环境搭建
导入依赖 maven3.6.3
<properties>
<spring.version>5.2.5.RELEASE</spring.version>
<hibernate.version>5.4.10.Final</hibernate.version>
<slf4j.version>1.7.30</slf4j.version>
<log4j.version>2.12.1</log4j.version>
<druid.version>1.1.21</druid.version>
<mysql.version>5.1.6</mysql.version>
</properties>
<dependencies>
<!-- spring beg -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aop</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.9.5</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${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>${spring.version}</version>
</dependency>
<!-- hibernate beg -->
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>${hibernate.version}</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>${hibernate.version}</version>
</dependency>
<dependency>
<groupId>org.hibernate.validator</groupId>
<artifactId>hibernate-validator</artifactId>
<version>6.1.2.Final</version>
<exclusions>
<exclusion>
<artifactId>classmate</artifactId>
<groupId>com.fasterxml</groupId>
</exclusion>
</exclusions>
</dependency>
<!-- hibernate end -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${mysql.version}</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>${druid.version}</version>
</dependency>
<!-- spring data jpa 的坐标 -->
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<version>2.2.6.RELEASE</version>
<exclusions>
<exclusion>
<artifactId>slf4j-api</artifactId>
<groupId>org.slf4j</groupId>
</exclusion>
</exclusions>
</dependency>
<!-- el beg 使用spring data jpa 必须引入 -->
<dependency>
<groupId>javax.el</groupId>
<artifactId>javax.el-api</artifactId>
<version>3.0.0</version>
</dependency>
<dependency>
<groupId>org.glassfish</groupId>
<artifactId>javax.el</artifactId>
<version>3.0.0</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${slf4j.version}</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>${log4j.version}</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
</dependencies>
编写配置文件
<?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" xmlns:contxt="http://www.springframework.org/schema/context" 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"><!-- 配置实体类管理工厂 --><bean id="entityManagerFactoryBean" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"><property name="dataSource" ref="dataSource"/><property name="packagesToScan" value="com.ytfs.entity"/><property name="persistenceProvider"><bean class="org.hibernate.jpa.HibernatePersistenceProvider"/></property><property name="jpaVendorAdapter"><bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"><property name="showSql" value="true"/><property name="database" value="MYSQL"/><property name="databasePlatform" value="org.hibernate.dialect.MySQLDialect"/><property name="generateDdl" value="false"/></bean></property></bean><!-- 配置事务管理器 --><bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"><property name="dataSource" ref="dataSource"/></bean><!-- 整合jpa --><jpa:repositories base-package="com.ytfs.dao" transaction-manager-ref="transactionManager" entity-manager-factory-ref="entityManagerFactoryBean"/><!-- spring的包扫描 --><context:component-scan base-package="com.ytfs"/><!-- 整合数据源 --><context:property-placeholder location="classpath:jdbcConfig.properties"/><bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"><property name="driverClassName" value="${jdbc.driver}"/><property name="username" value="${jdbc.username}"/><property name="password" value="${jdbc.password}"/><property name="url" value="${jdbc.url}"/></bean></beans>
实体类编写
注解说明
@OneToMany:
作用:建立一对多的关系映射
属性:
targetEntityClass:指定多的多方的类的字节码
mappedBy:指定从表实体类中引用主表对象的名称。
cascade:指定要使用的级联操作
