jpa是JavaEE定义的一种规范，常用的实现一般是Hibernate，而spring-data-jpa则是对jpa的又一层封装，提供了更多便捷的方法。

这里不会深入讲解spring-data-jpa的使用，只是讲解怎么快速的整合使用，目的是帮助那些想学，但是在整合上老是翻车的同学

导入依赖

<dependency> <groupId>com.zaxxer</groupId> <artifactId>HikariCP</artifactId></dependency><dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId></dependency><dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId></dependency>

配置

spring: data: jpa: repositories: # 开启jpa enabled: true bootstrap-mode: default jpa: # 数据库方言 database-platform: org.hibernate.dialect.MySQL57Dialect open-in-view: false # 打印SQL show-sql: false properties: # 格式化输出的SQL语句 hibernate.format_sql: false hibernate: # 自动建表策略 ddl-auto: update

这里忽略了数据源的配置

关于自动建表策略

# 枚举值spring.jpa.hibernate.ddl-autocreate 不管表是否存在, 每次启动都会重新建表(会导致数据丢失)create-drop 启动的时候创建表, 程序退出(SessionFactory关闭)的时候删除表none 不进行任何操作update 如果数据表不存在则创建, 在实体对象被修改后,下次启动重新修改表结构(不会删除已经存在的数据)validate 启动的时候验证数据表的结构,

相关的配置类

这里仅仅列出了部分常用的配置，如果需要了解所有的配置信息，可以参考配置类

JpaPropertiesSpringDataWebPropertiesHibernateProperties

相关配置的文档docs.spring.io/spring-boot…

定义实体类User

import java.io.Serializable;import java.time.LocalDateTime;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.Enumerated;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import javax.persistence.Index;import javax.persistence.Table;// 指定表名称@Table(name = "user", indexes = { // 定义索引 @Index(columnList = "account", unique = true) })// 标识实体类@Entity// 设置表注释@org.hibernate.annotations.Table(appliesTo = "user", comment = "用户")public class User implements Serializable { /** * */ private static final long serialVersionUID = 4953012795378725917L; @Id // id 字段 @Column(columnDefinition = "INT(11) UNSIGNED COMMENT 'id'") @GeneratedValue(strategy = GenerationType.IDENTITY) // 自增 private Integer id; // 账户 @Column(columnDefinition = "VARCHAR(50) COMMENT '登录账户'", nullable = false) private String account; // 密码 @Column(columnDefinition = "VARCHAR(255) COMMENT '登录密码'", nullable = false) private String password; // 性别 @Column(columnDefinition = "TINYINT(1) COMMENT '性别。0：男，1：女'", nullable = false) @Enumerated private Gender gender; // 创建时间 @Column(name = "created_date", columnDefinition = "timestamp DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间'", nullable = false) private LocalDateTime createdDate; // 最后修改时间 @Column(name = "last_modified_date", columnDefinition = "timestamp NULL DEFAULT NULL COMMENT '最后一次修改时间'") private LocalDateTime lastModifiedDate; // 记录状态 @Column(columnDefinition = "TINYINT(1) unsigned COMMENT '是否启用'", nullable = false) private Boolean enabled; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getAccount() { return account; } public void setAccount(String account) { this.account = account; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public Gender getGender() { return gender; } public void setGender(Gender gender) { this.gender = gender; } public LocalDateTime getCreatedDate() { return createdDate; } public void setCreatedDate(LocalDateTime createdDate) { this.createdDate = createdDate; } public LocalDateTime getLastModifiedDate() { return lastModifiedDate; } public void setLastModifiedDate(LocalDateTime lastModifiedDate) { this.lastModifiedDate = lastModifiedDate; } public Boolean getEnabled() { return enabled; } public void setEnabled(Boolean enabled) { this.enabled = enabled; } @Override public String toString() { return "User [id=" + id + ", account=" + account + ", password=" + password + ", gender=" + gender + ", createdDate=" + createdDate + ", lastModifiedDate=" + lastModifiedDate + ", enabled=" + enabled + "]"; } public static enum Gender { BOY, GIRL }}

