Struts2中拦截器与过滤器的执行顺序

web.xml

1. <?xml version="1.0" encoding="UTF-8"?>

2. <web-app version="2.4"

3. xmlns="http://java.sun.com/xml/ns/j2ee"

4. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

5. xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee

6. http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

7.   <welcome-file-list>

8.     <welcome-file>login.jsp</welcome-file>

9.   </welcome-file-list>

10.   

11.   <filter>

12.    <filter-name>MyFilter</filter-name>

13.    <filter-class>filter.MyFilter</filter-class>

14.   </filter>

15.   <filter-mapping>

16.    <filter-name>MyFilter</filter-name>

17.    <url-pattern>/*</url-pattern>

18.   </filter-mapping>

19.   

20.   <filter>

21.    <filter-name>struts2</filter-name>

22.    <filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>

23.   </filter>

24.   <filter-mapping>

25.    <filter-name>struts2</filter-name>

26.    <url-pattern>/*</url-pattern>

27.   </filter-mapping>

28.   

29. </web-app>

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filter.MyFilter

1. package filter;

2. import java.io.IOException;

3. import javax.servlet.Filter;

4. import javax.servlet.FilterChain;

5. import javax.servlet.FilterConfig;

6. import javax.servlet.ServletException;

7. import javax.servlet.ServletRequest;

8. import javax.servlet.ServletResponse;

9. public class MyFilter implements Filter {

10. public void destroy() {

11. }

12. public void doFilter(ServletRequest request, ServletResponse response,

13.    FilterChain chain) throws IOException, ServletException {

14.   

15.   System.out.println("请求过滤");

16.   

17.   chain.doFilter(request, response);

18.   

19.   System.out.println("返回过滤");

20.   

21. }

22. public void init(FilterConfig arg0) throws ServletException {

23. }

24. }

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interceptor.LoginInterceptor

1. package interceptor;

2. import org.apache.struts2.ServletActionContext;

3. import com.opensymphony.xwork2.ActionInvocation;

4. import com.opensymphony.xwork2.interceptor.AbstractInterceptor;

5. public class LoginInterceptor extends AbstractInterceptor {

6. private static final long serialVersionUID = -2796326480994355318L;

7. @Override

8. public String intercept(ActionInvocation ai) throws Exception {

9.   

10.   System.out.println("请求拦截");

11.   

12.   if(!"YOYO".equals(ServletActionContext.getRequest().getParameter("username"))){

13.    return "login";

14.   }

15.   

16.   String result = ai.invoke();

17.   

18.   System.out.println("返回拦截");

19.   

20.   return result;

21. }

22. }

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action.LoginAction

1. package action;

2. public class LoginAction {

4. public String execute(){

5.   System.out.println("登陆ACTION");

6.   

7.   return "success";

8. }

9. }

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index.jsp

1. <%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>

2. <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

3. <html>

4.   <head>

5.     <title>My JSP 'index.jsp' starting page</title>

6.   </head>

7.   

8.   <body>

9.     <h3>Login Success!</h3>

10.   </body>

11. </html>

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login.jsp

1. <%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>

2. <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

3. <html>

4.   <head>

5.     <title>My JSP 'index.jsp' starting page</title>

6.   </head>

7.   

8.   <body>

9.     <h3>Login</h3>

10.     <hr>

11.     <form action="Login.action" method="OST">

12.      Name: <input type="text" name="username" />

13.      <input type="submit" value="submit" />

14.     </form>

15.   </body>

16. </html>

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部署好后打开login.jsp，输入任意非"YOYO"字符，控制台打印出

请求过滤

请求拦截

返回过滤

说明拦截之后还会按照原路返回；

如果输入"YOYO"，则打印出

请求过滤

请求拦截

登陆ACTION

返回拦截

返回过滤

由此可以验证它的执行顺序 = =。