fetch:指定是否采用延迟加载
orphanRemoval:是否使用孤儿删除
@ManyToOne
作用:建立多对一的关系
属性:
targetEntityClass:指定一的一方实体类字节码
cascade:指定要使用的级联操作
fetch:指定是否采用延迟加载
optional:关联是否可选。如果设置为false,则必须始终存在非空关系。
@JoinColumn
作用:用于定义主键字段和外键字段的对应关系。
属性:
name:指定外键字段的名称
referencedColumnName:指定引用主表的主键字段名称
unique:是否唯一。默认值不唯一
nullable:是否允许为空。默认值允许。
insertable:是否允许插入。默认值允许。
updatable:是否允许更新。默认值允许。
columnDefinition:列的定义信息。
Customer
package xyz.ytfs.entity;import org.springframework.test.context.ContextConfiguration;importjavax.persistence.*;import java.util.HashSet;import java.util.Set;/** * @Classname Customer
* @Description TODO(客户的实体类)
* @Date 2020/5/8 23:20
* @Created by ytfs
*/@Entity
@Table(name = "cst_customer")publicclass Customer {
/** * CREATE TABLE `cst_linkman` (
* `lkm_id` bigint(32) NOT NULL AUTO_INCREMENT COMMENT '联系人编号(主键)',
* `lkm_name` varchar(16) DEFAULT NULL COMMENT '联系人姓名',
* `lkm_gender` char(1) DEFAULT NULL COMMENT '联系人性别',
* `lkm_phone` varchar(16) DEFAULT NULL COMMENT '联系人办公电话',
* `lkm_mobile` varchar(16) DEFAULT NULL COMMENT '联系人手机',
* `lkm_email` varchar(64) DEFAULT NULL COMMENT '联系人邮箱',
* `lkm_position` varchar(16) DEFAULT NULL COMMENT '联系人职位',
* `lkm_memo` varchar(512) DEFAULT NULL COMMENT '联系人备注',
* `lkm_cust_id` bigint(32) NOT NULL COMMENT '客户id(外键)',
* PRIMARY KEY (`lkm_id`),
* KEY `FK_cst_linkman_lkm_cust_id` (`lkm_cust_id`),
* CONSTRAINT `FK_cst_linkman_lkm_cust_id` FOREIGN KEY (`lkm_cust_id`) REFERENCES `cst_customer` (`cust_id`) ON DELETE NO ACTION ON UPDATE NO ACTION
* ) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;
*/ @Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "cust_id")
private Long custId;
@Column(name = "cust_name")
private String custName;
@Column(name = "cust_source")
private String custSource;
@Column(name = "cust_industry")
private String custIndustry;
@Column(name = "cust_level")
private String custLevel;
@Column(name = "cust_address")
private String custAddress;
@Column(name = "cust_phone")
private String custPhone;
/* 表达一对多的关系
*//** * * 使用注解的形式配置多表关系
* 1.声明关系
* @OneToMany : 配置一对多关系
* targetEntity :对方对象的字节码对象
* 2.配置外键(中间表)
* @JoinColumn : 配置外键
* name:外键字段名称
* referencedColumnName:参照的主表的主键字段名称
*
* *在客户实体类上(一的一方)添加了外键了配置,所以对于客户而言,也具备了维护外键的作用
*///@OneToMany(targetEntity = LinkMan.class)
//@JoinColumn(name = "lkm_cust_id", referencedColumnName = "cust_id")/** * 放弃外键维护权
* mappedBy:对方配置关系的属性名称\ 这里就是值得LinkMan中Customer对象得变量名称
* cascade : 配置级联(可以配置到设置多表的映射关系的注解上)
* CascadeType.all : 所有
* MERGE :更新
* PERSIST :保存
* REMOVE :删除
* <p>
* fetch : 配置关联对象的加载方式
* EAGER :立即加载
* LAZY :延迟加载
*/ @OneToMany(mappedBy = "customer", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
privateSet linkMans =newHashSet<>();
public Long getCustId() {
return custId;
}
publicvoid setCustId(Long custId) {
this.custId = custId;
}
public String getCustName() {
return custName;
}
publicvoid setCustName(String custName) {
this.custName = custName;
}
public String getCustSource() {
return custSource;
}
publicvoid setCustSource(String custSource) {
this.custSource = custSource;
}
public String getCustIndustry() {
return custIndustry;
}
publicvoid setCustIndustry(String custIndustry) {
this.custIndustry = custIndustry;
}
public String getCustLevel() {
return custLevel;
}
publicvoid setCustLevel(String custLevel) {
this.custLevel = custLevel;
}
public String getCustAddress() {
return custAddress;
}
publicvoid setCustAddress(String custAddress) {
this.custAddress = custAddress;
}
public String getCustPhone() {
return custPhone;
}
publicvoid setCustPhone(String custPhone) {
this.custPhone = custPhone;
}
publicSet getLinkMans() {
return linkMans;
}