Repository

抽象出BaseRepository

import org.springframework.data.jpa.repository.JpaRepository;import org.springframework.data.jpa.repository.JpaSpecificationExecutor;import org.springframework.data.repository.NoRepositoryBean;@NoRepositoryBean // 该接口不是一个Repository，不需要生成代理实现public interface BaseRepository <T, ID> extends JpaRepository<T, ID>, JpaSpecificationExecutor <T> // , QuerydslPredicateExecutor<T> 如果使用了QueryDSL还可以实现这个接口{}

定义 UserRepository

import io.springboot.jpa.entity.User;public interface UserRepository extends BaseRepository<User, Integer> {}

Service

抽象出 BaseService

import org.springframework.data.jpa.repository.JpaRepository;import org.springframework.data.jpa.repository.JpaSpecificationExecutor;public interface BaseService<T, ID> extends JpaRepository<T, ID>, JpaSpecificationExecutor <T> // , QuerydslPredicateExecutor<T> {}

抽象出 AbstractService

import java.util.List;import java.util.Optional;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.data.domain.Example;import org.springframework.data.domain.Page;import org.springframework.data.domain.Pageable;import org.springframework.data.domain.Sort;import org.springframework.data.jpa.domain.Specification;import org.springframework.transaction.annotation.Transactional;import io.springboot.jpa.repository.BaseRepository;public abstract class AbstractService<T, ID> implements BaseService <T, ID> { /** * 泛型注入 */ @Autowired protected BaseRepository<T, ID> baseRepository; @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public List<T> findAll() { return this.baseRepository.findAll(); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public List<T> findAll(Sort sort) { return this.baseRepository.findAll(sort); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public List<T> findAllById(Iterable<ID> ids) { return this.baseRepository.findAllById(ids); } @Override @Transactional(rollbackFor = Throwable.class) public <S extends T> List<S> saveAll(Iterable<S> entities) { return this.baseRepository.saveAll(entities); } @Override @Transactional(rollbackFor = Throwable.class) public void flush() { this.baseRepository.flush(); } @Transactional(rollbackFor = Throwable.class) public <S extends T> S saveAndFlush(S entity) { return this.baseRepository.saveAndFlush(entity); } @Override @Transactional(rollbackFor = Throwable.class) public void deleteInBatch(Iterable<T> entities) { this.baseRepository.deleteInBatch(entities); } @Override @Transactional(rollbackFor = Throwable.class) public void deleteAllInBatch() { this.baseRepository.deleteAllInBatch(); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public T getOne(ID id) { return this.baseRepository.getOne(id); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public <S extends T> List<S> findAll(Example<S> example) { return this.baseRepository.findAll(example); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public <S extends T> List<S> findAll(Example<S> example, Sort sort) { return this.baseRepository.findAll(example, sort); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public Page<T> findAll(Pageable pageable) { return this.baseRepository.findAll(pageable); } @Override @Transactional(rollbackFor = Throwable.class) public <S extends T> S save(S entity) { return this.baseRepository.save(entity); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public Optional<T> findById(ID id) { return this.baseRepository.findById(id); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public boolean existsById(ID id) { return this.baseRepository.existsById(id); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public long count() { return this.baseRepository.count(); } @Override @Transactional(rollbackFor = Throwable.class) public void deleteById(ID id) { this.baseRepository.deleteById(id); } @Override @Transactional(rollbackFor = Throwable.class) public void delete(T entity) { this.baseRepository.delete(entity); } @Override @Transactional(rollbackFor = Throwable.class) public void deleteAll(Iterable<? extends T> entities) { this.baseRepository.deleteAll(entities); } @Override @Transactional(rollbackFor = Throwable.class) public void deleteAll() { this.baseRepository.deleteAll(); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public <S extends T> Optional<S> findOne(Example<S> example) { return this.baseRepository.findOne(example); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public <S extends T> Page<S> findAll(Example<S> example, Pageable pageable) { return this.baseRepository.findAll(example, pageable); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public <S extends T> long count(Example<S> example) { return this.baseRepository.count(example); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public <S extends T> boolean exists(Example<S> example) { return this.baseRepository.exists(example); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public Optional<T> findOne(Specification<T> spec) { return this.baseRepository.findOne(spec); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public List<T> findAll(Specification<T> spec) { return this.baseRepository.findAll(spec); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public Page<T> findAll(Specification<T> spec, Pageable pageable) { return this.baseRepository.findAll(spec, pageable); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public List<T> findAll(Specification<T> spec, Sort sort) { return this.baseRepository.findAll(spec, sort); } @Override @Transactional(readOnly = true, rollbackFor = Throwable.class) public long count(Specification<T> spec) { return this.baseRepository.count(spec); }}

