環境搭建:
步驟:1.引入坐標;2.配置spring的配置文件(整合jpa);3.編寫實體類,使用 jpa 注解配置映射關系;4.編寫dao層接口;5. 簡單測試分析。
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單元測試 --> <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>${spring.version}</version> </dependency> <!-- spring對orm框架的支持包--> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> <version>${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>${mysql.version}</version> </dependency> <!-- spring data jpa 的坐標--> <dependency> <groupId>org.springframework.data</groupId> <artifactId>spring-data-jpa</artifactId> <version>1.9.0.RELEASE</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>${spring.version}</version> </dependency> <!-- el beg 使用spring data jpa 必須引入 --> <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.創建entityManagerFactory對象交給spring容器管理--> <bean id="entityManagerFactoty" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> <property name="dataSource" ref="dataSource" /> <!--配置的掃描的包(實體類所在的包) --> <property name="packagesToScan" value="cn.hcc.domain" /> <!-- jpa的實現廠家 --> <property name="persistenceProvider"> <bean class="org.hibernate.jpa.HibernatePersistenceProvider"/> </property> <!--jpa的供應商適配器 --> <property name="jpaVendorAdapter"> <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"> <!--配置是否自動創建數據庫表 --> <property name="generateDdl" value="false" /> <!--指定數據庫類型 --> <property name="database" value="MYSQL" /> <!--數據庫方言:支持的特有語法 --> <property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect" /> <!--是否顯示sql --> <property name="showSql" value="true" /> </bean> </property> <!--jpa的方言 :高級的特性 --> <property name="jpaDialect" > <bean class="org.springframework.orm.jpa.vendor.HibernateJpaDialect" /> </property> </bean> <!--2.創建數據庫連接池 --> <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.配置事務管理器 --> <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.聲明式事務 --> <!-- 6. 配置包掃描--> <context:component-scan base-package="cn.hcc" ></context:component-scan> </beans>
3.編寫實體類,使用 jpa 注解配置映射關系:
package cn.hcc.domain; import javax.persistence.*; /** * 客戶的實體類 * 配置映射關系 * * * 1.實體類和表的映射關系 * @Entity:聲明實體類 * @Table : 配置實體類和表的映射關系 * name : 配置數據庫表的名稱 * 2.實體類中屬性和表中字段的映射關系 * * */ @Entity @Table(name = "cst_customer") public class Customer { /** * @Id:聲明主鍵的配置 * @GeneratedValue:配置主鍵的生成策略 * strategy * GenerationType.IDENTITY :自增,mysql * * 底層數據庫必須支持自動增長(底層數據庫支持的自動增長方式,對id自增) * GenerationType.SEQUENCE : 序列,oracle * * 底層數據庫必須支持序列 * GenerationType.TABLE : jpa提供的一種機制,通過一張數據庫表的形式幫助我們完成主鍵自增 * GenerationType.AUTO : 由程序自動的幫助我們選擇主鍵生成策略 * @Column:配置屬性和字段的映射關系 * name:數據庫表中字段的名稱 */ @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name = "cust_id") private Long custId; //客戶的主鍵 @Column(name = "cust_name") private String custName;//客戶名稱 @Column(name="cust_source") private String custSource;//客戶來源 @Column(name="cust_level") private String custLevel;//客戶級別 @Column(name="cust_industry") private String custIndustry;//客戶所屬行業 @Column(name="cust_phone") private String custPhone;//客戶的聯系方式 @Column(name="cust_address") private String custAddress;//客戶地址 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接口編寫:不需要寫任何東西就可以做一些簡單的增刪改查;
/** * 符合SpringDataJpa的dao層接口規范 * JpaRepository<操作的實體類類型,實體類中主鍵屬性的類型> * * 封裝了基本CRUD操作 * JpaSpecificationExecutor<操作的實體類類型> * * 封裝了復雜查詢(分頁) */ public interface CustomerDao extends JpaRepository<Customer,Long> ,JpaSpecificationExecutor<Customer> { }
5.進行方法的測試:
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) //聲明spring提供的單元測試環境 @ContextConfiguration(locations = "classpath:applicationContext.xml")//指定spring容器的配置信息 public class CustomerDaoTest { @Autowired private CustomerDao customerDao; /** * 根據id查詢 */ @Test public void testFindOne() { Customer customer = customerDao.findOne(4l); System.out.println(customer); } /** * save : 保存或者更新 * 根據傳遞的對象是否存在主鍵id, * 如果沒有id主鍵屬性:保存 * 存在id主鍵屬性,根據id查詢數據,更新數據 */ @Test public void testSave() { Customer customer = new Customer(); customer.setCustName("hcc"); customer.setCustLevel("vip"); customer.setCustIndustry("it學習"); customerDao.save(customer); } @Test public void testUpdate() { Customer customer = new Customer(); customer.setCustId(4l); customer.setCustName("hcc很厲害"); customerDao.save(customer); } @Test public void testDelete () { customerDao.delete(3l); } /** * 查詢所有 */ @Test public void testFindAll() { List<Customer> list = customerDao.findAll(); for(Customer customer : list) { System.out.println(customer); } } /** * 測試統計查詢:查詢客戶的總數量 * count:統計總條數 */ @Test public void testCount() { long count = customerDao.count();//查詢全部的客戶數量 System.out.println(count); } /** * 測試:判斷id為4的客戶是否存在 * 1. 可以查詢以下id為4的客戶 * 如果值為空,代表不存在,如果不為空,代表存在 * 2. 判斷數據庫中id為4的客戶的數量 * 如果數量為0,代表不存在,如果大於0,代表存在 */ @Test public void testExists() { boolean exists = customerDao.exists(4l); System.out.println("id為4的客戶 是否存在:"+exists); } /** * 根據id從數據庫查詢 * @Transactional : 保證getOne正常運行 * * findOne: * em.find() :立即加載 * getOne: * em.getReference :延遲加載 * * 返回的是一個客戶的動態代理對象 * * 什么時候用,什么時候查詢 */ @Test @Transactional public void testGetOne() { Customer customer = customerDao.getOne(4l); System.out.println(customer); } }