@RestController和@GetMapping

package com.exa.de.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @RestController注解，相当于@Controller+@ResponseBody两个注解的结合
 * 返回json数据不需要在方法前面加@ResponseBody注解了，但使用@RestController这个注解，就不能返回jsp,html页面，视图解析器无法解析jsp,html页面
 */
@RestController
@RequestMapping("rest")
public class RestFullController {
    @GetMapping("get")//url://http://localhost:8080/rest/get
    public String get(){
        return "我在这里";
    }

}

查询数据，没有带参数

@RestController
@RequestMapping("rest")
public class RestFullController {
    @GetMapping("get")//url://http://localhost:8080/rest/get
    public User get(){
        User user = new User(1,"lin","男",25);
        return user;
    }

}

 

package com.exa.de.entity;

public class User {
    int id;
    String name;
    String sex;
    int age;
//===Alt+Insert快捷键
    public User() {//无参
    }

    public User(int id, String name, String sex, int age) {//有参
        this.id = id;
        this.name = name;
        this.sex = sex;
        this.age = age;
    }



    public int getId() {//构造
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {//输出
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", sex='" + sex + '\'' +
                ", age=" + age +
                '}';
    }
}

查询数据，带来参数

    @GetMapping("{id}")//url://http://localhost:8080/rest/id(一个int类型)
    public User getById(@PathVariable("id")int id){//URL 中的 {xxx} 占位符可以通过@PathVariable(“xxx“) 绑定到操作方法的入参中。
        User user = new User(id,"huang","nv",18);
        System.out.println("getById user"+user);
        return user;
    }

    @PostMapping
    public User addUser(@RequestBody User user){//URL 中的 {xxx} 占位符可以通过@PathVariable(“xxx“) 绑定到操作方法的入参中。
        System.out.println(user);
        return user;
    }