controller 方法路径、参数的使用

创建项目：

　　IDEA新建springboot项目；

　　如图所示建包和类；

项目结构：

关键代码：

ParaController.java

 1 package com.example.demo.controller;
 2 
 3 import org.springframework.web.bind.annotation.*;
 4 
 5 @RestController
 6 // 该类下的所有方法加统一前缀
 7 // @RequestMapping("/prefix")
 8 public class ParaController {
 9 
10     // http://localhost:8080/firstRequest
11     @GetMapping({"/firstRequest"})
12      public String firstRequest(){
13          return "第一个接口.";
14      }
15 
16 
17      // http://localhost:8080/requestPara?num=34
18      @GetMapping({"/requestPara"})
19      public String requestPara(@RequestParam Integer num){
20         return "para from request: " + num;
21      }
22 
23 
24     // http://localhost:8080/para/6
25     @GetMapping({"/para/{num}"})
26     public String pathPara(@PathVariable Integer num){
27         return "para from path: " + num;
28     }
29 
30 
31     // 多url
32     // http://localhost:8080/para1/9
33     // http://localhost:8080/para2/9
34     @GetMapping({"/para1/{num}", "/para2/{num}"})
35     public String multiUrl(@PathVariable Integer num){
36         return "para from path: " + num;
37     }
38 
39 
40     // 参数设默认值
41     // http://localhost:8080/required
42     // http://localhost:8080/required?num=5
43     @GetMapping({"/required"})
44     public String required(@RequestParam(required = false, defaultValue = "0") Integer num){
45         return "para from request: " + num;
46     }
47 
48 }

View Code

方法分析：

最简单的实现：

http://localhost:8080/firstRequest

1 　　  @GetMapping({"/firstRequest"})
2      public String firstRequest(){
3          return "第一个接口.";
4      }

路径中带参数：

http://localhost:8080/requestPara?num=34

1 　　  @GetMapping({"/requestPara"})
2      public String requestPara(@RequestParam Integer num){
3         return "para from request: " + num;
4      }

路径中带参数：

http://localhost:8080/para/6

1 　　 @GetMapping({"/para/{num}"})
2     public String pathPara(@PathVariable Integer num){
3         return "para from path: " + num;
4     }

多url：

http://localhost:8080/para1/9
http://localhost:8080/para2/9

1  　　@GetMapping({"/para1/{num}", "/para2/{num}"})
2     public String multiUrl(@PathVariable Integer num){
3         return "para from path: " + num;
4     }

参数设默认值：

http://localhost:8080/required
http://localhost:8080/required?num=5

1 　　@GetMapping({"/required"})
2     public String required(@RequestParam(required = false, defaultValue = "0") Integer num){
3         return "para from request: " + num;
4     }