springboot注解及GET、POST接口写法

一、注解
springboot提供了@Contrller和@RestController。

@Controller：返回页面和数据

@RestController：返回数据

@RestMapping注解：主要做路径映射url

value：请求URL的路径。

method：HTTP请求方法。

@RestMapping(value="user", method= RequestMethod.GET)

1.1 GET

• 无参数

@RequestMapping (value="/hello", method= RequestMethod.GET)
    public String hello(String name){
        return "123"+name;
    }

• 参数传递

@RequestMapping (value="/hello", method= RequestMethod.GET)
    public String hello(String name){
        return "123"+name;
    }

• 参数映射

@RequestParam注解代表参数映射，将传入进来的nickname映射到name

@RequestMapping (value="/hello2", method= RequestMethod.GET)
    public String hello2(@RequestParam(value ="nickname",required = false) String name){
        return "123"+name;
    }

1.2 POST

• 无参数

@RequestMapping(value = "/post1", method = RequestMethod.POST)
    public String post1(){
        return "hello post";
    }

• 带参数

@RequestMapping(value = "/post2", method = RequestMethod.POST)
    public String post2(String username, String password){
        return username+"-"+password;
    }

• Bean封装

@RequestMapping(value = "/post3",method = RequestMethod.POST)
    public String post3(User user){
        System.out.println(user);
        return "post";
    }

• json

要在参数前面加一个注解@RequestBody,传入进来的参数名和类的私有变量要保持一致

@RequestMapping(value = "/post34",method = RequestMethod.POST)
    public String post4(@RequestBody User user){
        System.out.println(user);
        return "post";
    }

1.3错误

• 404 ：路劲不对
• 405：方法不被允许