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springmvc注解

2024-08-20 09:05:50   223人阅读

1、@RequestParam（重要）：映射请求参数

1 @RequestMapping("/springmvc")
2 @Controller
3 public class SpringMVCTest {
4     private static final String SUCCESS = "success";
5 @RequestMapping("/testRequestParam")
6     public String testRequestParam(@RequestParam(value = "http://www.mamicode.com/username") String un, @RequestParam(value = "http://www.mamicode.com/age") int age) {
7         System.out.println("testRequestParam,username:" + un + ",age:" + age);
8         return SUCCESS;
9     }

若请求参数age不是必须的，那么代码可以改为：

 1 @RequestMapping("/springmvc")
 2 @Controller
 3 public class SpringMVCTest {
 4     private static final String SUCCESS = "success";
 5 
 6     /*
 7      * @RequestParam来映射请求参数 value值即为请求参数的参数名 required：确定该参数是否必须，默认为true
 8      * defaultValue 请求参数的默认值
 9      */
10     @RequestMapping("/testRequestParam")
11     public String testRequestParam(@RequestParam(value = "http://www.mamicode.com/username") String un, 
12             @RequestParam(value = "http://www.mamicode.com/age",required=false,defaultValue="http://www.mamicode.com/0") int age) {
13         System.out.println("testRequestParam,username:" + un + ",age:" + age);
14         return SUCCESS;
15     }

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     <a href="springmvc/testRequestParam?username=atguigu&age=11">Test RequestParam</a>

整体效果实现的其他代码参见HelloWorld实例。

 2、@RequestHeader：映射请求头信息

1 @RequestMapping("/springmvc")
2 @Controller
3 public class SpringMVCTest {
4     private static final String SUCCESS = "success";
5     @RequestMapping("/testRequestHeader")
6     public String testRequestHeader(@RequestHeader(value="http://www.mamicode.com/Accept-Language")String rl){
7         System.out.println("testRequestHeader,Accept-Language:"+rl);
8         return SUCCESS;
9     }

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     <a href="springmvc/testRequestHeader">Test RequestHeader</a>
12     </body>
13 </html>

整体效果实现的其他代码参见HelloWorld实例。

下面例子两个注解都有用到，供参考：

 1 package com.atguigu.springmvc.handlers;
 2 
 3 import org.springframework.stereotype.Controller;
 4 import org.springframework.web.bind.annotation.RequestHeader;
 5 import org.springframework.web.bind.annotation.RequestMapping;
 6 import org.springframework.web.bind.annotation.RequestMethod;
 7 import org.springframework.web.bind.annotation.RequestParam;
 8 
 9 @RequestMapping("/springmvc")
10 @Controller
11 public class SpringMVCTest {
12     private static final String SUCCESS = "success";
13     /**
14      * 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
15      */
16     @RequestMapping(value="http://www.mamicode.com/testParamsAndHeaders",
17             params={"usernamexxxxx","age!=10"},headers={"Accept-Language=zh-CN,zh;q=0.8"})
18     public String testParamsAndHeaders(){
19         System.out.println("testParamsAndHeaders");
20         return SUCCESS;
21     }
22     
23     @RequestMapping(value="http://www.mamicode.com/testParamsAndHeaders2")
24     public String testParamsAndHeaders2(@RequestParam("usernamex") String username, @RequestHeader("Host") String host){
25         System.out.println(username + "-->" + host);
26         return SUCCESS;
27     }
28 }

 3、@PathVariable

可以将URL中占位符参数绑定到控制器处理方法的入参中，例如：

 1 @RequestMapping("/springmvc")
 2 @Controller
 3 public class SpringMVCTest {
 4     private static final String SUCCESS = "success";
 5     /**
 6      * @PathVariable可以映射URL中的占位符到目标方法的参数中
 7      */
 8     @RequestMapping("/testPathVariable/{id}")
 9     public String testPathVariable(@PathVariable("id") Integer id) {
10         System.out.println("testPathVariable:" + id);
11         return SUCCESS;
12     }

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     <a href="springmvc/testPathVariable/1">Test PathVariable</a>
12 </body>
13 </html>

4、@RequestBody (用的很少)

1 @RequestMapping(value = "http://www.mamicode.com/something", method = RequestMethod.PUT)
2 public void handle(@RequestBody String body, Writer writer) throws IOException {
3   writer.write(body);
4 }

整体效果实现的其他代码参见HelloWorld实例。

总结：            @PathVariabl                       Path                 http://localhost:8080/third-ssmm/springmvc/testPathVariable/1   （全路径）

 springMVC    @RequestHeader http几种域：header      eg:  http://localhost:8080/third-ssmm/springmvc/testRequestHeader

                    @RequestParam                    Query              http://localhost:8080/third-ssmm/springmvc/testRequestParam?username=atguigu&age=11

                    @RequestBody                      Body                   （?前面是路径？后面是访问参数 ）      

 

springmvc注解


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