RequestMapping专题

1、springMVC使用@RequestMapping注解为控制器指定可以处理哪些URL请求

DispatcherServlet截获请求后就通过控制器上@RequestMapping提供的映射信息确定请求所对应的处理方法
@RequestMapping不仅可以修饰方法还可以修饰类

1）类定义处：提供初步的请求映射信息，相对于web应用的根目录

2）方法定义处：提供进一步的细分映射信息，相对于类定义处的URL,若类定义处未标记@RequestMapping，则方法标记的URL相对于WEB应用的根目录

1）修饰方法

 1 package com.atguigu.springmvc.handlers;
 2 
 3 import org.springframework.stereotype.Controller;
 4 import org.springframework.web.bind.annotation.RequestMapping;
 5 
 6 @Controller //这样标识后HelloWorld成为控制器，在springmvc叫做handler处理器或请求处理器
 7 public class HelloWorld {
 8     /**
 9      * 1、使用@RequestMapping注解来映射请求的URL
10      * 2、返回值会通过视图解析器解析为实际的物理视图:对于InternalResourceViewResolver视图解析器，会做如下解析：
11      *    通过prefix+returnvel+后缀这样的方式得到实际的物理视图，然后转发
12      *    /WEB-INF/views/success.jsp
13      * @return
14      */
15     @RequestMapping("/helloworld")//映射请求
16     public String hello() {
17         System.out.println("HelloWorld");
18         return "success";
19     }
20 }

实现代码同HelloWorld实例。

2）修饰类

 1 package com.atguigu.springmvc.handlers;
 2 
 3 import org.springframework.stereotype.Controller;
 4 import org.springframework.web.bind.annotation.RequestMapping;
 5 
 6 @RequestMapping("/springmvc")
 7 @Controller
 8 public class SpringMVCTest {
 9     private static final String SUCCESS = "success";
10 
11     @RequestMapping("/testRequestMapping")
12     public String testRequestMapping() {
13         System.out.println("testRequestMapping");
14         return SUCCESS;
15     }
16 }

3)index.xml改为

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 4 <html>
 5 <head>
 6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 7 <title>Insert title here</title>
 8 </head>
 9 <body>
10     <!-- 超链接 -->
11     <a href="/springmvc/testRequestMapping">TestRequestMapping</a>
12     <!--  <br><br> <a href="/helloworld">HelloWorld</a>  -->
13 </body>
14 </html>

2、 RequestMapping的请求方式(联合多个条件可以让请求映射更加精确化)

请求URL：value

请求方法:method

请求参数:params(了解)

请求头:heads（了解）

举例：method(常用)

 1 package com.atguigu.springmvc.handlers;
 2 
 3 import org.springframework.stereotype.Controller;
 4 import org.springframework.web.bind.annotation.RequestMapping;
 5 import org.springframework.web.bind.annotation.RequestMethod;
 6 
 7 @RequestMapping("/springmvc")
 8 @Controller
 9 public class SpringMVCTest {
10     private static final String SUCCESS = "success";
11 /**
12  * 使用method属性来指定请求方式
13  */
14     @RequestMapping(value="/testMethod",method=RequestMethod.POST)
15     public String testMethod(){
16         System.out.println("testMethod");
17         return SUCCESS;
18     }
19 }

index.jsp

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 4 <html>
 5 <head>
 6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 7 <title>Insert title here</title>
 8 </head>
 9 <body>
10     <!-- 超链接 -->
11     <form action="springmvc/testMethod" method="POST"> <input
12         type="submit" value="submit"></form>
13      <a href="springmvc/testMethod">TestMethod</a> 
14     <!-- <br><br> <a href="/helloworld">HelloWorld</a>  -->
15 </body>
16 </html>

举例params

 1 package com.atguigu.springmvc.handlers;
 2 
 3 import org.springframework.stereotype.Controller;
 4 import org.springframework.web.bind.annotation.RequestMapping;
 5 import org.springframework.web.bind.annotation.RequestMethod;
 6 
 7 @RequestMapping("/springmvc")
 8 @Controller
 9 public class SpringMVCTest {
10     private static final String SUCCESS = "success";
11     /**
12      * 了解：可以使用params和headers来更加精确的映射请求，params和headers支持简单的表达式
13      */
14     @RequestMapping(value="testParamsAndHeaders",
15             params={"username","age!=10"})
16     public String testParamsAndHeaders(){
17         System.out.println("testParamsAndHeaders");
18         return SUCCESS;
19     }
20 }

index.jsp文件

 1 <%@ page language="java" contentType="text/html; charset=UTF-8"
 2     pageEncoding="UTF-8"%>
 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 4 <html>
 5 <head>
 6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 7 <title>Insert title here</title>
 8 </head>
 9 <body>
10     <!-- 超链接 -->
11 
12     <a href="springmvc/testParamsAndHeaders?username=atguigu&age=10">Test ParamsAndHeaders</a>
13 </body>
14 </html>

举例headers

 1 package com.atguigu.springmvc.handlers;
 2 
 3 import org.springframework.stereotype.Controller;
 4 import org.springframework.web.bind.annotation.RequestMapping;
 5 import org.springframework.web.bind.annotation.RequestMethod;
 6 
 7 @RequestMapping("/springmvc")
 8 @Controller
 9 public class SpringMVCTest {
10     private static final String SUCCESS = "success";
11     /**
12      * 了解：可以使用params和headers来更加精确的映射请求，params和headers支持简单的表达式
13      */
14     @RequestMapping(value="testParamsAndHeaders",
15             params={"username","age!=10"},headers={"Accept-Language=zh-CN,zh;q=0.8"})
16     public String testParamsAndHeaders(){
17         System.out.println("testParamsAndHeaders");
18         return SUCCESS;
19     }
20 }

index.jsp与上述相同

3、@RequestMapping映射请求支持Ant风格资源地址3中匹配符：(了解)

？：匹配文件名中的一个字符
* ：匹配文件名中的任意字符
**：**匹配多层路径

1 @RequestMapping("/springmvc")
2 @Controller
3 public class SpringMVCTest {
4     private static final String SUCCESS = "success";
5     @RequestMapping("/testAntPath/*/abc")
6     public String testAntPath(){
7         System.out.println("testAntPath");
8         return SUCCESS;
9     }