......
<dependency>
<groupId>com.github.alittlehuang</groupId>
<artifactId>jpa-spec-query</artifactId>
<version>1.1.0</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>${hibernate.version}</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-c3p0</artifactId>
<version>${hibernate.version}</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${mysql.version}</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>${logback.version}</version>
</dependency>
......SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;
-- ----------------------------
-- Table structure for company
-- ----------------------------
DROP TABLE IF EXISTS `company`;
CREATE TABLE `company` (
`id` int(11) NOT NULL,
`addr` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
`name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;
-- ----------------------------
-- Records of company
-- ----------------------------
INSERT INTO `company` VALUES (1, 'ShangHai', 'Microsoft');
-- ----------------------------
-- Table structure for user
-- ----------------------------
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
`id` int(11) NOT NULL,
`age` int(11) NULL DEFAULT NULL,
`company_id` int(11) NULL DEFAULT NULL,
`name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
PRIMARY KEY (`id`) USING BTREE,
INDEX `FK2yuxsfrkkrnkn5emoobcnnc3r`(`company_id`) USING BTREE,
CONSTRAINT `FK2yuxsfrkkrnkn5emoobcnnc3r` FOREIGN KEY (`company_id`) REFERENCES `company` (`id`) ON DELETE RESTRICT ON UPDATE RESTRICT
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;
-- ----------------------------
-- Records of user
-- ----------------------------
INSERT INTO `user` VALUES (1, 18, 1, 'Luna');
SET FOREIGN_KEY_CHECKS = 1;
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
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/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa.xsd">
<context:component-scan base-package="com.github"/>
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
<property name="driverClass" value="com.mysql.jdbc.Driver"/>
<property name="jdbcUrl" value="jdbc:mysql:///test"/>
<property name="user" value="root"/>
<property name="password" value="root"/>
</bean>
<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"/>
</property>
<property name="packagesToScan" value="com.github"/>
<property name="jpaProperties">
<props>
<prop key="hibernate.dialect.storage_engine">innodb</prop>
<prop key="hibernate.ejb.naming_strategy">org.hibernate.cfg.ImprovedNamingStrategy</prop>
<prop key="hibernate.show_sql">false</prop>
<prop key="hibernate.format_sql">true</prop>
<prop key="hibernate.hbm2ddl.auto">update</prop>
<prop key="hibernate.enable_lazy_load_no_trans">update</prop>
</props>
</property>
</bean>
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory"/>
</bean>
<jpa:repositories base-package="com.github" repository-impl-postfix="Impl"
entity-manager-factory-ref="entityManagerFactory" transaction-manager-ref="transactionManager"/>
<tx:annotation-driven/>
</beans>@Data
@Entity
@Table(name = "company")
public class Company {
@Id
private Integer id;
private String name;
private String addr;
}@Data
@Entity
@Table(name = "user")
public class User {
@Id
private Integer id;
private String name;
private Integer age;
@Column(name = "company_id")
private Integer companyId;
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "company_id", updatable = false, insertable = false)
private Company company;
}public class Demo {
public static void main(String[] args) {
ApplicationContext appCtx = new ClassPathXmlApplicationContext("config/applicationContext.xml");
EntityManager entityManager = appCtx.getBean(EntityManager.class);
TypeRepository<User> repository = new TypeRepository<>(User.class, entityManager);
//select by id
User selectById = repository.query()
.andEqual(User::getId, 1)
.getSingleResult();
// fetch:
// select user inner join company
User fetch = repository.query()
.andEqual(User::getId, 1)
.addFetchs(User::getCompany)
.getSingleResult();
// select by name and age
User luna = repository.query()
.andEqual(User::getName, "Luna")
.andEqual(User::getAge, 18)
.getSingleResult();
// select user by company name
List<User> list = repository.query()
.andEqual(Path.of(User::getCompany).to(Company::getName), "Microsoft")
.getResultList();
}
}