002_Spring Data JPA CRUD

最新推荐文章于 2022-07-14 19:17:58 发布

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本文介绍了如何在Java项目中使用Spring Data JPA进行CRUD操作，包括创建User实体、Repository接口、Service接口和实现，以及JUnit单元测试的集成。涵盖了添加、批量添加、查询、更新和删除用户实例的功能演示。

1. 创建一个名为spring-data-jpa-crud的Java项目, 同时添加相关jar包, 并添加JUnit能力。

2. 查看CrudRepository接口下的方法, 我们使用红色框中的方法。

3. 新建User.java

package com.bjbs.pojo;

import java.io.Serializable;
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import org.springframework.format.annotation.DateTimeFormat;

@Entity // 指定该类是实体类
@Table(name = "user") // 指定数据库表名(表名和实体类对应)
public class User implements Serializable {
	private static final long serialVersionUID = 1L;

	@Id // 指定为主键
	@GeneratedValue(strategy = GenerationType.IDENTITY) // 指定主键生成策略
	@Column(name = "id") // 指定表中列名(列名和属性名对应)
	private Integer id;

	@Column(name = "name")
	private String name;

	@Column(name = "sex")
	private String sex;
	
	@Column(name = "birthday")
	@DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")
	private Date birthday;

	@Column(name = "address")
	private String address;

	public User() {
	}

	public User(String name, String sex, Date birthday, String address) {
		this.name = name;
		this.sex = sex;
		this.birthday = birthday;
		this.address = address;
	}

	public User(Integer id, String name, String sex, Date birthday, String address) {
		this.id = id;
		this.name = name;
		this.sex = sex;
		this.birthday = birthday;
		this.address = address;
	}

	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 String getSex() {
		return sex;
	}

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

	public Date getBirthday() {
		return birthday;
	}

	public void setBirthday(Date birthday) {
		this.birthday = birthday;
	}

	public String getAddress() {
		return address;
	}

	public void setAddress(String address) {
		this.address = address;
	}

	@Override
	public String toString() {
		return "User [id=" + id + ", name=" + name + ", sex=" + sex + ", birthday=" + birthday + ", address=" + address
				+ "]";
	}
}

4. 新建UserRepository.java

package com.bjbs.dao;

import org.springframework.data.repository.CrudRepository;
import com.bjbs.pojo.User;

/**
 * 参数一T: 当前需要映射的实体; 参数二 T: 当前映射的实体中的id的类型
 */
public interface UserRepository extends CrudRepository<User, Integer> {

}

5. 新建UserService.java

package com.bjbs.service;

import com.bjbs.pojo.User;

public interface UserService {
	User save(User user);

	Iterable<User> save(Iterable<User> users);
	
	User findOne(Integer id);
	
	Iterable<User> findAll();

	void delete(Integer id);

	void delete(User user);

	void delete(Iterable<User> users);
}

6. 新建UserServiceImpl.java

package com.bjbs.service.impl;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import com.bjbs.dao.UserRepository;
import com.bjbs.pojo.User;
import com.bjbs.service.UserService;

@Service
@Transactional
public class UserServiceImpl implements UserService {
	@Autowired
	private UserRepository userRepository;

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

	@Override
	public Iterable<User> save(Iterable<User> users) {
		return userRepository.save(users);
	}

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

	@Override
	public Iterable<User> findAll() {
		return userRepository.findAll();
	}

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

	@Override
	public void delete(User user) {
		userRepository.delete(user);
	}

	@Override
	public void delete(Iterable<User> users) {
		userRepository.delete(users);
	}
	
}

7. 新建TestUserRepository.java

package com.bjbs.test;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import com.bjbs.pojo.User;
import com.bjbs.service.UserService;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class TestUserRepository {
	@Autowired
	private UserService userService;
	
	/**
	 * 添加
	 */
	@Test
	public void addOne() {
		User user = new User("曹整", "男", new Date(), "河南省开封市");
		User userDb = userService.save(user);
		System.out.println(userDb);
	}
	