publicvoidsetLinkMans(Set linkMans) {
this.linkMans = linkMans;
}
@Override
public String toString() {
return"Customer{" + "custId=" + custId + ", custName='" + custName + '\'' + ", custSource='" + custSource + '\'' + ", custIndustry='" + custIndustry + '\'' + ", custLevel='" + custLevel + '\'' + ", custAddress='" + custAddress + '\'' + ", custPhone='" + custPhone + '\'' + '}';
}
}
LinkMan
package xyz.ytfs.entity;importjavax.persistence.*;/** * @Classname LinkMan
* @Description TODO(联系人的实体类)
* @Date 2020/5/8 23:16
* @Created by ytfs
*/@Entity
@Table(name = "cst_linkman")publicclass LinkMan {
/** * CREATE TABLE `cst_customer` (
* `cust_id` bigint(32) NOT NULL AUTO_INCREMENT COMMENT '客户编号(主键)',
* `cust_name` varchar(32) NOT NULL COMMENT '客户名称(公司名称)',
* `cust_source` varchar(32) DEFAULT NULL COMMENT '客户信息来源',
* `cust_industry` varchar(32) DEFAULT NULL COMMENT '客户所属行业',
* `cust_level` varchar(32) DEFAULT NULL COMMENT '客户级别',
* `cust_address` varchar(128) DEFAULT NULL COMMENT '客户联系地址',
* `cust_phone` varchar(64) DEFAULT NULL COMMENT '客户联系电话',
* PRIMARY KEY (`cust_id`)
* ) ENGINE=InnoDB AUTO_INCREMENT=94 DEFAULT CHARSET=utf8;
*/ @Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "lkm_id")
private Long lkmId;
@Column(name = "lkm_name")
private String lkmName;
@Column(name = "lkm_gender")
private String lkmGender;
@Column(name = "lkm_phone")
private String lkmPhone;
@Column(name = "lkm_mobile")
private String lkmMobile;
@Column(name = "lkm_email")
private String lkmEmail;
@Column(name = "lkm_position")
private String lkmPosition;
@Column(name = "lkm_memo")
private String lkmMemo;
/* 表达多对一的关系
*/ @ManyToOne(targetEntity = Customer.class)
@JoinColumn(name = "lkm_cust_id", referencedColumnName = "cust_id")
private Customer customer;
public Long getLkmId() {
return lkmId;
}
publicvoid setLkmId(Long lkmId) {
this.lkmId = lkmId;
}
public String getLkmName() {
return lkmName;
}
publicvoid setLkmName(String lkmName) {
this.lkmName = lkmName;
}
public String getLkmGender() {
return lkmGender;
}
publicvoid setLkmGender(String lkmGender) {
this.lkmGender = lkmGender;
}
public String getLkmPhone() {
return lkmPhone;
}
publicvoid setLkmPhone(String lkmPhone) {
this.lkmPhone = lkmPhone;
}
public String getLkmMobile() {
return lkmMobile;
}
publicvoid setLkmMobile(String lkmMobile) {
this.lkmMobile = lkmMobile;
}
public String getLkmEmail() {
return lkmEmail;
}
publicvoid setLkmEmail(String lkmEmail) {
this.lkmEmail = lkmEmail;
}
public String getLkmPosition() {
return lkmPosition;
}
publicvoid setLkmPosition(String lkmPosition) {
this.lkmPosition = lkmPosition;
}
public String getLkmMemo() {
return lkmMemo;
}
publicvoid setLkmMemo(String lkmMemo) {
this.lkmMemo = lkmMemo;
}
public Customer getCustomer() {
return customer;
}
publicvoid setCustomer(Customer customer) {
this.customer = customer;
}
@Override
public String toString() {
return"LinkMan{" + "lkmId=" + lkmId + ", lkmName='" + lkmName + '\'' + ", lkmGender='" + lkmGender + '\'' + ", lkmPhone='" + lkmPhone + '\'' + ", lkmMobile='" + lkmMobile + '\'' + ", lkmEmail='" + lkmEmail + '\'' + ", lkmPosition='" + lkmPosition + '\'' + ", lkmMemo='" + lkmMemo + '\'' + '}';
}
}
测试类
package xyz.ytfs.test;import org.hibernate.loader.plan.build.internal.returns.CollectionFetchableIndexAnyGraph;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 xyz.ytfs.dao.ICustomerDao;import xyz.ytfs.dao.ILinkMan;import xyz.ytfs.entity.Customer;import xyz.ytfs.entity.LinkMan;import javax.transaction.Transactional;import javax.validation.constraints.AssertFalse;import java.util.List;import java.util.Optional;/** * @Classname JpaOnetoManyTest
