org.springframework.web.HttpMediaTypeNotSupportedException：不支持内容类型'application / json'

Question

当我在控制器类中使用@RequestBody时，出现异常。

@RequestMapping(method=RequestMethod.PUT, value = "/account",consumes = MediaType.APPLICATION_JSON_VALUE, produces = MediaType.APPLICATION_JSON_VALUE)
        public String signup1( @RequestBody Login login) {
            System.out.println("SignupController called");
        //  SignupImpl obj = new SignupImpl();
            return login;
        }

java上过课程

public class Login {
    String username;
    String password;
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
}

JSOn请求

{  
  "username":"mkyong",
  "password":"abc"
}