• SpringData_01_SpringData的快速入门


    1.1SpringData JPA概述

    Spring Data JPA 是 Spring 基于 ORM 框架、JPA 规范的基础上封装的一套JPA应用框架,可使开发者用极简的代码即可实现对数据库的访问和操作。它提供了包括增删改查等在内的常用功能,且易于扩展!学习并使用 Spring Data JPA 可以极大提高开发效率!

    1.2Spring Data JPA 与 JPA和hibernate之间的关系

    JPA是一套规范,内部是有接口和抽象类组成的。hibernate是一套成熟的ORM框架,而且Hibernate实现了JPA规范,所以也可以称hibernate为JPA的一种实现方式,我们使用JPA的API编程,意味着站在更高的角度上看待问题(面向接口编程)

    2.1  Spring Data JPA的快速入门

    2.2  引入Spring Data JPA的坐标

    使用Spring Data JPA,需要整合Spring与Spring Data JPA,并且需要提供JPA的服务提供者hibernate,所以需要导入spring相关坐标,hibernate坐标,数据库驱动坐标等

    <properties>
            <spring.version>5.0.2.RELEASE</spring.version>
            <hibernate.version>5.0.7.Final</hibernate.version>
            <slf4j.version>1.6.6</slf4j.version>
            <log4j.version>1.2.12</log4j.version>
            <c3p0.version>0.9.1.2</c3p0.version>
            <mysql.version>5.1.6</mysql.version>
        </properties>
    
        <dependencies>
            <!-- junit单元测试 -->
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
                <scope>test</scope>
            </dependency>
    
            <!-- spring beg  AOP-->
            <dependency>
                <groupId>org.aspectj</groupId>
                <artifactId>aspectjweaver</artifactId>
                <version>1.6.8</version>
            </dependency>
    
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-aop</artifactId>
                <version>${spring.version}</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>
    
            <!-- 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>
    
            <!-- spring end -->
    
            <!-- hibernate beg -->
            <dependency>
                <groupId>org.hibernate</groupId>
                <artifactId>hibernate-core</artifactId>
                <version>${hibernate.version}</version>
            </dependency>
            <dependency>
                <groupId>org.hibernate</groupId>
                <artifactId>hibernate-entitymanager</artifactId>
                <version>${hibernate.version}</version>
            </dependency>
            <dependency>
                <groupId>org.hibernate</groupId>
                <artifactId>hibernate-validator</artifactId>
                <version>5.2.1.Final</version>
            </dependency>
            <!-- hibernate end -->
    
            <!-- c3p0 beg -->
            <dependency>
                <groupId>c3p0</groupId>
                <artifactId>c3p0</artifactId>
                <version>${c3p0.version}</version>
            </dependency>
            <!-- c3p0 end -->
    
            <!-- log end -->
            <dependency>
                <groupId>log4j</groupId>
                <artifactId>log4j</artifactId>
                <version>${log4j.version}</version>
            </dependency>
    
            <dependency>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-api</artifactId>
                <version>${slf4j.version}</version>
            </dependency>
    
            <dependency>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-log4j12</artifactId>
                <version>${slf4j.version}</version>
            </dependency>
            <!-- log end -->
    
    
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>${mysql.version}</version>
            </dependency>
    
            <!-- spring data jpa 的坐标-->
            <dependency>
                <groupId>org.springframework.data</groupId>
                <artifactId>spring-data-jpa</artifactId>
                <version>1.9.0.RELEASE</version>
            </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>2.2.4</version>
            </dependency>
    
            <dependency>
                <groupId>org.glassfish.web</groupId>
                <artifactId>javax.el</artifactId>
                <version>2.2.4</version>
            </dependency>
            <!-- el end -->
        </dependencies>

    2.3 整合Spring Data JPA与Spring

    <?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"
           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">
    
        <!-- 1.dataSource 配置数据库连接池-->
        <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
            <property name="driverClass" value="com.mysql.jdbc.Driver"/>
            <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/test"/>
            <property name="user" value="root"/>
            <property name="password" value="12345"/>
        </bean>
    
        <!-- 2.配置entityManagerFactory 对象交给spring容器来管理-->
        <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
            <property name="dataSource" ref="dataSource"/>
            <!--配置要扫描的包(实体类所在的包)-->
            <property name="packagesToScan" value="com.hdh.entity"/>
            <!--jpa的实现厂家-->
            <property name="persistenceProvider">
                <bean class="org.hibernate.jpa.HibernatePersistenceProvider"/>
            </property>
            <!--JPA的供应商适配器-->
            <property name="jpaVendorAdapter">
                <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
                    <!--是否自动创建表-->
                    <property name="generateDdl" value="false"/>
                    <!--指定数据库的类型-->
                    <property name="database" value="MYSQL"/>
                    <!--数据库方言  支持的数据库语法-->
                    <property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect"/>
                    <!--控制台是否显示打印sql-->
                    <property name="showSql" value="true"/>
                </bean>
            </property>
            <!--jpa的方言:高级的特性-->
            <property name="jpaDialect">
                <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect"/>
            </property>
        </bean>
    
