springboot2.0整合jpa

Posted 2021-01-08

在整合的遇到各种坑，以下是我整合的流程

1、pom.xml文件

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jooq</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-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

2、application.properties文件，这里特意说明以下，我这里用的是spring data jpa 2.10版本，支持的数据库驱动有三种，分别是hikari、tomcat-jdbc，dbcp2，优先是hikari，其他两个需要单独导入包：

#hikari
spring.datasource.hikari.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.hikari.jdbc-url=jdbc:mysql://127.0.0.1:3306/yangld?useUnicode=true&characterEncoding=utf-8
spring.datasource.hikari.username=root
spring.datasource.hikari.password=1234

spring.jpa.database-platform=org.hibernate.dialect.MySQL57Dialect
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=create

3、JpaConfig类配置有两种形式，一种是xml方式，还有注解的方式，我们用的是springboot，xml的形式是我们要唾弃的，所以用注解的形式：

@Configuration
@EnableJpaRepositories(basePackages={"com.example.springbootdemo.dao"}) //这个是你Repositorie所在的包
@EnableTransactionManagement //这个是事务
public class JpaConfig{


    @Primary //springboot默认是多数据源，所以你要指定一个主数据源，不然会错误
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource.hikari") //需要导入配置
    public DataSource dataSource(){
        return DataSourceBuilder.create().build();
    }

    @Primary //springboot默认是多数据源，所以你要指定一个主数据源，不然会错误
    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        vendorAdapter.setGenerateDdl(true);
        vendorAdapter.setDatabase(Database.MYSQL);//这里指定的你数据库的类型
        LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
        factory.setJpaVendorAdapter(vendorAdapter);
        factory.setPackagesToScan("com.example.springbootdemo.entity");//这个是你entity所在的包
        factory.setDataSource(dataSource());
        return factory;
    }

    @Bean
    public PlatformTransactionManager transactionManager(EntityManagerFactory entityManagerFactory) {
        JpaTransactionManager txManager = new JpaTransactionManager();
        txManager.setEntityManagerFactory(entityManagerFactory);
        return txManager;
    }

}

4、dao层的Repository

@Repository
public interface CityRepository extends JpaRepository<City,Integer> {

}

5、实体类

@Entity
@Getter
@Setter
public class City {
    @Id
    @GeneratedValue
    @Column(name="id")
    private Integer id;
    @Column(name="name")
    private String name;
    @Column(name="countryCode")
    private String countryCode;
    @Column(name="district")
    private String district;
    @Column(name="population")
    private String population;
}

6、controller层

@RestController
public class WorkController {

    @Autowired
    private CityRepository cityRepository;

    @RequestMapping("/list")
    public List<City> queryCityAll(){
        return cityRepository.findAll();
    }
}

7、整合完毕
http://localhost:8080/list