定义包名后next->勾选基本依赖
finish 完成
删除application.properties,新建application.yml,配置信息如下:
spring:
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/jpa-demo?useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai
username: root
password: root
jpa:
hibernate:
ddl-auto: update
show-sql: true
com.mysql.jdbc.Driver
是 mysql5的jdbc驱动
com.mysql.cj.jdbc.Driver
是 mysql6的jdbc驱动需要注意的是com.mysql.cj.jdbc.Driver是要配置时区的,这里配置为 Asia/Shanghai
ddl-atuo取值
mysql新建数据库 jpa-demo
User.java
@Entity
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String nickname;
private String telnum;
@Temporal(TemporalType.TIMESTAMP)
private Date signDate;
//spring boot jpa 需要提供默认的构造函数
public User(){}
//此处省略get和set方法
}
@Entity
应用于实体类,表明该实体类被JPA管理,将映射到指定的数据库表
@Id
应用于实体类的属性或者属性对应的getter方法,表示该属性映射为数据库表的主键
@GerneratedValue
于@Id一同使用,表示主键的生成策略,通过strategy
属性指定。
JPA提供的生成策略有:
UserRepository.java
package com.wg.japdemo.domain;
import org.springframework.data.jpa.repository.JpaRepository;
public interface UserRepository extends JpaRepository<User,Long> {
}
UserService.java 定义了基本的增删改查接口
package com.wg.japdemo.service;
import com.wg.japdemo.domain.User;
import org.springframework.stereotype.Service;
public interface UserService {
User saveUser(User user);
void deleteUser(User user);
void deleteUser(Long id);
User updateUser(User user);
User findUser(Long id);
}
UserServiceImpl.java UserService接口实现类
package com.wg.japdemo.service;
import com.wg.japdemo.domain.User;
import com.wg.japdemo.domain.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
/**
* @Author: wanggang.io
* @Date: 2018/12/13 8:56
* @todo
*/
@Service
public class UserServiceImpl implements UserService {
@Autowired
private UserRepository userRepository;
@Override
public User saveUser(User user) {
User user1 = userRepository.save(user);
return user1;
}
@Override
public void deleteUser(User user) {
userRepository.delete(user);
}
@Override
public void deleteUser(Long id) {
userRepository.deleteById(id);
}
@Override
public User updateUser(User user) {
return userRepository.save(user);
}
@Override
public User findUser(Long id) {
return userRepository.findById(id).get();
}
}
UserController.java
package com.wg.japdemo.controller;
import com.wg.japdemo.domain.User;
import com.wg.japdemo.domain.Wallet;
import com.wg.japdemo.service.UserServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.math.BigDecimal;
import java.util.Date;
/**
* @Author: wanggang.io
* @Date: 2018/12/13 9:03
* @todo
*/
@RestController
@RequestMapping("user")
public class UserController {
@Autowired
private UserServiceImpl userServiceImpl;
@GetMapping("add")
private User addUser(String nickName,String telNum){
User user = new User();
user.setNickname(nickName);
user.setTelnum(telNum);
userServiceImpl.saveUser(user);
return user;
}
@GetMapping("del")
private String delUser(Long id){
userServiceImpl.deleteUser(id);
return "SUCCESS";
}
@GetMapping("update")
private User updateUser(Long id,String nickName){
User user = userServiceImpl.findUser(id);
user.setNickname(nickName);
userServiceImpl.updateUser(user);
return user;
}
@GetMapping("find")
private User findUser(Long id){
return userServiceImpl.findUser(id);
}
}
好了,是时候运行程序验证下我们的成果了
首次执行程序时,jpa会根据User类在数据库中自动生成表
通过log打印的sql,可以看到执行了建表操作
Hibernate: create table user (id bigint not null auto_increment, nickname varchar(255), sign_date datetime, telnum varchar(255)) engine=MyISAM
打开chrom浏览器,依次访问下面链接 ,我本机的8080端口被占用了,这里使用的时9191
新增
http://localhost:9191/user/add?nickName=Jack&telNum=13848484848
新建User用户 nickName为jack,telNum为:13848484848
修改
http://localhost:9191/user/update?nickName=Tom&id=1
将Id为1的用户nickName修改为Tom
删除
http://localhost:9191/user/del?id=1
删除Id为1的用户
查询
http://localhost:9191/user/find?id=2
查询Id为2的用户
项目地址