SpringBoot Controller接收參數的幾種常用方式

第一類：請求路徑參數

1、@PathVariable

獲取路徑參數。即url/{id}這種形式。

2、@RequestParam

獲取查詢參數。即url?name=這種形式

例子

GET 

http://localhost:8080/demo/123?name=suki_rong 

對應的java代碼：

@GetMapping("/demo/{id}")
public void demo(@PathVariable(name = "id") String id, @RequestParam(name = "name") String name) {
    System.out.println("id="+id);
    System.out.println("name="+name);
}

也可以設置默認

public  String say(@PathVariable("id") Integer id, @RequestParam( value = "name", required = false, defaultValue = "0") String name){
        return "id =" + id + ";name = " + name;
    }

輸出結果： 
id=123 
name=suki_rong

第二類：Body參數

因為是POST請求，這里用Postman的截圖結合代碼說明

1、@RequestBody

例子

對應的java代碼：

@PostMapping(path = "/demo1")
public void demo1(@RequestBody Person person) {
    System.out.println(person.toString());
}

輸出結果： 
name:suki_rong;age=18;hobby:programing

也可以是這樣

@PostMapping(path = "/demo1")
public void demo1(@RequestBody Map<String, String> person) {
    System.out.println(person.get("name"));
}

輸出結果： 
suki_rong

2、無注解

例子

對應的java代碼：

@PostMapping(path = "/demo2")
public void demo2(Person person) {
    System.out.println(person.toString());
}

輸出結果： 
name:suki_rong;age=18;hobby:programing

Person類

public class Person {

    private long id;
    private String name;
    private int age;
    private String hobby;

    @Override
    public String toString(){
        return "name:"+name+";age="+age+";hobby:"+hobby;
    }

    // getters and setters
}

第三類：請求頭參數以及Cookie

1、@RequestHeader

2、@CookieValue

例子

java代碼：

@GetMapping("/demo3")
public void demo3(@RequestHeader(name = "myHeader") String myHeader,
        @CookieValue(name = "myCookie") String myCookie) {
    System.out.println("myHeader=" + myHeader);
    System.out.println("myCookie=" + myCookie);
}

也可以這樣

@GetMapping("/demo3")
public void demo3(HttpServletRequest request) {
    System.out.println(request.getHeader("myHeader"));
    for (Cookie cookie : request.getCookies()) {
        if ("myCookie".equals(cookie.getName())) {
            System.out.println(cookie.getValue());
        }
    }
}