SpringData JPA实现基本的crud

待我称王封你为后i 2023-06-30 11:57 26阅读 0赞

# 搭建环境 #

## 创建工程引入坐标 ##

1、创建一个不选择骨架的maven工程  
2、引入坐标  
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>4.2.4.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>8.0.15</mysql.version>
        </properties>
    
        <dependencies>
            
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.9</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>${c3p0.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>${slf4j.version}</version>
            </dependency>
    
            <dependency>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-log4j12</artifactId>
                <version>${slf4j.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> 
            
        </dependencies>

## 配置spring文件 ##

1、在resource下创建一个spring配置文件applicationContext.xml：将容器交给spring管

<?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="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
            <property name="driverClass" value="com.mysql.cj.jdbc.Driver"/>
            <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/test?serverTimezone=UTC"/>
            <property name="user" value="root"/>
            <property name="password" value="123456"/>
        </bean>
    
        
        <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
            <property name="dataSource" ref="dataSource"/>
            
            <property name="packagesToScan" value="com.oceanstar.entity"/>
            
            <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 id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
            <property name="entityManagerFactory" ref="entityManagerFactory"/>
        </bean>
    
        
        <jpa:repositories base-package="com.oceanstar.dao"
                          transaction-manager-ref="transactionManager"
                          entity-manager-factory-ref="entityManagerFactory"></jpa:repositories>
    
        
        <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>
    
        
        <aop:config>
            <aop:pointcut id="pointcut" expression="execution(* com.oceanstar.service.*.*(..))"/>
            <aop:advisor advice-ref="txAdvice" pointcut-ref="pointcut"/>
        </aop:config>
    
        <context:component-scan base-package="com.oceanstar"></context:component-scan>
    
        
    
    </beans>

## 创建实体类&使用jpa注解配置映射关系 ##

package com.oceanstar.entity;
    
    
    import javax.persistence.Column;
    import javax.persistence.Entity;
    import javax.persistence.GeneratedValue;
    import javax.persistence.GenerationType;
    import javax.persistence.Id;
    import javax.persistence.Table;
    
    /**
     *
     *      * 所有的注解都是使用JPA的规范提供的注解，
     *      * 所以在导入注解包的时候，一定要导入javax.persistence下的
     */
    @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;
    
        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;
        }
    }

# 使用Spring Data JPA完成需求 #

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**

![在这里插入图片描述][20200117154626915.png]

package com.oceanstar.dao;
    
    
    import com.oceanstar.entity.Customer;
    import org.springframework.data.jpa.repository.JpaRepository;
    import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
    
    /**
     * 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> {
        
    }

这样我们就定义好了一个符合Spring Data JPA规范的Dao层接口

## 完成基本的CRUD操作 ##

JpaRepository中已经实现类一些dao方法，我们直接调用即可

package com.oceanstar.test;
    
    
    import com.oceanstar.dao.CustomerDao;
    import com.oceanstar.entity.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;
    
    @RunWith(SpringJUnit4ClassRunner.class)
    @ContextConfiguration(locations = "classpath:applicationContext.xml")
    public class CustomerDaoTest {
        
    
        @Autowired
        private CustomerDao customerDao;
    
        /*
        * 根据id查询
        * */
        @Test
        public void testFindoById(){
        
            Customer customer = customerDao.findOne(8l);
            System.out.println(customer);
        }
    
        /**
         * save:根据传递的对象是否存在主键id，保存/更新操作
         *          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 c = new Customer();
            c.setCustName("传智播客");
            customerDao.save(c);
        }
    
        @Test
        public void testUpdate() {
        
            //根据id查询id为1的客户
            Customer customer = customerDao.findOne(2l);
            //修改客户名称
            customer.setCustName("---~~~~顺义校区");
            //更新
            customerDao.save(customer);
        }
    
        /**
         * 根据id删除：调用delete(id)方法
         */
        @Test
        public void testDelete() {
        
            customerDao.delete(2l);
        }
    }

[20200117154626915.png]: https://img-blog.csdnimg.cn/20200117154626915.png