SpringBoot Controller接收参数的几种经常使用方式

第一类：请求路径参数

一、@PathVariable

获取路径参数。即url/{id}这种形式。

二、@RequestParam

获取查询参数。即url?name=这种形式

例子

GET 

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

对应的java代码：

@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);
}

也能够设置默认

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

输出结果： 
id=123 
name=suki_rong

第二类：Body参数

由于是POST请求，这里用Postman的截图结合代码说明

一、@RequestBody

例子

对应的java代码：

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

输出结果： 
name:suki_rong;age=18;hobby:programing

也能够是这样

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

输出结果： 
suki_rong

二、无注解

例子

对应的java代码：

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

输出结果： 
name:suki_rong;age=18;hobby:programing

Person类

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
}

第三类：请求头参数以及Cookie

一、@RequestHeader

二、@CookieValue

例子

java代码：

@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);
}

也能够这样

@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());
        }
    }
}