SpringBoot+jpa简单的增删改查

1.application.yml

spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    username: root
    password: 123456
    url: jdbc:mysql://127.0.0.1:3306/lhr?characterEncoding=utf-8&useSSL=false
  jpa:
    show-sql: true
server:
  context-path: /demo

2.pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>com.lhr</groupId>
	<artifactId>demo</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<name>demo</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.5.10.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>

                <!--下面两个操作数据库-->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-jpa</artifactId>
		</dependency>

		<!--自动生成set get  等方法(idea需要装该插件)-->
		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>


</project>

3.dao层

User.java

package com.lhr.dataobject;

import lombok.Data;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

/**
 * Created by Administrator on 2018-02-24.
 */
@Entity
@Data
public class User {

    @Id
    @GeneratedValue
    private Integer id;

    private String name;

    private Integer age;
}

UserRepository.java

package com.lhr.repository;

import com.lhr.dataobject.User;
import org.springframework.data.jpa.repository.JpaRepository;

import java.util.List;

/**
 * Created by Administrator on 2018-02-24.
 */
public interface UserRepository extends JpaRepository<User,Integer>{

    //根据age查询
    public List<User> findAllByAge(Integer age);
}

4.service层

UserService.java

package com.lhr.service;

import com.lhr.dataobject.User;

import java.util.List;

/**
 * Created by Administrator on 2018-02-24.
 */
public interface UserService {

    //获取所有用户列表
    List<User> findAll();

    //新增,修改用户
    User save(User user);

    //根据id查询一个用户
    User findOne(Integer id);

    //根据ID删除一个用户
    void deleteOne(Integer id);

    //根据age查询用户
    List<User> findByAge(Integer age);
}

UserServiceImpl.java

package com.lhr.service.impl;

import com.lhr.dataobject.User;
import com.lhr.repository.UserRepository;
import com.lhr.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * Created by Administrator on 2018-02-24.
 */
@Service
public class UserServiceImpl implements UserService{

    @Autowired
    private UserRepository repository;

    @Override
    public User save(User user) {
        return repository.save(user);
    }

    @Override
    public List<User> findAll() {
        return repository.findAll();
    }

    @Override
    public User findOne(Integer id) {
        return repository.findOne(id);
    }

    @Override
    public void deleteOne(Integer id) {
        repository.delete(id);
    }

    @Override
    public List<User> findByAge(Integer age) {
        return repository.findAllByAge(age);
    }
}

5.controller层

UserController.java

package com.lhr.controller;

import com.lhr.dataobject.User;
import com.lhr.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

/**
 * Created by Administrator on 2018-02-24.
 */
@RestController
public class UserController {

    @Autowired
    private UserService userService;

    @GetMapping("/hello")
    public String login() {
        return "hello spring boot";
    }

    /**
     * 查询所有用户信息
     *
     * @return
     */
    @GetMapping("/userList")
    public List<User> getUserList() {
        return userService.findAll();
    }

    /**
     * 新增一个用户
     *
     * @param name
     * @param age
     * @return
     */
    @PostMapping("/add")
    public User addUser(@RequestParam("name") String name,
                        @RequestParam("age") Integer age) {
        User user = new User();
        user.setName(name);
        user.setAge(age);

        return userService.save(user);
    }


    /**
     * 根据ID查询用户
     *
     * @param id
     * @return
     */
    @GetMapping("/user/{id}")
    public User findUser(@PathVariable("id") Integer id) {
        return userService.findOne(id);
    }

    @PutMapping("/user/{id}")
    public User updateUser(@PathVariable("id") Integer id,
                           @RequestParam("name") String name,
                           @RequestParam("age") Integer age) {

        User user = new User();
        user.setId(id);
        user.setName(name);
        user.setAge(age);

        return userService.save(user);
    }

    /**
     * 根据ID删除用户
     *
     * @param id
     */
    @DeleteMapping("/user/{id}")
    public void deleteUser(@PathVariable("id") Integer id) {
        userService.deleteOne(id);
    }

    /**
     * 根据age查询用户
     *
     * @param age
     * @return
     */
    @GetMapping("/user/age/{age}")
    public List<User> findByAge(@PathVariable("age") Integer age) {
        return userService.findByAge(age);
    }
}