Spring Data JPA快速入门案例,Spring整合Spring Data JPA配置文件约束

Spring Data JPA快速入门案例流程：

一：搭建环境

1、创建maven工程

2、导入所需jar包坐标

3、配置Spring的applicationContext.xml配置文件，整合Spring Data JPA

4、创建实体类domain文件，使用jpa注解配置映射关系(实体类与数据表、实体类属性和数据表字段)

二、编写接口和测试

5、编写符合Spring Data JPA的dao层接口文件，该接口需要继承JpaRepository接口和JpaSpecificationExecutor

6、编写测试类，进行测试；findOne(查询一条数据)、save(新增或更新)、delete(删除一条)

三、实现流程图解

1、创建maven工程：略，大家可以自行创建

2、导入所需jar包坐标

<properties>
        <spring.version>5.0.2.RELEASE</spring.version>
        <hibernate.version>5.0.7.Final</hibernate.version>
        <s1f4j.version>1.6.6</s1f4j.version>
        <log4j.version>1.2.12</log4j.version>
        <c3pe.version>0.9.1.2</c3pe.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>${c3pe.version}</version>
        </dependency>

        <!--log end-->

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>${log4j.version}</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>${s1f4j.version}</version>
        </dependency>
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>${s1f4j.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>

        <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.3.0</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-impl</artifactId>
            <version>2.3.0</version>
        </dependency>
        <dependency>
            <groupId>com.sun.xml.bind</groupId>
            <artifactId>jaxb-core</artifactId>
            <version>2.3.0</version>
        </dependency>
        <dependency>
            <groupId>javax.activation</groupId>
            <artifactId>activation</artifactId>
            <version>1.1.1</version>
        </dependency>
    </dependencies>

3、配置Spring的applicationContext.xml配置文件，整合Spring Data JPA(从网上看别人的文章，很多都不带xml文件的约束，这也是很多人经常遇到坑的地方，我这里把整个文件都贴出来，包名、数据库信息大家根据自己的情况修改)

<?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="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <!--配置数据源连接池-->
        <property name="dataSource" ref="dataSource"/>

        <!--配置扫描实体类所在的包-->
        <property name="packagesToScan" value="cn.gpxxg.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（不同数据库有不同的语法）-->
                <property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect"/>
                <!--是否显示sql-->
                <property name="showSql" value="true"/>
            </bean>
        </property>

        <!--jpa方言:可使用HibernateJpa的高级特性-->
        <property name="jpaDialect">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect"/>
        </property>
    </bean>

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

    <!--3 spring整个spring data jpa-->
    <jpa:repositories base-package="cn.gpxxg.dao" transaction-manager-ref="transactionManager"
                      entity-manager-factory-ref="entityManagerFactory"></jpa:repositories>

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

    <!--5 声明式事务-->

    <!--6 扫描包配置-->
    <context:component-scan base-package="cn.gpxxg"></context:component-scan>

</beans>

4、创建实体类domain文件，使用jpa注解配置映射关系(实体类与数据表、实体类属性和数据表字段)

CREATE TABLE `customer` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `cust_name` varchar(255) DEFAULT NULL COMMENT '客户名称',
  `cust_source` varchar(255) DEFAULT NULL COMMENT '客户来源',
  `cust_level` varchar(255) DEFAULT NULL COMMENT '客户级别',
  `cust_industry` varchar(255) DEFAULT NULL COMMENT '客户所属行业',
  `cust_phone` varchar(255) DEFAULT NULL COMMENT '客户电话',
  `cust_address` varchar(255) DEFAULT NULL COMMENT '客户地址',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='客户表';

package cn.gpxxg.domain;

import javax.persistence.*;

@Entity // 将对象标记为JPA管理的实体
@Table(name = "customer")
public class Customer {

    @Id // 标明是主键
    @GeneratedValue(strategy = GenerationType.IDENTITY) // 主键的自增方式
    @Column(name = "id") // 与数据库的字段名对应起来
    private Long id;             // id

    @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;    // 客户电话

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

    public Customer() {
    }

    public Customer(Long id, String custName, String custSource, String custLevel, String custIndustry, String custPhone, String custAddress) {
        this.id = id;
        this.custName = custName;
        this.custSource = custSource;
        this.custLevel = custLevel;
        this.custIndustry = custIndustry;
        this.custPhone = custPhone;
        this.custAddress = custAddress;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    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{" +
                "id=" + id +
                ", custName='" + custName + '\'' +
                ", custSource='" + custSource + '\'' +
                ", custLevel='" + custLevel + '\'' +
                ", custIndustry='" + custIndustry + '\'' +
                ", custPhone='" + custPhone + '\'' +
                ", custAddress='" + custAddress + '\'' +
                '}';
    }
}

5、编写符合Spring Data JPA的dao层接口文件，该接口需要继承JpaRepository接口和JpaSpecificationExecutor

package cn.gpxxg.dao;

import cn.gpxxg.domain.Customer;
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.util.List;

