spring boot——集成JPA——入门示例001

需要新增的依赖：

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>

<dependency>
   <groupId>mysql</groupId>
   <artifactId>mysql-connector-java</artifactId>
   <scope>runtime</scope>
</dependency>

pom文件如下：

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.mohai.one</groupId>
    <artifactId>springboot-data-jpa</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot-data-jpa</name>
    <description>spring-data-jpa整合实现</description>
 
    <properties>
        <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-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
 
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
 
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>
 
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
 
</project>

application.yml配置信息：

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/mohai_demo?useUnicode=true&characterEncoding=UTF-8&autoReconnect=true&useSSL=true&serverTimezone=Asia/Shanghai&zeroDateTimeBehavior=convertToNull
    username: root
    password: 123456
 
  # JPA配置
  jpa:
    # 数据库类型
    database: mysql
    # 切换默认的存储引擎切换为InnoDB
    database-platform: org.hibernate.dialect.MySQL5InnoDBDialect
    # 输出日志中打印出执行的SQL语句
    show-sql: true
    # 配置程序在启动的时候自动操作实体类对应的表
    hibernate:
      #create：程序重新启动时，都会重新创建表，会造成数据会丢失
      #create-drop：每次运行程序时，会先创建表结构，然后待程序结束时清空表
      #upadte：每次运行程序时，实体对应没有表时会创建表，如果实体发生改变会更新表结构，原来数据不会清空只会更新
      #validate：每次运行程序时，会校验数据与数据库的字段类型是否相同
      ddl-auto: update

UserEntity类

package com.mohai.one.springbootjpa.domain;

import javax.persistence.*;

@Entity //必选注解，声明和数据库中user表关联
@Table(name = "user") //可选注解，声明实体对应的表信息
public class UserEntity {

    @Id // 表名实体唯一标识
    @GeneratedValue(strategy = GenerationType.IDENTITY) //主键自动生成策略
    private Integer id;
    //@Column定义列名和属性，默认为字段名
    @Column
    private String name;
    @Column
    private int age;

    public Integer getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

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

UserRepository

package com.mohai.one.springbootjpa.repository;

import com.mohai.one.springbootjpa.domain.UserEntity;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.Modifying;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface UserRepository extends JpaRepository<UserEntity,Integer> {

    List<UserEntity> findAllByName(String name);

    @Modifying
    @Query(value = "insert into user(id,name,age) values(:id,:name,:age)",nativeQuery = true)
    int insertNameAndAge(@Param("id") Integer id, @Param("name") String name, @Param("age") int age);

}

UserService

package com.mohai.one.springbootjpa.service;

import com.mohai.one.springbootjpa.domain.UserEntity;
import com.mohai.one.springbootjpa.repository.UserRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.ArrayList;
import java.util.List;

@Service
public class UserService {

    @Autowired
    private UserRepository userRepository;

    //查
    public List<UserEntity> getAll(){
        return userRepository.findAll();
    }

    //查
    public List<UserEntity> findAllByName(String name){
        return userRepository.findAllByName(name);
    }

    //通过id查询
    public UserEntity getOne(Integer id){
        return userRepository.findById(id).get();
    }

    //改
    @Transactional
    public UserEntity updateUser(UserEntity userEntity){
        return userRepository.saveAndFlush(userEntity);
    }

    //增
    @Transactional
    public int insertUser(UserEntity userEntity){
        return userRepository.insertNameAndAge(userEntity.getId(),userEntity.getName(),userEntity.getAge());
    }

    //删
    @Transactional
    public void deleteUserById(Integer id){
        userRepository.deleteById(id);
    }

}

UserController

package com.mohai.one.springbootjpa.controller;

import com.mohai.one.springbootjpa.domain.UserEntity;
import com.mohai.one.springbootjpa.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

/**
 * @Created by moerhai@qq.com
 */
@RestController
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserService userService;

    @RequestMapping("/findAll")
    public List<UserEntity> findAll(){
        return userService.getAll();
    }

    @RequestMapping("/findAllByName")
    public List<UserEntity> findAllByName(String name){
        return userService.findAllByName(name);
    }

    //通过主键Id查询
    @RequestMapping("/getOne/{id}")
    public UserEntity getUserById(@PathVariable Integer id){
        return userService.getOne(id);
    }

    @RequestMapping("/save")
    public int save(@RequestBody UserEntity userEntity){
        return userService.insertUser(userEntity);
    }

    @RequestMapping("/edit")
    public UserEntity edit(@RequestBody UserEntity userEntity){
        return userService.updateUser(userEntity);
    }

    @RequestMapping("/delete")
    public int delete(@RequestParam("id") Integer id){
         userService.deleteUserById(id);
         return 1;
    }
}