环境搭建:

步骤:1.引入坐标;2.配置spring的配置文件(整合jpa);3.编写实体类,使用 jpa 注解配置映射关系;4.编写dao层接口;5. 简单测试分析。

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1. pom文件配置:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>cn.itcast</groupId>
    <artifactId>jpa-day2</artifactId>
    <version>1.0-SNAPSHOT</version>

    <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 -->
        <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>

</project>

2. 配置spring 配置文件(整合jpa):applicationContext.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"
       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">

    <!--spring 和 spring data jpa的配置-->

    <!-- 1.创建entityManagerFactory对象交给spring容器管理-->
    <bean id="entityManagerFactoty" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <!--配置的扫描的包(实体类所在的包) -->
        <property name="packagesToScan" value="cn.hcc.domain" />
        <!-- 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">
                <!--配置是否自动创建数据库表 -->
                <property name="generateDdl" value="false" />
                <!--指定数据库类型 -->
                <property name="database" value="MYSQL" />
                <!--数据库方言:支持的特有语法 -->
                <property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect" />
                <!--是否显示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>

    <!--2.创建数据库连接池 -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="user" value="root"></property>
        <property name="password" value="root"></property>
        <property name="jdbcUrl" value="jdbc:mysql:///springdatajpa" ></property>
        <property name="driverClass" value="com.mysql.jdbc.Driver"></property>
    </bean>

    <!--3.整合spring dataJpa-->
    <jpa:repositories base-package="cn.itcast.dao" transaction-manager-ref="transactionManager"
                   entity-manager-factory-ref="entityManagerFactoty" ></jpa:repositories>

    <!--4.配置事务管理器 -->
    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactoty"></property>
    </bean>

    <!-- 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(* cn.hcc.service.*.*(..))" />
        <aop:advisor advice-ref="txAdvice" pointcut-ref="pointcut" />
    </aop:config>


    <!--5.声明式事务 -->

    <!-- 6. 配置包扫描-->
    <context:component-scan base-package="cn.hcc" ></context:component-scan>
</beans>

3.编写实体类,使用 jpa 注解配置映射关系:

package cn.hcc.domain;

import javax.persistence.*;

/**
 * 客户的实体类
 *      配置映射关系
 *
 *
 *   1.实体类和表的映射关系
 *      @Entity:声明实体类
 *      @Table : 配置实体类和表的映射关系
 *          name : 配置数据库表的名称
 *   2.实体类中属性和表中字段的映射关系
 *
 *
 */
@Entity
@Table(name = "cst_customer")
public class Customer {

    /**
     * @Id:声明主键的配置
     * @GeneratedValue:配置主键的生成策略
     *      strategy
     *          GenerationType.IDENTITY :自增,mysql
     *                 * 底层数据库必须支持自动增长(底层数据库支持的自动增长方式,对id自增)
     *          GenerationType.SEQUENCE : 序列,oracle
     *                  * 底层数据库必须支持序列
     *          GenerationType.TABLE : jpa提供的一种机制,通过一张数据库表的形式帮助我们完成主键自增
     *          GenerationType.AUTO : 由程序自动的帮助我们选择主键生成策略
     * @Column:配置属性和字段的映射关系
     *      name:数据库表中字段的名称
     */
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "cust_id")
    private Long custId; //客户的主键

    @Column(name = "cust_name")
    private String custName;//客户名称

    @Column(name="cust_source")
    private String custSource;//客户来源

    @Column(name="cust_level")
    private String custLevel;//客户级别

    @Column(name="cust_industry")
    private String custIndustry;//客户所属行业

    @Column(name="cust_phone")
    private String custPhone;//客户的联系方式

    @Column(name="cust_address")
    private String custAddress;//客户地址

    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 getCustLevel() {
        return custLevel;
    }

    public void setCustLevel(String custLevel) {
        this.custLevel = custLevel;
    }

    public String getCustIndustry() {
        return custIndustry;
    }

    public void setCustIndustry(String custIndustry) {
        this.custIndustry = custIndustry;
    }

    public String getCustPhone() {
        return custPhone;
    }

    public void setCustPhone(String custPhone) {
        this.custPhone = custPhone;
    }

    public String getCustAddress() {
        return custAddress;
    }

    public void setCustAddress(String custAddress) {
        this.custAddress = custAddress;
    }

    @Override
    public String toString() {
        return "Customer{" +
                "custId=" + custId +
                ", custName='" + custName + '\'' +
                ", custSource='" + custSource + '\'' +
                ", custLevel='" + custLevel + '\'' +
                ", custIndustry='" + custIndustry + '\'' +
                ", custPhone='" + custPhone + '\'' +
                ", custAddress='" + custAddress + '\'' +
                '}';
    }
}

 4.dao接口编写:不需要写任何东西就可以做一些简单的增删改查;

/**
 * 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> {

}

5.进行方法的测试:

package cn.hcc.test;

import cn.hcc.dao.CustomerDao;
import cn.hcc.domain.Customer;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

@RunWith(SpringJUnit4ClassRunner.class) //声明spring提供的单元测试环境
@ContextConfiguration(locations = "classpath:applicationContext.xml")//指定spring容器的配置信息
public class CustomerDaoTest {
    @Autowired
    private CustomerDao customerDao;

    /**
     * 根据id查询
     */
    @Test
    public void testFindOne() {
        Customer customer = customerDao.findOne(4l);
        System.out.println(customer);
    }

    /**
     * save : 保存或者更新
     *      根据传递的对象是否存在主键id,
     *      如果没有id主键属性:保存
     *      存在id主键属性,根据id查询数据,更新数据
     */
    @Test
    public void testSave() {
        Customer customer  = new Customer();
        customer.setCustName("hcc");
        customer.setCustLevel("vip");
        customer.setCustIndustry("it学习");
        customerDao.save(customer);
    }

    @Test
    public void testUpdate() {
        Customer customer  = new Customer();
        customer.setCustId(4l);
        customer.setCustName("hcc很厉害");
        customerDao.save(customer);
    }

    @Test
    public void testDelete () {
        customerDao.delete(3l);
    }


    /**
     * 查询所有
     */
    @Test
    public void testFindAll() {
        List<Customer> list = customerDao.findAll();
        for(Customer customer : list) {
            System.out.println(customer);
        }
    }

    /**
     * 测试统计查询:查询客户的总数量
     *      count:统计总条数
     */
    @Test
    public void testCount() {
        long count = customerDao.count();//查询全部的客户数量
        System.out.println(count);
    }

    /**
     * 测试:判断id为4的客户是否存在
     *      1. 可以查询以下id为4的客户
     *          如果值为空,代表不存在,如果不为空,代表存在
     *      2. 判断数据库中id为4的客户的数量
     *          如果数量为0,代表不存在,如果大于0,代表存在
     */
    @Test
    public void  testExists() {
        boolean exists = customerDao.exists(4l);
        System.out.println("id为4的客户 是否存在:"+exists);
    }


    /**
     * 根据id从数据库查询
     *      @Transactional : 保证getOne正常运行
     *
     *  findOne:
     *      em.find()           :立即加载
     *  getOne:
     *      em.getReference     :延迟加载
     *      * 返回的是一个客户的动态代理对象
     *      * 什么时候用,什么时候查询
     */
    @Test
    @Transactional
    public void  testGetOne() {
        Customer customer = customerDao.getOne(4l);
        System.out.println(customer);
    }

}

 

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