定义 UserService

import org.springframework.stereotype.Service;import io.springboot.jpa.entity.User;@Servicepublic class UserService extends AbstractService<User, Integer> { }

添加注解驱动

import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.boot.autoconfigure.domain.EntityScan;import org.springframework.data.jpa.repository.config.EnableJpaRepositories;@SpringBootApplication@EnableJpaRepositories(basePackages = { "io.springboot.jpa.repository" })@EntityScan(basePackages = { "io.springboot.jpa.entity" })public class JpaApplication { public static void main(String[] args) { SpringApplication.run(JpaApplication.class, args); }}

@EnableJpaRepositories指定repository所在的包@EntityScan指定entity所在的包

测试

import io.springboot.jpa.JpaApplication;import io.springboot.jpa.entity.User;import io.springboot.jpa.service.UserService;import java.time.LocalDateTime;import org.junit.Test;import org.junit.runner.RunWith;import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.boot.test.context.SpringBootTest;import org.springframework.test.context.junit4.SpringRunner;@RunWith(SpringRunner.class)@SpringBootTest(classes = JpaApplication.class, webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)public class JpaApplicationTest { static final Logger LOGGER = LoggerFactory.getLogger(JpaApplicationTest.class); @Autowired UserService userService; @Test public void test () { // 存储 User user = new User(); user.setAccount("kevinblandy.cn@gmail.com"); user.setPassword("123456"); user.setGender(User.Gender.GIRL); user.setEnabled(Boolean.TRUE); user.setCreatedDate(LocalDateTime.now()); this.userService.save(user); LOGGER.info("save success....."); // 检索 User results = this.userService.findById(user.getId()).orElseGet(null); LOGGER.info("query result={}", results); }}

自动创建的表

CREATE TABLE `user` ( `id` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT 'id', `account` varchar(50) NOT NULL COMMENT '登录账户', `created_date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间', `enabled` tinyint(1) unsigned NOT NULL COMMENT '是否启用', `gender` tinyint(1) NOT NULL COMMENT '性别。0：男，1：女', `last_modified_date` timestamp NULL DEFAULT NULL COMMENT '最后一次修改时间', `password` varchar(255) NOT NULL COMMENT '登录密码', PRIMARY KEY (`id`), UNIQUE KEY `UKdnq7r8jcmlft7l8l4j79l1h74` (`account`)) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='用户';

执行的日志

Hibernate: insert into user (account, created_date, enabled, gender, last_modified_date, password) values (?, ?, ?, ?, ?, ?)2020-06-23 17:57:36.264 INFO 7612 --- [ main] i.s.jpa.test.JpaApplicationTest : save success.....Hibernate: select user0_.id as id1_0_0_, user0_.account as account2_0_0_, user0_.created_date as created_3_0_0_, user0_.enabled as enabled4_0_0_, user0_.gender as gender5_0_0_, user0_.last_modified_date as last_mod6_0_0_, user0_.password as password7_0_0_ from user user0_ where user0_.id=?2020-06-23 17:57:36.303 INFO 7612 --- [ main] i.s.jpa.test.JpaApplicationTest : query result=User [id=1, account=kevinblandy.cn@gmail.com, password=123456, gender=GIRL, createdDate=2020-06-23T17:57:36, lastModifiedDate=null, enabled=true]

总结

到此这篇关于SpringBoot整合spring-data-jpa的方法的文章就介绍到这了,更多相关SpringBoot整合spring-data-jpa内容请搜索以前的文章或继续浏览下面的相关文章希望大家以后多多支持！