* @Description TODO(JPA多对一的测试类)
* @Date 2020/5/9 0:10
* @Created by ytfs
*/@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:applicationContext.xml")publicclass JpaOnetoManyTest {
@Autowired
private ICustomerDao customerDao;
@Autowired
private ILinkMan linkManDao;
@Test
@Transactional //配置事务@Rollback(false)//不自动回滚publicvoid testSave1() {
Customer customer =new Customer();
customer.setCustName("雨听风说");
LinkMan linkMan =new LinkMan();
linkMan.setLkmName("小邓");
/* * 配置了客户到联系人的关系
* 从客户的角度上:发送两条insert语句,发送一条更新语句更新数据库(更新外键)
* 由于我们配置了客户到联系人的关系:客户可以对外键进行维护
*/ customer.getLinkMans().add(linkMan);
this.customerDao.save(customer);
this.linkManDao.save(linkMan);
}
@Test
@Transactional //配置事务@Rollback(false)//不自动回滚publicvoid testSave2() {
//创建一个客户,创建一个联系人Customer customer =new Customer();
customer.setCustName("百度");
LinkMan linkMan =new LinkMan();
linkMan.setLkmName("小李");
/** * 配置联系人到客户的关系(多对一)
* 只发送了两条insert语句
* 由于配置了联系人到客户的映射关系(多对一)
*
*
*/ linkMan.setCustomer(customer);
this.customerDao.save(customer);
this.linkManDao.save(linkMan);
}
/** * 会有一条多余的update语句
* * 由于一的一方可以维护外键:会发送update语句
* * 解决此问题:只需要在一的一方放弃维护权即可
*/ @Test
@Transactional //配置事务@Rollback(false)//不自动回滚publicvoid testAdd2() {
//创建一个客户,创建一个联系人Customer customer =new Customer();
customer.setCustName("百度");
LinkMan linkMan =new LinkMan();
linkMan.setLkmName("小李");
linkMan.setCustomer(customer);//由于配置了多的一方到一的一方的关联关系(当保存的时候,就已经对外键赋值)customer.getLinkMans().add(linkMan);//由于配置了一的一方到多的一方的关联关系(发送一条update语句)this.customerDao.save(customer);
this.linkManDao.save(linkMan);
}
/** * 级联添加:保存一个客户的同时,保存客户的所有联系人
* 需要在操作主体(这里就是Customer)的实体类上,配置casacde属性
*/ @Test
@Transactional
@Rollback(false)
publicvoid testSaveCasacde() {
Customer customer =new Customer();
customer.setCustName("雨听风说1");
LinkMan linkMan =new LinkMan();
linkMan.setLkmName("小李1");
/* 表达关系
*/ customer.getLinkMans().add(linkMan);
linkMan.setCustomer(customer);
/* 级联操作得时候在保存客户得同时会自动保存客户对应得联系人,但是需要在一的一方配置级联操作
*/this.customerDao.save(customer);
}
@Test
@Transactional //配置事务@Rollback(false)//不自动回滚publicvoid testCascadeRemove() {
//1.查询1号客户Customer customer = customerDao.getOne(1l);
//2.删除1号客户 System.out.println(customer);
customerDao.delete(customer);
}
}
对象导航查询测试
package xyz.ytfs.test;import org.aspectj.weaver.ast.Var;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 xyz.ytfs.dao.ICustomerDao;import xyz.ytfs.dao.ILinkMan;import xyz.ytfs.entity.Customer;import xyz.ytfs.entity.LinkMan;import java.util.Optional;import java.util.Set;
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:applicationContext.xml")publicclass ObjectQueryTest {
@Autowired
private ICustomerDao customerDao;
@Autowired
private ILinkMan linkManDao;
//could not initialize proxy - no Session
//测试对象导航查询(查询一个对象的时候,通过此对象查询所有的关联对象) @Test
@Transactional // 解决在java代码中的no session问题publicvoid testQuery1() {
//查询id为1的客户Customer customer =this.customerDao.getOne(1L);
//对象导航查询,此客户下的所有联系人Set linkMans = customer.getLinkMans();
linkMans.forEach(System.out::println);
}
/** * 对象导航查询:
* 默认使用的是延迟加载的形式查询的
* 调用get方法并不会立即发送查询,而是在使用关联对象的时候才会差和讯
* 延迟加载!
* 修改配置,将延迟加载改为立即加载
* fetch,需要配置到多表映射关系的注解上
*
*/ @Test
@Transactional // 解决在java代码中的no session问题publicvoid testQuery2() {
//查询id为1的客户Customer customer =this.customerDao.getOne(1L);
//对象导航查询,此客户下的所有联系人Set linkMans = customer.getLinkMans();
linkMans.forEach(System.out::println);
}
/** * 从联系人对象导航查询他的所属客户
* * 默认 : 立即加载
* 延迟加载:
*
*/ @Test
@Transactional // 解决在java代码中的no session问题publicvoid testQuery3() {
//对象导航查询所属的客户LinkMan linkMan =this.linkManDao.getOne(1L);
Customer customer = linkMan.getCustomer();
System.out.println("customer = " + customer);
}
}