	/**
	 * 批量添加
	 */
	@Test
	public void addMore(){
		User caoShuo = new User("曹铄", "男", new Date(), "河南省开封市");
		User qingHe = new User("清河公主", "女", new Date(), "河南省开封市");
		List<User> users = new ArrayList<User>();
		users.add(caoShuo);
		users.add(qingHe);
		Iterable<User> usersDb = userService.save(users);
		for (User user : usersDb) {
			System.out.println(user);
		}
	}
	
	/**
	 * 根据id查询
	 */
	@Test
	public void findOne() {
		User userDb = userService.findOne(40);
		System.out.println(userDb);
	}
	
	/**
	 * 更新
	 */
	@Test
	public void update(){
		User userDb = userService.findOne(56);
		System.out.println(userDb);
		userDb.setAddress("河南省郑州市");
		userDb = userService.save(userDb);
		System.out.println(userDb);
	}
	
	/**
	 * 查询所有
	 */
	@Test
	public void findAll(){
		Iterable<User> usersDb = userService.findAll();
		for (User user : usersDb) {
			System.out.println(user);
		}
	}
	
	/**
	 * 根据id删除
	 */
	@Test
	public void deleteById(){
		userService.delete(50);
	}
	
	/**
	 * 根据用户删除, 必须设置主键id
	 */
	@Test
	public void deleteByUser(){
		User user = new User();
		user.setId(56);
		userService.delete(user);
	}
	
	/**
	 * 根据用户删除
	 */
	@Test
	public void deleteByUsers(){
		User user1 = new User();
		user1.setId(45);
		User user2 = new User();
		user2.setId(46);
		List<User> users = new ArrayList<User>();
		users.add(user1);
		users.add(user2);
		userService.delete(users);
	}
}

8. 在src下新建application.properties

spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://192.168.25.138:3306/StudyMybatis?useSSL=true&useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai
spring.datasource.username=root
spring.datasource.password=lyw123456

9. 在src下新建applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://www.springframework.org/schema/beans"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xmlns:jpa="http://www.springframework.org/schema/data/jpa"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
	http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
	http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa.xsd
	http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
	
	<!-- 配置读取properties文件的工具类 -->
	<context:property-placeholder location="classpath:application.properties" />

	<!-- 配置c3p0数据库连接池 -->
	<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
		<property name="jdbcUrl" value="${spring.datasource.url}" />
		<property name="driverClass" value="${spring.datasource.driverClassName}" />
		<property name="user" value="${spring.datasource.username}" />
		<property name="password" value="${spring.datasource.password}" />
	</bean>

	<!-- Spring整合JPA 配置EntityManagerFactory -->
	<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
		<property name="dataSource" ref="dataSource" />
		<property name="jpaVendorAdapter">
			<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
				<!-- hibernate相关的属性的注入 -->
				<!-- 配置数据库类型 -->
				<property name="database" value="MYSQL" />
				<!-- 正向工程 自动创建表 -->
				<!-- <property name="generateDdl" value="true" /> -->
				<!-- 显示执行的SQL -->
				<property name="showSql" value="true" />
			</bean>
		</property>
		<!-- 扫描实体的包 -->
		<property name="packagesToScan">
			<list>
				<value>com.bjbs.pojo</value>
			</list>
		</property>
	</bean>

	<!-- 配置Hibernate的事务管理器 -->
	<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
		<property name="entityManagerFactory" ref="entityManagerFactory" />
	</bean>

	<!-- 配置开启注解事务处理 -->
	<tx:annotation-driven transaction-manager="transactionManager" />

	<!-- 配置springIOC的注解扫描 -->
	<context:component-scan base-package="com.bjbs.service" />

	<!-- Spring Data JPA 的配置 -->
	<!-- base-package: 扫描dao接口所在的包 -->
	<jpa:repositories base-package="com.bjbs.dao" />
</beans>

10. 数据库user表