    
        <!-- 3.事务管理器-->
        <!-- JPA事务管理器  -->
        <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
            <property name="entityManagerFactory" ref="entityManagerFactory"/>
        </bean>
    
        <!-- 整合spring data jpa-->
        <jpa:repositories base-package="com.hdh.dao"
                          transaction-manager-ref="transactionManager"
                          entity-manager-factory-ref="entityManagerFactory"></jpa:repositories>
    
        <!-- 4.txAdvice-->
        <tx:advice id="txAdvice" transaction-manager="transactionManager">
            <tx:attributes>
                <tx:method name="save*" propagation="REQUIRED"/>
                <tx:method name="insert*" propagation="REQUIRED"/>
                <tx:method name="update*" propagation="REQUIRED"/>
                <tx:method name="delete*" propagation="REQUIRED"/>
                <tx:method name="get*" read-only="true"/>
                <tx:method name="find*" read-only="true"/>
                <tx:method name="*" propagation="REQUIRED"/>
            </tx:attributes>
        </tx:advice>
    
        <!-- 5.aop-->
        <aop:config>
            <aop:pointcut id="pointcut" expression="execution(* com.hdh.service.*.*(..))"/>
            <aop:advisor advice-ref="txAdvice" pointcut-ref="pointcut"/>
        </aop:config>
    
        <context:component-scan base-package="com.hdh"></context:component-scan>
    
        <!--组装其它 配置文件-->
    
    </beans>

    2.4使用JPA注解配置映射关系

    @Entity //声明实体类
    @Table(name = "cst_customer") //建立实体类和表的映射关系
    public class Customer {
    
        @Id//声明当前私有属性为主键
        @GeneratedValue(strategy = GenerationType.IDENTITY) //配置主键的生成策略
        @Column(name = "cust_id") //指定和表中cust_id字段的映射关系
        private Long custId;
    
        @Column(name = "cust_name") //指定和表中cust_name字段的映射关系
        private String custName;
    
        @Column(name = "cust_source")//指定和表中cust_source字段的映射关系
        private String custSource;
    
        @Column(name = "cust_industry")//指定和表中cust_industry字段的映射关系
        private String custIndustry;
    
        @Column(name = "cust_level")//指定和表中cust_level字段的映射关系
        private String custLevel;
    
        @Column(name = "cust_address")//指定和表中cust_address字段的映射关系
        private String custAddress;
    
        @Column(name = "cust_phone")//指定和表中cust_phone字段的映射关系
        private String custPhone;
      //get set省略 }

    3.1  使用Spring Data JPA完成需求

    3.2编写符合Spring Data JPA规范的Dao层接口

    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
    /**
     * 符合SpringDataJpa的dao层接口规范
     * JpaRepository<操作的实体类类型,实体类中主键属性的类型>
     * * 封装了基本CRUD操作
     * JpaSpecificationExecutor<操作的实体类类型>
     * * 封装了复杂查询(分页)
     */
    public interface CustomerDao extends JpaRepository<Customer, Long>, JpaSpecificationExecutor<Customer> {
    
    }

    3.3完成基本CRUD操作

    完成了Spring Data JPA的环境搭建,并且编写了符合Spring Data JPA 规范的Dao层接口之后,就可以使用定义好的Dao层接口进行客户的基本CRUD操作

    //申明spring提供的单元测试环境
    @RunWith(SpringJUnit4ClassRunner.class)
    //指定加载spring容器
    @ContextConfiguration(locations = "classpath:applicationContext.xml")
    public class CustomerDaoTest {
    
        @Autowired
        private CustomerDao customerDao;
    
        /**
         * 根据id查询
         */
        @Test
        public void testFindOne() {
            Customer customer = customerDao.findOne(1L);
            System.out.println(customer);
        }
    
        /**
         * 保存或者更新
         * 根据你传入的对象是否存在主键 存在:则是更新
         *                              不存:在则是保存
         *jap在保存或者更新  会先发送一条查询语句
         */
    
        @Test
        public void testSave() {
            Customer customer = new Customer();
            customer.setCustId(2l);
            customer.setCustName("xj");
            Customer save = customerDao.save(customer);
            System.out.println(save);
        }
    
        @Test
        public void testUpdate() {
            Customer customer = new Customer();
            customer.setCustId(2l);
            customer.setCustName("xj11");
            Customer save = customerDao.save(customer);
            System.out.println(save);
        }
    
        /**
         * ge根据id删除
         */
        @Test
        public void testDelete() {
             customerDao.delete(2l);
        }
    
        /**
         * ge根据id删除
         */
        @Test
        public void testSelectAll() {
            List<Customer> customers= customerDao.findAll();
            customers.forEach(System.out::println);
    
        }
    
    
    }

     

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  • 原文地址:https://www.cnblogs.com/asndxj/p/11801918.html
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