/* /** #SpringMVC拦截器中/*和/**的区别 @FDDLC
问题：SpringMVC拦截器中/*和/**有什么区别？
咱们通过测试来得出结论。
首先，我写了5个拦截器：
补充：拦截器的配置示例：
然后，我又准备了5个请求路径：
@RequestMapping("/")
@RequestMapping("/one")
@RequestMapping("/one/two")
@RequestMapping("/one/two/three")
@RequestMapping("/one/two/three/four")
每个请求的方法里面都有对应的println语句，这里不展示。
最后，依次请求这5个路径，得到的控制台输出如下：
上面的结果表明了每个请求路径能触发哪些拦截器，而我们想知道的是每个拦截器能拦截哪些请求路径。所以需要对上面这些数据作一个处理：
从上面这个表格我们不难得出一些结论：
1、/* 能拦截 / 这个目录下的子女节点；/** 能拦截 / 这个目录下的所有后代节点。
2、/one/* 能拦截 /one 这个目录下的子女节点；/one/** 能拦截 /one 这个目录下的所有后代节点。
说明：
1、2其实是一回事，合起来说就是：
具体路径后面带一个*：能拦截这个具体路径的子女节点；
具体路径后面带两个*：能拦截这个具体路径的所有后代节点。
(看了很多国内的文章，也在*翻了一些问答，我的结论是可靠的哈~)
最后附上源码：
项目结构：
pom.xml的内容：
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.example</groupId>
<artifactId>P072_Interceptor_path</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<name>P072_Interceptor_path Maven Webapp</name>
<!-- FIXME change it to the project's website -->
<url>http://www.example.com</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.1.8.RELEASE</version>
</dependency>
<dependency>
<groupId>org.apache.tomcat</groupId>
<artifactId>servlet-api</artifactId>
<version>6.0.36</version>
</dependency>
</dependencies>
<build>
<finalName>P072_Interceptor_path</finalName>
<pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
<plugins>
<plugin>
<artifactId>maven-clean-plugin</artifactId>
<version>3.1.0</version>
</plugin>
<!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging -->
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>3.0.2</version>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.22.1</version>
</plugin>
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>3.2.2</version>
</plugin>
<plugin>
<artifactId>maven-install-plugin</artifactId>
<version>2.5.2</version>
</plugin>
<plugin>
<artifactId>maven-deploy-plugin</artifactId>
<version>2.8.2</version>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
web.xml的内容：
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<display-name>Archetype Created Web Application</display-name>
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!--关联springmvc.xml，让其中的配置生效！-->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
springmvc.xml的内容：
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
<context:component-scan base-package="cn.liuxingchang" />
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="viewResolver">
<property name="prefix" value="/WEB-INF/pages/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/"/>
<bean class="cn.liuxingchang.interceptor.MyInterceptor" />
</mvc:interceptor>
<mvc:interceptor>
<mvc:mapping path="/*"/>
<bean class="cn.liuxingchang.interceptor.MyInterceptor2" />
</mvc:interceptor>
<mvc:interceptor>
<mvc:mapping path="/**"/>
<bean class="cn.liuxingchang.interceptor.MyInterceptor3" />
</mvc:interceptor>
<mvc:interceptor>
<mvc:mapping path="/one/*"/>
<bean class="cn.liuxingchang.interceptor.MyInterceptor4" />
</mvc:interceptor>
<mvc:interceptor>
<mvc:mapping path="/one/**"/>
<bean class="cn.liuxingchang.interceptor.MyInterceptor5" />
</mvc:interceptor>
</mvc:interceptors>
</beans>
index.jsp的内容：
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <body> <a href="/">/</a><br /><br /> <a href="/one">/one</a><br /><br /> <a href="/one/two">/one/two</a><br /><br /> <a href="/one/two/three">/one/two/three</a><br /><br /> <a href="/one/two/three/four">/one/two/three/four</a><br /><br /> </body> </html>
！！！注意：因为上面的超链接我用的是绝对路径，所以访问项目的格式要设置成：http://localhost:[端口号]，比如http://localhost。不能是http://localhost/ssm这样的。
success.jsp的内容：
<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h3>success</h3>
</body>
</html>
MyInterceptor.java的内容：
package cn.liuxingchang.interceptor;
import org.springframework.web.servlet.HandlerInterceptor;
public class MyInterceptor implements HandlerInterceptor {
@Override
public boolean preHandle(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Object handler) throws Exception {
System.out.println("/");
return true;
}
}
MyInterceptor2.java的内容：
package cn.liuxingchang.interceptor;
import org.springframework.web.servlet.HandlerInterceptor;
public class MyInterceptor2 implements HandlerInterceptor {
@Override
public boolean preHandle(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Object handler) throws Exception {
System.out.println("/*");
return true;
}
}
MyInterceptor3.java的内容：
package cn.liuxingchang.interceptor;
import org.springframework.web.servlet.HandlerInterceptor;
public class MyInterceptor3 implements HandlerInterceptor {
@Override
public boolean preHandle(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Object handler) throws Exception {
System.out.println("/**");
return true;
}
}
MyInterceptor4.java的内容：
package cn.liuxingchang.interceptor;
import org.springframework.web.servlet.HandlerInterceptor;
public class MyInterceptor4 implements HandlerInterceptor {
@Override
public boolean preHandle(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Object handler) throws Exception {
System.out.println("/one/*");
return true;
}
}
MyInterceptor5.java的内容：
package cn.liuxingchang.interceptor;
import org.springframework.web.servlet.HandlerInterceptor;
public class MyInterceptor5 implements HandlerInterceptor {
@Override
public boolean preHandle(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, Object handler) throws Exception {
System.out.println("/one/**");
return true;
}
}
MyController.java的内容：
package cn.liuxingchang.controller;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
@Controller
public class MyController {
@RequestMapping("/")
public String test() {
System.out.println("request: /");
System.out.println("----------");
return "success";
}
@RequestMapping("/one")
public String test2() {
System.out.println("request: /one");
System.out.println("----------");
return "success";
}
@RequestMapping("/one/two")
public String test3() {
System.out.println("request: /one/two");
System.out.println("----------");
return "success";
}
@RequestMapping("/one/two/three")
public String test4() {
System.out.println("request: /one/two/three");
System.out.println("----------");
return "success";
}
@RequestMapping("/one/two/three/four")
public String test5() {
System.out.println("request: /one/two/three/four");
System.out.println("----------");
return "success";
}
}