JPA（二）之CRUD操作

最新推荐文章于 2025-09-07 20:32:33 发布

转载最新推荐文章于 2025-09-07 20:32:33 发布 · 109 阅读

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原文链接：https://my.oschina.net/beanGo/blog/168230

文章标签：

#java #操作系统

本文详细介绍了一个使用JUnit进行数据库操作测试的Java案例，包括保存、查找、更新和删除等操作，并探讨了不同测试方法的实现及可能遇到的问题。

为什么80%的码农都做不了架构师？>>>

修改PerTest.java

具体代码如下：

package junit.test;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;

import org.junit.Test;

import com.sonoi.bean.Person;

public class PerTest {

	@Test
	public void save() {
		EntityManagerFactory factory = Persistence
				.createEntityManagerFactory("unitname");
		EntityManager manager = factory.createEntityManager();
		manager.getTransaction().begin();
		//不能输入汉字！针对my操作系统
		manager.persist(new Person("nansheng"));
		manager.getTransaction().commit();
		manager.close();
		factory.close();
	}
	
	@Test
	public void find1() {
		EntityManagerFactory factory = Persistence.createEntityManagerFactory("unitname");
		EntityManager manager = factory.createEntityManager();
		Person person = manager.find(Person.class, 2);
		System.out.println(person.getName());
		manager.close();
		factory.close();
	}
	
	@Test
	public void find2() {
		EntityManagerFactory factory = Persistence.createEntityManagerFactory("unitname");
		EntityManager manager = factory.createEntityManager();
		Person person = manager.getReference(Person.class, 1);
		System.out.println(person.getName());
		manager.close();
		factory.close();
	}
	
	@Test
	public void update1() {
		EntityManagerFactory factory = Persistence.createEntityManagerFactory("unitname");
		EntityManager manager = factory.createEntityManager();
		manager.getTransaction().begin();
		Person person = manager.getReference(Person.class, 1);
		person.setName("bbbbbbb");
		manager.getTransaction().commit();
		manager.close();
		factory.close();
	}
	
	//此更新方法有问题
	@Test
	public void update2() {
		EntityManagerFactory factory = Persistence.createEntityManagerFactory("unitname");
		EntityManager manager = factory.createEntityManager();
		manager.getTransaction().begin();
		Person person = manager.getReference(Person.class, 1);
		//增加此句代码会出错
		manager.clear();
//		manager.merge(person);
		person.setName("hhhhhhh");
		manager.getTransaction().commit();
		manager.close();
		factory.close();
	}
	
	@Test
	public void delete() {
		EntityManagerFactory factory = Persistence.createEntityManagerFactory("unitname");
		EntityManager manager = factory.createEntityManager();
		manager.getTransaction().begin();
		Person person = manager.getReference(Person.class, 2);
		manager.remove(person);
		manager.getTransaction().commit();
		manager.close();
		factory.close();
	}
	
}

转载于:https://my.oschina.net/beanGo/blog/168230