SpringBoot（四）-- 整合Servlet、Filter、Listener

SpringBoot中有两种方式可以添加 Servlet、Filter、Listener。

1.代码注册

　通过ServletRegistrationBean、 FilterRegistrationBean 和 ServletListenerRegistrationBean 获得控制。

新建WebConfig 类，用于bean的注入，内容如下：

 1 package com.xsjt.config;
 2 
 3 import java.util.ArrayList;
 4 import java.util.EventListener;
 5 import java.util.List;
 6 import org.springframework.boot.web.servlet.FilterRegistrationBean;
 7 import org.springframework.boot.web.servlet.ServletListenerRegistrationBean;
 8 import org.springframework.boot.web.servlet.ServletRegistrationBean;
 9 import org.springframework.context.annotation.Bean;
10 import org.springframework.context.annotation.Configuration;
11 import com.xsjt.filter.XbqFilter;
12 import com.xsjt.listener.XbqListener;
13 import com.xsjt.servlet.XbqServlet;
14 
15 /**  
16  * ClassName:WebConfig 
17  * 通过 @bean 注入 servlet、filter、listener
18  * Date:     2017年11月6日 下午6:10:30
19  * @author   Joe  
20  * @version    
21  * @since    JDK 1.8
22  */
23 @Configuration
24 public class WebConfig {
25 
26     /**
27      * servletRegistrationBean:(使用代码注册Servlet（不需要@ServletComponentScan注解）). 
28      * @author Joe
29      * Date:2017年11月6日下午6:13:29
30      *
31      * @return
32      */
33     @Bean
34     public ServletRegistrationBean servletRegistrationBean(){
35         ServletRegistrationBean registrationBean = new ServletRegistrationBean();
36         registrationBean.setServlet(new XbqServlet());
37         List<String> urlMappings = new ArrayList<String>();
38         // 访问，可以添加多个
39         urlMappings.add("/xbq/servlet");
40         registrationBean.setUrlMappings(urlMappings);
41         registrationBean.setLoadOnStartup(1);
42         return registrationBean;
43     }
44     
45     /**
46      * getDemoFilter:(使用代码注册拦截器).  
47      * @author Joe
48      * Date:2017年11月6日下午6:17:31
49      *
50      * @return
51      */
52     @Bean
53     public FilterRegistrationBean getDemoFilter(){
54         XbqFilter demoFilter = new XbqFilter();
55         FilterRegistrationBean registrationBean=new FilterRegistrationBean();
56         registrationBean.setFilter(demoFilter);
57         List<String> urlPatterns=new ArrayList<String>();
58         urlPatterns.add("/*");                            //拦截路径，可以添加多个
59         registrationBean.setUrlPatterns(urlPatterns);
60         registrationBean.setOrder(1);
61         return registrationBean;
62     }
63     
64     /**
65      * getDemoListener:(使用代码 引用 监听器).  
66      * @author Joe
67      * Date:2017年11月6日下午6:35:28
68      *
69      * @return
70      */
71     @Bean
72     public ServletListenerRegistrationBean<EventListener> getDemoListener(){
73         ServletListenerRegistrationBean<EventListener> registrationBean = new ServletListenerRegistrationBean<>();
74         registrationBean.setListener(new XbqListener());
75         registrationBean.setOrder(1);
76         return registrationBean;
77     }
78 }

