JPA相关课程 代码

完整测试项目可在这里下载：http://download.csdn.net/detail/liangrui1988/6542729

部分代码：

META-INF

persistence.xml

<?xml version="1.0" encoding="UTF-8"?><persistence xmlns="http://java.sun.com/xml/ns/persistence"   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"   version="1.0">   <persistence-unit name="rui" transaction-type="RESOURCE_LOCAL">   <!--  全局事务配置      <jta-data-source>java:/DefaultDS</jta-data-source> -->      <properties>        <!-- hibernate config org.hibernate.dialect.HSQLDialect        org.hibernate.dialect.MySQLDialect        -->         <property name="hibernate.dialect" value="org.hibernate.dialect.OracleDialect"/>         <property name="hibernate.hbm2ddl.auto" value="update"/>         <property name="show_sql" value="true"/>                   <!-- database config -->         <property name="hibernate.connection.driver_class" value="oracle.jdbc.driver.OracleDriver"/>         <property name="hibernate.connection.username" value="juxun"/>         <property name="hibernate.connection.password" value="rui"/>         <property name="hibernate.connection.url" value="jdbc:oracle:thin:@127.0.0.1:1521:ABC"/>                      <!--   <property name="hibernate.max_fetch_depth" value="3"/> -->             </properties>   </persistence-unit></persistence>

ManyToMany

package com.rui.ManyToMany;import java.util.HashSet;import java.util.Set;import javax.persistence.CascadeType;import javax.persistence.Entity;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.JoinColumn;import javax.persistence.JoinTable;import javax.persistence.ManyToMany;import org.hibernate.annotations.GenericGenerator;import org.hibernate.annotations.Parameter;@Entity@GenericGenerator(name = "stuId", strategy = "sequence",parameters=@Parameter(name="sequence",value="preson_id"))public class Student {private Integer id;private String name;private Set<Teacher> teacher=new HashSet<Teacher>();@Id@GeneratedValue(generator="stuId")public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}@ManyToMany(cascade={CascadeType.REFRESH})//@JoinTable(name="stu_tea")@JoinTable(name="stu_tea",inverseJoinColumns=@JoinColumn(name="tea_id"),joinColumns=@JoinColumn(name="stu_id"))public Set<Teacher> getTeacher() {return teacher;}public void setTeacher(Set<Teacher> teacher) {this.teacher = teacher;}//添加学生和老师的关系public void addTeacher(Teacher te){this.teacher.add(te);}//解除学生跟老师的关系public void removeTeacher(Teacher te){if(this.teacher.contains(te)){this.teacher.remove(te);}}}

package com.rui.ManyToMany;import java.util.HashSet;import java.util.Set;import javax.persistence.CascadeType;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.FetchType;import javax.persistence.GeneratedValue;import javax.persistence.Id;import javax.persistence.ManyToMany;import org.hibernate.annotations.GenericGenerator;import org.hibernate.annotations.Parameter;@Entity@GenericGenerator(name = "teaId", strategy = "sequence",parameters=@Parameter(name="sequence",value="preson_id"))public class Teacher {private Integer id;private  String name;private Set<Student> student=new HashSet<Student>();@Id@GeneratedValue(generator="teaId")public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}@Column(length=10,nullable=false)public String getName() {return name;}public void setName(String name) {this.name = name;}//被维护端 mappedBy  (Teacher)老师被学生维护 (Student)@ManyToMany(cascade={CascadeType.REFRESH},mappedBy="teacher")public Set<Student> getStudent() {return student;}public void setStudent(Set<Student> student) {this.student = student;}//为hash分区@Overridepublic int hashCode() {final int prime = 31;int result = 1;result = prime * result + ((id == null) ? 0 : id.hashCode());return result;}@Overridepublic boolean equals(Object obj) {if (this == obj)return true;if (obj == null)return false;if (getClass() != obj.getClass())return false;Teacher other = (Teacher) obj;if (id == null) {if (other.id != null)return false;} else if (!id.equals(other.id))return false;return true;}}

