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

曾经终败给现在 2023-01-20 04:59 112阅读 0赞

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>
    
            
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
                <scope>test</scope>
            </dependency>
    
            
            <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>
            
            <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>
    
            
    
            
            <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>
    
            
    
            
            <dependency>
                <groupId>c3p0</groupId>
                <artifactId>c3p0</artifactId>
                <version>${c3pe.version}</version>
            </dependency>
    
            
    
            <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>
            
    
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>${mysql.version}</version>
            </dependency>
    
            
            <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>
    
            
            <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">
    
        
    
        
        <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
            
            <property name="dataSource" ref="dataSource"/>
    
            
            <property name="packagesToScan" value="cn.gpxxg.domain"/>
    
            
            <property name="persistenceProvider">
                <bean class="org.hibernate.jpa.HibernatePersistenceProvider"/>
            </property>
    
            
            <property name="jpaVendorAdapter">
                <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
                    
                    <property name="generateDdl" value="false"/>
                    
                    <property name="database" value="MYSQL"/>
                    
                    <property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect"/>
                    
                    <property name="showSql" value="true"/>
                </bean>
            </property>
    
            
            <property name="jpaDialect">
                <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect"/>
            </property>
        </bean>
    
        
        <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>
    
        
        <jpa:repositories base-package="cn.gpxxg.dao" transaction-manager-ref="transactionManager"
                          entity-manager-factory-ref="entityManagerFactory"></jpa:repositories>
    
        
        <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
            <property name="entityManagerFactory" ref="entityManagerFactory"></property>
        </bean>
    
        
    
        
        <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

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMzMDg4ODA3_size_16_color_FFFFFF_t_70][]

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