/**
 * 该dao接口需要继承两个接口
 * JpaRepository<T, ID> 该接口实现了基本的数据查询
 *     T：实体类
 *     ID：实体类主键的数据类型
 * JpaSpecificationExecutor<T> 该接口实现了复杂的数据查询(分页)
 *     T：实体类
 */
public interface ICustomerDao extends JpaRepository<Customer, Long>, JpaSpecificationExecutor<Customer> {
    @Query("from Customer where custName = ?")
    Customer getByCustName(String custName);

    /**
     * @Modifying 注解告知程序改方法是用于执行update更新的
     * 通配符?后的数字代表该通配符跟哪个参数匹配
     */
    @Query("update Customer set custName = ?2 where id = ?1")
    @Modifying
    void updateCustomer(Long id, String custName);

    /**
     * spring data jpa不仅支持jpql语句，也同样支持原生的sql语句
     * 使用sql语句查询同样需要使用到@Query注解，但是需要在注解的nativeQuery中告知使用的本地查询还是jpql查询
     *      nativeQuery
     *          false：默认值，使用jpql语句查询
     *          true：使用本地查询，也就是使用sql语句查询
     *
     */
    @Query(value = "select * from customer where cust_name like ?1", nativeQuery = true)
    List<Object[]> findBySql(String custName);

    /**
     * spring data jpa不仅可以使用dao层生成的代理对象中提供的默认方法进行查询(findOne、findAll、delete、save等)和jpql/sql查询
     * 还可以使用方法命名规则进行查询，规则是：findBy + 属性名称 + 模糊查询(Like/isnull),底层会自动把整个方法名翻译为sql语句select * from table where 属性名 = ?
     */
    List<Customer> findByCustName(String custName);

    /**
     * 如要根据custAddress迷糊查询并且custName精准查询，则把方法名定义为findByCustAddressLikeAndCustName(String custAddress, String custName)
     * 注意：
     *      1、这里的参数必须和定义时的属性名顺序一致，不能使用通配符匹配了
     *      2、使用方法命名规则进行查询，不需要使用注解
     */
    List<Customer> findByCustAddressLikeAndCustName(String custAddress, String custName);
}

6、编写测试类，进行测试；findOne(查询一条数据)、save(新增或更新)、delete(删除一条)、findAll(查找所有)

package cn.gpxxg.test;

import cn.gpxxg.dao.ICustomerDao;
import cn.gpxxg.domain.Customer;
import org.hibernate.jpa.internal.schemagen.ScriptTargetOutputToFile;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.annotation.Rollback;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.transaction.annotation.Transactional;

import java.lang.reflect.Array;
import java.util.Arrays;
import java.util.List;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:applicationContext.xml")
public class CustomerTest {

    @Autowired
    private ICustomerDao dao;

    /**
     * findOne：根据id查找一条数据
     */
    @Test
    public void testFindOne()
    {
        Customer customer = dao.findOne(2L);
        System.out.println(customer);
    }


    /**
     * save：新增或更新数据(取决于对象中是否有主键id)
     */
    @Test
    public void testAdd()
    {
        Customer customer = new Customer();
        customer.setCustName("马德华");
        customer.setCustAddress("西游记");
        dao.save(customer);
    }


    /**
     * save：新增或更新数据(取决于对象中是否有主键id)
     */
    @Test
    public void testUpdate()
    {
        Customer customer = dao.findOne(1L);
        customer.setCustName("我更新的客户名称");
        customer.setCustAddress("上海");
        dao.save(customer);
    }


    /**
     * delete：删除数据
     */
    @Test
    public void testDelete()
    {
        dao.delete(2L);
    }


    /**
     * delete：删除数据
     */
    @Test
    public void testFindAll()
    {
        List<Customer> list = dao.findAll();
        for (Customer customer : list) {
            System.out.println(customer);
        }
    }


    /**
     * count:获取表中数据量条数
     */
    @Test
    public void testCount()
    {
        long count = dao.count();
        System.out.println(count);
    }


    /**
     * exists:获取表中是否有id为1的数据
     */
    @Test
    public void testExists()
    {
        boolean flag = dao.exists(1L);
        System.out.println(flag);
    }


    /**
     * exists:获取表中是否有id为1的数据
     */
    @Test
    @Transactional
    public void testGetone()
    {
        Customer one = dao.getOne(1L);
        System.out.println(one);
    }


    /**
     * 测试jpql语句
     */
    @Test
    public void testJpql()
    {
        Customer customer = dao.getByCustName("你好啊");
        System.out.println(customer);
    }


    /**
     * 测试jpql语句:更新操作
     */
    @Test
    @Transactional
    @Rollback(false)
    public void testChange()
    {
        dao.updateCustomer(2L, "改一个名");
    }


    /**
     * 测试sql语句查询
     */
    @Test
    public void testSql()
    {
        List<Object[]> list = dao.findBySql("你%");
        for (Object[] objects : list) {
            System.out.println(Arrays.toString(objects));
        }
    }

    /**
     * 测试sql语句查询
     */
    @Test
    public void testfindByCustName()
    {
        List<Customer> list = dao.findByCustName("你明卫");
        for (Customer customer : list) {
            System.out.println(customer);
        }
    }


    @Test
    public void testLike()
    {
        List<Customer> list = dao.findByCustAddressLikeAndCustName("bei%", "改一个名");
        for (Customer customer : list) {
            System.out.println(customer);
        }
    }

}

三、实现流程图解