其中，代码中 XbqServlet 、XbqFilter、XbqListener 代码如下：

 1 package com.xsjt.servlet;
 2 
 3 import java.io.IOException;
 4 import java.io.PrintWriter;
 5 import javax.servlet.ServletException;
 6 import javax.servlet.http.HttpServlet;
 7 import javax.servlet.http.HttpServletRequest;
 8 import javax.servlet.http.HttpServletResponse;
 9 
10 /**  
11  * ClassName:XbqServlet 
12  * 通过 代码注册Servlet 
13  * Date:     2017年11月6日 下午5:13:10
14  * @author   Joe  
15  * @version    
16  * @since    JDK 1.8
17  */
18 public class XbqServlet extends HttpServlet{
19 
20     private static final long serialVersionUID = 1L;
21 
22     @Override
23     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
24         this.doPost(req, resp);
25     }
26 
27     @Override
28     protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
29         resp.setCharacterEncoding("UTF-8");
30         resp.setContentType("text/html");  
31         PrintWriter out = resp.getWriter();  
32         out.println("<html>");  
33         out.println("<head>");  
34         out.println("<title>Hello World</title>");  
35         out.println("</head>");  
36         out.println("<body><center>");  
37         out.println("<h3>我是通过代码注册Servlet</h3>");  
38         out.println("</center></body>");  
39         out.println("</html>"); 
40     }
41 }

View Code

 1 package com.xsjt.filter;
 2 
 3 import java.io.IOException;
 4 
 5 import javax.servlet.Filter;
 6 import javax.servlet.FilterChain;
 7 import javax.servlet.FilterConfig;
 8 import javax.servlet.ServletException;
 9 import javax.servlet.ServletRequest;
10 import javax.servlet.ServletResponse;
11 import javax.servlet.http.HttpServletRequest;
12 import org.slf4j.Logger;
13 import org.slf4j.LoggerFactory;
14 
15 /**  
16  * ClassName:JoeFilter 
17  * 自定义 Serlvlet 的过滤器 
18  * Date:     2017年11月6日 下午6:01:33
19  * @author   Joe  
20  * @version    
21  * @since    JDK 1.8
22  */
23 public class XbqFilter implements Filter {
24     
25     private static Logger logger = LoggerFactory.getLogger(XbqFilter.class);
26 
27     @Override
28     public void init(FilterConfig filterConfig) throws ServletException {
29         logger.info("--xbq--初始化JoeFilter!");
30     }
31 
32     @Override
33     public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
34         HttpServletRequest req = (HttpServletRequest)request;
35         logger.info(req.getRequestURL() + "---xbq---> doFilter ");
36         chain.doFilter(request, response);
37     }
38 
39     @Override
40     public void destroy() {
41         logger.info("--xbq--销毁JoeFilter!");
42     }
43 
44 }

View Code

 1 package com.xsjt.listener;
 2 
 3 import javax.servlet.ServletContextEvent;
 4 import javax.servlet.ServletContextListener;
 5 
 6 import org.slf4j.Logger;
 7 import org.slf4j.LoggerFactory;
 8 
 9 /**  
10  * ClassName:JoeListener 
11  * Date:     2017年11月6日 下午6:28:29
12  * @author   Joe  
13  * @version    
14  * @since    JDK 1.8
15  */
16 public class XbqListener implements ServletContextListener{
17     
18     private static Logger logger = LoggerFactory.getLogger(XbqListener.class);
19 
20     @Override
21     public void contextInitialized(ServletContextEvent sce) {
22         logger.info("--xbq-监听器-ServletContext 初始化");
23         logger.info(sce.getServletContext().getServerInfo());
24     }
25 
26     @Override
27     public void contextDestroyed(ServletContextEvent sce) {
28         logger.info("--xbq-监听器-ServletContext 销毁");
29     }
30 }

View Code

2.通过注解自动注册

在 SpringBootApplication 上使用@ServletComponentScan 注解后，Servlet、Filter、Listener 可以直接通过 @WebServlet(urlPatterns = "/test/*")、@WebFilter、@WebListener 注解自动注册,这些注解都是JDK的，无需其他代码。

