20130118
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package com.hanqi.dao; import static org.junit.Assert.*; import java.util.*; import javax.persistence.*; import org.junit.*; public class TestJPA { EntityManagerFactory entityManagerFactory = null; EntityManager entityManager = null; EntityTransaction transaction = null; @Before public void hider(){ //1. 创建 EntitymanagerFactory String persistenceUnitName = "TestJPA"; entityManagerFactory = Persistence.createEntityManagerFactory(persistenceUnitName); //2. 创建 EntityManager. 类似于 Hibernate 的 SessionFactory entityManager = entityManagerFactory.createEntityManager(); //3. 开启事务 transaction = entityManager.getTransaction(); transaction.begin(); } @Test public void testJPQL(){ String jpql = "from JPANews n where n.id = ?"; Query q = entityManager.createQuery(jpql); // Query q = entityManager.createNamedQuery("cx"); q.setParameter(1,6); //占位符序号从1开始 List<JPANews> l = q.getResultList(); System.out.println("size = " + l.size()); } @Test public void test() { //数据操作 //保存 JPANews jn = new JPANews(); jn.setTitle("标题"); jn.setContent("内容"); jn.setAuthor("作者"); jn.setCreatedate(new Date()); // entityManager.persist(jn);//保存 JPANews jn2 = entityManager.merge(jn);//saveOrUpdate System.out.println("jn = " + jn); System.out.println("jn2 = " + jn2); //查找 //立即加载 JPANews jpan = entityManager.find(JPANews.class,1); jpan.setTitle("新的标题"); entityManager.flush();//提交语句给数据库,事务还未提交 // System.out.println(jpan); /* //延迟加载 JPANews jpan2 = entityManager.getReference(JPANews.class,3); System.out.println("id = " + jpan2.getId()); System.out.println("title = " + jpan2.getTitle()); //删除 entityManager.remove(jpan2);//删除 */ } @After public void test1() { //5. 提交事务 transaction.commit(); //6. 关闭 EntityManager entityManager.close(); //7. 关闭 EntityManagerFactory entityManagerFactory.close(); } }
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package com.hanqi.dao; import java.util.Date; import javax.persistence.*; //@NamedQuery(name="cx",query="SELECT n.id from JPANews n where n.id = ?") @Table(name="JPA_News") //类与表之间的映射关系 @Entity //实体类 public class JPANews { private Integer id; private String title; private String content; private Date createdate; private String author; public String getAuthor() { return author; } public void setAuthor(String author) { this.author = author; } @GeneratedValue(strategy=GenerationType.AUTO) //生成主键的策略 @Id //指定主键 public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getContent() { return content; } public void setContent(String content) { this.content = content; } @Column(name="CREATE_DATE") @Basic public Date getCreatedate() { return createdate; } public void setCreatedate(Date createdate) { this.createdate = createdate; } @Override @Transient public String toString() { return "JPANews [id=" + id + ", title=" + title + ", content=" + content + ", createdate=" + createdate + ", author=" + author + "]"; } }