springboot整合spring data jpa实例

骑猪看日落 2022-05-13 12:52 218阅读 0赞

这里不多介绍jpa和springboot只做使用的实际配置  
打好springboot项目之后配置数据源

首先加入pom依赖

jpa，mysql，lombok(实体上加上@Data注解可以省去get，set，toString，等方法)

<dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-data-jpa</artifactId>
       </dependency>
       <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>${mysql.version}</version>
                <scope>runtime</scope>
        </dependency>
    
        <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
        </dependency>

第一步：数据源链接配置和jpa相关配置

配置application.yml文件的数据源和jpa

spring:
      datasource:
        url: jdbc:mysql://172.20.94.39:3306/marketing?characterEncoding=utf-8&verifyServerCertificate=false&useSSL=false&requireSSL=false
        driver-class-name: com.mysql.cj.jdbc.Driver
        username: marketing
        password: marketing
      jpa:
        hibernate:
          ddl-auto: update
        show-sql: true
        database: mysql

第二步：配置数据源配置文件

package com.renrenche.marketing.ads_scheduler.config;
    
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.context.annotation.Primary;
    import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
    import org.springframework.jdbc.datasource.DriverManagerDataSource;
    import org.springframework.orm.jpa.JpaTransactionManager;
    import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
    import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
    import org.springframework.transaction.PlatformTransactionManager;
    import org.springframework.transaction.annotation.EnableTransactionManagement;
    
    import javax.persistence.EntityManagerFactory;
    import javax.sql.DataSource;
    import java.util.HashMap;
    import java.util.Map;
    
    @Configuration
    //此处是你dao文件所在的包名
    @EnableJpaRepositories("com.renrenche.marketing.ads_scheduler.dao")
    @EnableTransactionManagement
    public class DataSourceConfig {
    
        @Autowired
        private DataSource dataSource;
        @Value("${spring.jpa.hibernate.ddl-auto}")
        private String ddlAuto;
        @Value("${spring.jpa.show-sql}")
        private String showSql;
        @Primary
        @Bean
        public EntityManagerFactory entityManagerFactory() {
            HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
    
            LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();
            factory.setJpaVendorAdapter(vendorAdapter);
            //此处com.example.*.model是你的java bean所在的包名
            factory.setPackagesToScan("com.renrenche.marketing.ads_scheduler.domain");
            factory.setDataSource(dataSource);
    
            Map<String, Object> jpaProperties = new HashMap<String, Object>();
            jpaProperties.put("hibernate.ejb.naming_strategy","org.hibernate.cfg.ImprovedNamingStrategy");
            jpaProperties.put("hibernate.jdbc.batch_size",50);
            //以下是配置自动创建表结构
            jpaProperties.put("hibernate.hbm2ddl.auto", ddlAuto);
            jpaProperties.put("hibernate.format_sql", "true");
            jpaProperties.put("hibernate.show_sql", showSql);
            jpaProperties.put("hibernate.dialect", "org.hibernate.dialect.MySQL5InnoDBDialect");
           
    
            factory.setJpaPropertyMap(jpaProperties);
            factory.afterPropertiesSet();
            return factory.getObject();
        }
        @Primary
        @Bean
        public PlatformTransactionManager transactionManager() {
    
            JpaTransactionManager txManager = new JpaTransactionManager();
            txManager.setEntityManagerFactory(entityManagerFactory());
            return txManager;
        }
    }

接下来就可以创建实体。利用实体配置直接在数据库生成表结构

package com.renrenche.marketing.ads_scheduler.domain.sem;
    
    import lombok.Data;
    import org.hibernate.annotations.CreationTimestamp;
    import org.hibernate.annotations.UpdateTimestamp;
    import javax.persistence.*;
    import java.io.Serializable;
    import java.util.Date;
    
    @Entity
    @Table(name = "sem_channel")
    @Data
    public class SemChannelEntity implements Serializable {
    
        private static final long serialVersionUID = -5654459077990963779L;
    
        @Id
        @GeneratedValue(strategy= GenerationType.IDENTITY)
        private Integer id;
    
        @Column(name = "channel_en")
        private String channelEn;
    
        @Column(name = "channel_cn")
        private String channelCn;
    
        @Column(name = "discription")
        private String discription;
    
        @Column(name = "status")
        private Integer status;
    
        @Column(name = "create_time")
        @CreationTimestamp
        private Date createTime;
    
        @UpdateTimestamp
        @Column(name = "update_time")
        private Date updateTime;
    }

运行springboot项目即可在数据库生成表

console控制台打印日志

![70][]

创建成功，可以在库里看到建好的表

[70]: /images/20220504/73319c3ee68c4bc59e319c60559e15f4.png