JPA---Spring-data-JPA---Hibernate
Posted 雨听风说
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Spring Data JPA--搭建环境
版本---maven 3.6.3
<properties>
<spring.version>5.2.5.RELEASE</spring.version> Spring的版本
<hibernate.version>5.4.10.Final</hibernate.version> hibernate的版本
<slf4j.version>1.7.30</slf4j.version>
<log4j.version>2.12.1</log4j.version>
<druid.version>1.1.21</druid.version>
<mysql.version>5.1.6</mysql.version>
</properties>
导入依赖坐标
<dependencies> <!-- spring beg --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.9.5</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>${spring.version}</version> </dependency> <!-- spring对orm框架的支持包--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring.version}</version> </dependency> <!-- hibernate beg --> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-entitymanager</artifactId> <version>${hibernate.version}</version> </dependency> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> <version>${hibernate.version}</version> </dependency> <dependency> <groupId>org.hibernate.validator</groupId> <artifactId>hibernate-validator</artifactId> <version>6.1.2.Final</version> <exclusions> <exclusion> <artifactId>classmate</artifactId> <groupId>com.fasterxml</groupId> </exclusion> </exclusions> </dependency> <!-- hibernate end --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql.version}</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>${druid.version}</version> </dependency> <!-- spring data jpa 的坐标 --> <dependency> <groupId>org.springframework.data</groupId> <artifactId>spring-data-jpa</artifactId> <version>2.2.6.RELEASE</version> <exclusions> <exclusion> <artifactId>slf4j-api</artifactId> <groupId>org.slf4j</groupId> </exclusion> </exclusions> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>${spring.version}</version> </dependency> <!-- el beg 使用spring data jpa 必须引入 --> <dependency> <groupId>javax.el</groupId> <artifactId>javax.el-api</artifactId> <version>3.0.0</version> </dependency> <dependency> <groupId>org.glassfish</groupId> <artifactId>javax.el</artifactId> <version>3.0.0</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>${slf4j.version}</version> </dependency> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-api</artifactId> <version>${log4j.version}</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency> </dependencies>
创建配置文件
applicatioContext.xml
<?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:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" xmlns:jdbc="http://www.springframework.org/schema/jdbc" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jpa="http://www.springframework.org/schema/data/jpa" xmlns:task="http://www.springframework.org/schema/task" xmlns:contxt="http://www.springframework.org/schema/context" xsi:schemaLocation=" http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc.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"> <!-- 配置实体类管理工厂 --> <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> <!-- 配置数据源 --> <property name="dataSource" ref="dataSource"/> <!-- 配置实体类包扫描 --> <property name="packagesToScan" value="com.ytfs.entity"/> <!-- 配置jpa提供方 --> <property name="persistenceProvider"> <bean class="org.hibernate.jpa.HibernatePersistenceProvider"/> </property> <!-- 配置JPA提供方的适配器 --> <property name="jpaVendorAdapter"> <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"> <!-- 是否显示sql语句 --> <property name="showSql" value="true"/> <!-- 数据库的类型 --> <property name="database" value="MYSQL"/> <!-- 数据库的方言 --> <property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect"/> <!-- 是否自动创建表 --> <property name="generateDdl" value="false"/> </bean> </property> </bean> <!-- 配置数据源 --> <contxt:property-placeholder location="classpath:jdbcConfig.properties"/> <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"> <property name="username" value="${jdbc.username}"/> <property name="driverClassName" value="${jdbc.driver}"/> <property name="url" value="${jdbc.url}"/> <property name="password" value="${jdbc.password}"/> </bean> <!-- 配置事务管理器 --> <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"> <property name="entityManagerFactory" ref="entityManagerFactory"/> </bean> <!-- 整合jpa --> <jpa:repositories base-package="com.ytfs.dao" transaction-manager-ref="transactionManager" entity-manager-factory-ref="entityManagerFactory"/> <!-- 配置上spring包扫描器 --> <context:component-scan base-package="com.ytfs"/>
jdbcConfig.xml
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/jpa
jdbc.username=root
jdbc.password=root
创建实体类