1) Servlet

 1 package com.xsjt.servlet;
 2 
 3 import java.io.IOException;
 4 import java.io.PrintWriter;
 5 import javax.servlet.ServletException;
 6 import javax.servlet.annotation.WebServlet;
 7 import javax.servlet.http.HttpServlet;
 8 import javax.servlet.http.HttpServletRequest;
 9 import javax.servlet.http.HttpServletResponse;
10 
11 /**  
12  * ClassName:XbqServlet 
13  * 通过  @WebServlet 注解 整合Servlet
14  * Date:     2017年11月6日 下午5:13:10
15  * @author   Joe  
16  * @version    
17  * @since    JDK 1.8
18  */
19 @WebServlet(urlPatterns = "/joe/*")
20 public class JoeServlet extends HttpServlet{
21 
22     private static final long serialVersionUID = 1L;
23 
24     @Override
25     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
26         this.doPost(req, resp);
27     }
28 
29     @Override
30     protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
31         resp.setCharacterEncoding("UTF-8");
32         resp.setContentType("text/html");  
33         PrintWriter out = resp.getWriter();  
34         out.println("<html>");  
35         out.println("<head>");  
36         out.println("<title>Hello World</title>");  
37         out.println("</head>");  
38         out.println("<body><center>");  
39         out.println("<h3>我是通过   @WebServlet 注解注册Servlet的</h3>");  
40         out.println("</center></body>");  
41         out.println("</html>"); 
42     }
43 }

2) Filter

 1 package com.xsjt.filter;
 2 
 3 import java.io.IOException;
 4 import javax.servlet.Filter;
 5 import javax.servlet.FilterChain;
 6 import javax.servlet.FilterConfig;
 7 import javax.servlet.ServletException;
 8 import javax.servlet.ServletRequest;
 9 import javax.servlet.ServletResponse;
10 import javax.servlet.annotation.WebFilter;
11 import javax.servlet.http.HttpServletRequest;
12 import org.slf4j.Logger;
13 import org.slf4j.LoggerFactory;
14 import org.springframework.core.annotation.Order;
15 
16 /**  
17  * ClassName:JoeFilter 
18  * 自定义  Filter
19  *         @Order注解表示执行过滤顺序，值越小，越先执行
20  * Date:     2017年11月6日 下午6:01:33
21  * @author   Joe  
22  * @version    
23  * @since    JDK 1.8
24  */
25 @Order(1)
26 @WebFilter(filterName = "joeFilter", urlPatterns = "/*")
27 public class JoeFilter implements Filter {
28     
29     private static Logger logger = LoggerFactory.getLogger(JoeFilter.class);
30 
31     @Override
32     public void init(FilterConfig filterConfig) throws ServletException {
33         logger.info("--joe--初始化JoeFilter!");
34     }
35 
36     @Override
37     public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
38         HttpServletRequest req = (HttpServletRequest)request;
39         logger.info(req.getRequestURL() + "---joe---> doFilter");
40         chain.doFilter(request, response);
41     }
42 
43     @Override
44     public void destroy() {
45         logger.info("--joe--销毁JoeFilter!");
46     }
47 }

3) Listener

 1 package com.xsjt.listener;
 2 
 3 import javax.servlet.ServletContextEvent;
 4 import javax.servlet.ServletContextListener;
 5 import javax.servlet.annotation.WebListener;
 6 import org.slf4j.Logger;
 7 import org.slf4j.LoggerFactory;
 8 
 9 /**  
10  * ClassName:JoeListener 
11  * Date:     2017年11月6日 下午6:28:29
12  * @author   Joe  
13  * @version    
14  * @since    JDK 1.8
15  */
16 @WebListener
17 public class JoeListener implements ServletContextListener{
18     
19     private static Logger logger = LoggerFactory.getLogger(JoeListener.class);
20 
21     @Override
22     public void contextInitialized(ServletContextEvent sce) {
23         logger.info("--Joe-监听器-ServletContext 初始化");
24         logger.info(sce.getServletContext().getServerInfo());
25     }
26 
27     @Override
28     public void contextDestroyed(ServletContextEvent sce) {
29         logger.info("--Joe-监听器-ServletContext 销毁");
30     }
31 }

3.源码下载

　　https://gitee.com/xbq168/spring-boot-learn

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原文地址：https://www.cnblogs.com/xbq8080/p/7768916.html