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

package com.example.demo.controller;

import org.springframework.web.bind.annotation.*;

@RestController
// 该类下的所有方法加统一前缀
// @RequestMapping("/prefix")
public class ParaController {

    // http://localhost:8080/firstRequest
    @GetMapping({"/firstRequest"})
     public String firstRequest(){
         return "第一个接口.";
     }


     // http://localhost:8080/requestPara?num=34
     @GetMapping({"/requestPara"})
     public String requestPara(@RequestParam Integer num){
        return "para from request: " + num;
     }


    // http://localhost:8080/para/6
    @GetMapping({"/para/{num}"})
    public String pathPara(@PathVariable Integer num){
        return "para from path: " + num;
    }


    // 多url
    // http://localhost:8080/para1/9
    // http://localhost:8080/para2/9
    @GetMapping({"/para1/{num}", "/para2/{num}"})
    public String multiUrl(@PathVariable Integer num){
        return "para from path: " + num;
    }


    // 参数设默认值
    // http://localhost:8080/required
    // http://localhost:8080/required?num=5
    @GetMapping({"/required"})
    public String required(@RequestParam(required = false, defaultValue = "0") Integer num){
        return "para from request: " + num;
    }

}

方法分析：

最简单的实现：

http://localhost:8080/firstRequest

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

路径中带参数：

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

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

路径中带参数：

http://localhost:8080/para/6

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

多url：

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

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

参数设默认值：

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

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