package com.ytfs.entity; import javax.persistence.*; import java.io.Serializable; /** * @Classname Customer * @Description TODO(客户实体类) * @Date 2020/4/29 21:34 * @Created by ytfs */ @Entity @Table(name = "cst_customer") public class Customer implements Serializable { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name = "cust_id") private Long custId; /** * cust_id` bigint(32) NOT NULL AUTO_INCREMENT COMMENT \'客户编号(主键)\', * `cust_name` varchar(32) NOT NULL COMMENT \'客户名称(公司名称)\', * `cust_source` varchar(32) DEFAULT NULL COMMENT \'客户信息来源\', * `cust_industry` varchar(32) DEFAULT NULL COMMENT \'客户所属行业\', * `cust_level` varchar(32) DEFAULT NULL COMMENT \'客户级别\', * `cust_address` varchar(128) DEFAULT NULL COMMENT \'客户联系地址\', * `cust_phone` v */ @Column(name = "cust_name") private String custName; @Column(name = "cust_source") private String custSource; @Column(name = "cust_industry") private String custIndustry; @Column(name = "cust_level") private String custLevel; @Column(name = "cust_address") private String custAddress; @Column(name = "cust_phone") private String custPhone; public Long getCustId() { return custId; } public void setCustId(Long custId) { this.custId = custId; } public String getCustName() { return custName; } public void setCustName(String custName) { this.custName = custName; } public String getCustSource() { return custSource; } public void setCustSource(String custSource) { this.custSource = custSource; } public String getCustIndustry() { return custIndustry; } public void setCustIndustry(String custIndustry) { this.custIndustry = custIndustry; } public String getCustLevel() { return custLevel; } public void setCustLevel(String custLevel) { this.custLevel = custLevel; } public String getCustAddress() { return custAddress; } public void setCustAddress(String custAddress) { this.custAddress = custAddress; } public String getCustPhone() { return custPhone; } public void setCustPhone(String custPhone) { this.custPhone = custPhone; } @Override public String toString() { return "Customer{" + "custId=" + custId + ", custName=\'" + custName + \'\\\'\' + ", custSource=\'" + custSource + \'\\\'\' + ", custIndustry=\'" + custIndustry + \'\\\'\' + ", custLevel=\'" + custLevel + \'\\\'\' + ", custAddress=\'" + custAddress + \'\\\'\' + ", custPhone=\'" + custPhone + \'\\\'\' + \'}\'; } }
创建dao接口
Spring Data JPA是spring提供的一款对于数据访问层（Dao层）的框架，使用Spring Data JPA，只需要按照框架的规范提供dao接口，不需要实现类就可以完成数据库的增删改查、分页查询等方法的定义，极大的简化了我们的开发过程。
在Spring Data JPA中，对于定义符合规范的Dao层接口，我们只需要遵循以下几点就可以了：
1.创建一个Dao层接口，并实现JpaRepository和JpaSpecificationExecutor
2.提供相应的泛型
package com.ytfs.dao; import com.alibaba.druid.sql.visitor.functions.If; import com.ytfs.entity.Customer; import org.hibernate.mapping.Value; import org.springframework.data.jpa.repository.JpaRepository; import org.springframework.data.jpa.repository.JpaSpecificationExecutor; import org.springframework.data.jpa.repository.Modifying; import org.springframework.data.jpa.repository.Query; import java.lang.invoke.VarHandle; import java.security.spec.NamedParameterSpec; import java.util.List; /** * @Classname CustomerDao * @Description TODO(客户的数据库访问层) * @Date 2020/4/29 21:46 * @Created by ytfs * JpaRepository<实体类类型，主键类型>：用来完成基本CRUD操作 * JpaSpecificationExecutor<实体类类型>：用于复杂查询（分页等查询操作） */ public interface CustomerDao extends JpaRepository<Customer, Long>, JpaSpecificationExecutor<Customer> { /** * JPQL的方式查询全部客户 * * @return */ @Query(value = "from Customer") List<Customer> findAllByJPQL(); /** * 根据客户名称和客户id查询客户 * jpql： from Customer where custName = ? and custId = ? * <p> * 对于多个占位符参数 * 赋值的时候，默认的情况下，占位符的位置需要和方法参数中的位置保持一致 * <p> * 可以指定占位符参数的位置 * ? 索引的方式，指定此占位的取值来源 */ @Query("from Customer where custName = ?2 and custId = ?1") Customer findCustomerById(Long custId, String custName); /** * 使用jpql完成更新操作 * 案例 ： 根据id更新，客户的名称 * 更新4号客户的名称，将名称改为“黑马程序员” * * sql ：update cst_customer set cust_name = ? where cust_id = ? * jpql : update Customer set custName = ? where custId = ? * * @Query : 代表的是进行查询 * * 声明此方法是用来进行更新操作 * @Modifying * * 当前执行的是一个更新操作 * */ @Query("update Customer set custName = ?1 where custId = ?2") @Modifying void updateCustomerById(String custName,Long Id); /** * 使用sql的形式查询： * 查询全部的客户 * sql ： select * from cst_customer; * Query : 配置sql查询 * value ： sql语句 * nativeQuery ： 查询方式 * true ： sql查询 * false：jpql查询 默认值 * */ @Query(value = "select * from cst_customer", nativeQuery = true) List<Customer> findAllBySql(); /** * 使用sql的形式查询： * 条件查询 * sql ： select * from cst_customer where cust_name like ?; * Query : 配置sql查询 * value ： sql语句 * nativeQuery ： 查询方式 * true ： sql查询 * false：jpql查询 默认值 * */ @Query(value = "select * from cst_customer where cust_name like ?1", nativeQuery = true) Customer FindCustomerByLikeCustName(String custName); /** * @author 雨听风说 * @param * @updateTime 2020/4/30 23:45 * 方法名的约定： * findBy : 查询 * 对象中的属性名（首字母大写） ： 查询的条件 * CustName * * 默认情况 ： 使用 等于的方式查询 * 特殊的查询方式 * * findByCustName -- 根据客户名称查询 * * 再springdataJpa的运行阶段 * 会根据方法名称进行解析 findBy from xxx(实体类) * 属性名称 where custName = * * 1.findBy + 属性名称 （根据属性名称进行完成匹配的查询=） * 2.findBy + 属性名称 + “查询方式（Like | isnull）” * findByCustNameLike * 3.多条件查询 * findBy + 属性名 + “查询方式” + “多条件的连接符（and|or）” + 属性名 + “查询方式” */ /** * 根据名称精准查询客户 * @param CustName * @return */ Customer findByCustName(String CustName); /** * 根据客户名称进行模糊查询 * @param CustName * @return */ List<Customer> findByCustNameLike(String CustName); /** * 根据客户名称模糊查询,并且通过id精确查询 * @param name * @param Id * @return */ List<Customer> findByCustNameLikeAndCustId(String name, Long Id); }
创建spring-data-jpa的测试案例
完成了Spring D
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