package com.rui.ManyToMany;import static org.junit.Assert.*;import java.util.HashSet;import java.util.Set;import javax.persistence.EntityManager;import javax.persistence.EntityManagerFactory;import javax.persistence.Persistence;import org.junit.Test;import com.rui.ManyToOne.Order;import com.rui.ManyToOne.OrderItem;public class ManyToManyTest {@Testpublic void test() {EntityManagerFactory emf=Persistence.createEntityManagerFactory("rui"); EntityManager em= emf.createEntityManager(); em.getTransaction().begin();Teacher te=new Teacher();te.setName("刘老师");Teacher te2=new Teacher();te.setName("李老师");em.persist(te);//给学生分两个老师Student stu=new Student();stu.setName("小明");//stu.getTeacher().add(te);//学生加老师//stu.getTeacher().add(te2);em.persist(stu);//保存学生em.getTransaction().commit();em.close();emf.close();System.out.println("ok....");}/** * 建立关系 */@Testpublic void addRe(){EntityManagerFactory emf=Persistence.createEntityManagerFactory("rui"); EntityManager em= emf.createEntityManager(); em.getTransaction().begin();Student st=em.find(Student.class,46);//获取一个学生//刷新对象 获得老师 并建立关系st.addTeacher(em.getReference(Teacher.class,47));em.getTransaction().commit();em.close();emf.close();System.out.println("ok....");}/** * 删除关系 */@Testpublic void removeRe(){EntityManagerFactory emf=Persistence.createEntityManagerFactory("rui"); EntityManager em= emf.createEntityManager(); em.getTransaction().begin();Student st=em.find(Student.class,46);//获取一个学生st.removeTeacher(em.getReference(Teacher.class,45));//刷新对象 并建立关系em.getTransaction().commit();em.close();emf.close();System.out.println("ok....");}/** * 删除老师 */@Testpublic void deleteTeacher(){EntityManagerFactory emf=Persistence.createEntityManagerFactory("rui"); EntityManager em= emf.createEntityManager(); em.getTransaction().begin();//先解除关系才能删除老师Student st=em.find(Student.class,46);//获取一个学生st.removeTeacher(em.getReference(Teacher.class,45));//删除老师em.remove(em.getReference(Teacher.class,45));em.getTransaction().commit();em.close();emf.close();System.out.println("ok....");}/** * 删除学生 */@Testpublic void deleteStudent(){EntityManagerFactory emf=Persistence.createEntityManagerFactory("rui"); EntityManager em= emf.createEntityManager(); em.getTransaction().begin();Student st=em.find(Student.class,46);//获取一个学生//删除 学生 关系维护端 有权利操作外健em.remove(st);em.getTransaction().commit();em.close();emf.close();System.out.println("ok....");}}

ManyToOne

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package com.rui.ManyToOne;import javax.persistence.CascadeType;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.Id;import javax.persistence.JoinColumn;import javax.persistence.ManyToOne;@Entitypublic class OrderItem {private Integer id;private String productName;//产品名称private Float sellPrice;//销售价格private Order order;//订单@Id//@Column(name="ids",length=8)public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getProductName() {return productName;}public void setProductName(String productName) {this.productName = productName;}public Float getSellPrice() {return sellPrice;}public void setSellPrice(Float sellPrice) {this.sellPrice = sellPrice;}//optional =true 可选 ，存放的值可以为null(外健)@ManyToOne(cascade={CascadeType.REFRESH,CascadeType.MERGE},optional=false)@JoinColumn(name="order_id") //关联字段  外健idpublic Order getOrder() {return order;}public void setOrder(Order order) {this.order = order;}}

package com.rui.ManyToOne;import java.util.HashSet;import java.util.Set;import javax.persistence.CascadeType;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.FetchType;import javax.persistence.Id;import javax.persistence.OneToMany;import javax.persistence.Table;@Entity@Table(name="orders")public class Order {private String orderId;private Float amount;private Set<OrderItem> item=new HashSet<OrderItem>();@Id@Column(name="order_id",length=8)public String getOrderId() {return orderId;}public void setOrderId(String orderId) {this.orderId = orderId;}@Column(nullable=false)public Float getAmount() {return amount;}public void setAmount(Float amount) {this.amount = amount;}/** * alter table OrderItem * add constraint pk_order foreign key order * reference order(orderId) * 一个订单对应多个订单项 * 多个订单项对应一个订单 * @return *///那个类出现了mappedBy 就是关系被维护端  //order 指定这个属性来维据关系 @OneToMany(cascade={CascadeType.REFRESH,CascadeType.PERSIST,CascadeType.MERGE,CascadeType.REMOVE} ,fetch=FetchType.LAZY,mappedBy="order")public Set<OrderItem> getItem() {return item;}public void setItem(Set<OrderItem> item) {this.item = item;}public void addOrderItem(OrderItem oi){oi.setOrder(this);//送来的订单项对象里加入 订单this.item.add(oi);//添加订单   里的订单项}}

package com.rui.ManyToOne;import static org.junit.Assert.*;import java.util.UUID;import javax.persistence.EntityManager;import javax.persistence.EntityManagerFactory;import javax.persistence.Persistence;import org.junit.Test;public class OneToManyTest {@Testpublic void test() {EntityManagerFactory emf=Persistence.createEntityManagerFactory("rui");  EntityManager em= emf.createEntityManager(); em.getTransaction().begin();Order order=new Order();order.setOrderId("888");//UUID.randomUUID().toString()order.setAmount(90F);OrderItem oi=new OrderItem();oi.setId(20);oi.setProductName("ipone");oi.setSellPrice(5888F);//oi.setOrder(order);OrderItem oi2=new OrderItem();oi2.setId(21);oi2.setProductName("ipone6");oi2.setSellPrice(6888F);//订单里加入订单项order.addOrderItem(oi);order.addOrderItem(oi2);//插入订单em.persist(order);em.getTransaction().commit();emf.close();System.out.println("ok....");}}

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复合主健

package com.rui.compositePK;import javax.persistence.EmbeddedId;import javax.persistence.Entity;@Entitypublic class AriLine {private AriLinePK id;//这里把复合主健看成一个整体 用一个类来描述它private String name;public AriLine(){}public AriLine(String stratCity,String endCity,String name){this.id=new AriLinePK(stratCity,endCity);        this.name=name;}@EmbeddedId //可嵌入的类 idpublic AriLinePK getId() {return id;}public void setId(AriLinePK id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}}