java config 配置 spring data jpa

本文介绍如何通过java config方式配置JPA，其中数据源使用 hikari，在 spring boot 2.0 下正常运行

maven:

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>42.2.5</version>
        </dependency>
        <dependency>
            <groupId>com.zaxxer</groupId>
            <artifactId>HikariCP</artifactId>
            <version>2.7.8</version>
        </dependency>

application.yml

database:
  jdbcUrl: jdbc:postgresql://localhost:5432/yourdb?prepareThreshold=0
  username: root
  password: "123456"
  poolName: csis-common
  maxPoolSize: 5
  minIdle: 1
  connectionTestQuery: select 1
  driverClassName: org.postgresql.Driver

java 配置

@EnableJpaRepositories(
        basePackages = "com.royalnu.csis.ms.example.provider",  // 更改对应repository & pojo 包名 
        entityManagerFactoryRef = "exampleEntityManager",   // 与java bean 定义一致
        transactionManagerRef = "exampleTransactionManager"  // 与java bean 定义一致
)

java bean定义

    //....
    // 定义数据源
    @Bean
    @ConfigurationProperties(prefix = "datasource")
    public DataSource dataSource() {
        return new HikariDataSource();
    }

    @Bean
    public LocalContainerEntityManagerFactoryBean exampleEntityManager()  {
        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        vendorAdapter.setDatabasePlatform("org.hibernate.dialect.PostgreSQLDialect");
        vendorAdapter.setShowSql(true);
        vendorAdapter.setDatabase(Database.valueOf("POSTGRESQL"));
        vendorAdapter.setGenerateDdl(false);

        LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
        factory.setJpaVendorAdapter(vendorAdapter);
        // 更改为对应包名，包括 repository 及 pojo ，建议放到同级不同子目录
        factory.setPackagesToScan("com.royalnu.csis.ms.example.provider");
        factory.setDataSource(dataSource());
        factory.setJpaProperties(jpaProperties());
        return factory;
    }

    @Bean
    private Properties jpaProperties() {
        Properties properties = new Properties();
        properties.put("hibernate.temp.use_jdbc_metadata_defaults", "false");
        return properties;
    }

    @Bean
    public PlatformTransactionManager exampleTransactionManager() {
        JpaTransactionManager txManager = new JpaTransactionManager();
    
 txManager.setEntityManagerFactory(exampleEntityManager().getObject());
        return txManager;
    }

repository：

package com.royalnu.csis.ms.example.provider.repository;

import com.royalnu.csis.ms.example.provider.pojo.Teacher;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface TeacherRepository extends JpaRepository<Teacher, Integer> {
}

pojo:

package com.royalnu.csis.ms.example.provider.pojo;
import lombok.Data;
import javax.persistence.*;

@Data
@Table(name = "t_teacher")
@Entity
public class Teacher {
    @Id
    @GeneratedValue(strategy= GenerationType.AUTO)
    protected Integer id;
    protected String name;
    @Column(name = "job_title")
    protected String jobTitle;

    public Teacher() {}

    public Teacher(String name, String jobTitle) {
        this.name = name;
        this.jobTitle = jobTitle;
    }

}