map<String,Object> session=ActionContext.getContext().getSession();
session.put("name",getName());
session.put("tip","register");
return "success";
}
return "error";
}
}