JavaWeb应用开发实验报告-实验十 JPA-1

第第页实验十JPA-1一、实验目的1、掌握JPA的实体的编写；2、掌握JPA的EntityManager的使用。二、实验环境PC系列微机：CPU2G以上，内存2G以上，硬盘可以空间：5G以上。操作系统：Windows10。三、实验步骤1、编写实体类User。2、使用持久化上下文与EntityManager实现对User的增删改查。3、调试和运行程序。四、实验报告1、请写出User实体的关键代码。packageentity;importjava.sql.Date;importjavax.persistence.Entity;importjavax.persistence.Id;@EntitypublicclassUser{ @Id privateintid; privateStringname; privateStringpassword; privateintage; privateDatebirthday; publicvoidsetId(intid){ this.id=id; } publicintgetId(){ returnid; } publicStringgetName(){ returnname; } publicvoidsetName(Stringname){ =name; } publicStringgetPassword(){ returnpassword; } publicvoidsetPassword(Stringpassword){ this.password=password; } publicintgetAge(){ returnage; } publicvoidsetAge(intage){ this.age=age; } publicDategetBirthday(){ returnbirthday; } publicvoidsetBirthday(Datebirthday){ this.birthday=birthday; }}请写出使用持久化上下文与EntityManager实现对User的增删改查的代码。publicclassTest{ //数据库增加对象方法 publicvoidadd(Useruser){ StringpersistenceUnitName="javaWeb10"; EntityManagerFactoryemfactory=Persistence.createEntityManagerFactory(persistenceUnitName); EntityManagerem=emfactory.createEntityManager(); em.getTransaction().begin(); em.persist(user); em.getTransaction().commit(); em.close(); emfactory.close(); } //数据库删除对象方法 publicvoiddelete(intid){ StringpersistenceUnitName="javaWeb10"; EntityManagerFactoryemfactory=Persistence.createEntityManagerFactory(persistenceUnitName); EntityManagerem=emfactory.createEntityManager(); em.getTransaction().begin(); Useruser=em.find(User.class,id); if(user!=null){ em.remove(user); } em.getTransaction().commit(); em.close(); emfactory.close(); } //数据库更新对象方法 publicvoidupdate(Useruser){ StringpersistenceUnitName="javaWeb10"; EntityManagerFactoryemfactory=Persistence.createEntityManagerFactory(persistenceUnitName); EntityManagerem=emfactory.createEntityManager(); em.getTransaction().begin(); UsermanagedUser=em.merge(user); em.getTransaction().commit(); em.close(); emfactory.close(); } //数据库查找对象方法 publicUserget(intid){ EntityManagerem=JpaUtils.getEntityManager(); em.getTransaction().begin(); Useruser=em.find(User.class,id); em.getTransaction().commit(); em.close(); returnuser; } publicstaticvoidmain(String[]args){ Useruser=newUser(); user.setName("李四"); user.setAge(20); user.setPassword("123456789"); UserDaouserDao=newUserDao(); User