eclipselink使用

最新推荐文章于 2024-01-25 20:45:30 发布

zhou___

最新推荐文章于 2024-01-25 20:45:30 发布

阅读量2.3k

点赞数

CC 4.0 BY-SA版权

分类专栏： jpa 文章标签： string myeclipse installer class jpa 数据库

本文链接：https://blog.youkuaiyun.com/zhou___/article/details/7225331

jpa 专栏收录该内容

2 篇文章

订阅专栏

本文介绍了如何在MyEclipse环境中利用EclipseLink完成简单的持久化操作，包括实体类创建、数据库连接配置、实体类测试等步骤。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

1.在http://www.eclipse.org/eclipselink/downloads/ 下载EclipseLink Installer Zip

2.解压。文件夹jlib下的eclipselink.jar，和文件夹jlib\jpa的javax.persistence_*.jar需要用到。

3.在myeclipse中创建一下工程，将上面jar包导入WEB-INF/lib文件夹中。同时导入mysql-connector-java-5.1.7-bin.jar（该包是连接mysql数据库的）

4.创建实体类Todo.java

package jpa.simple.model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;

@Entity
public class Todo {
	@Id
	@GeneratedValue
	private int id;
	private String summary;
	private String description;

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getSummary() {
		return summary;
	}

	public void setSummary(String summary) {
		this.summary = summary;
	}

	public String getDescription() {
		return description;
	}

	public void setDescription(String description) {
		this.description = description;
	}

	@Override
	public String toString() {
		return "Todo [summary=" + summary + ", description=" + description
				+ "]";
	}

}

创建Main.java类，用来简单的测试上面的实体类：

package jpa.simple.main;

import java.util.List;

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

import jpa.simple.model.Todo;

public class Main {
	private static final String PERSISTENCE_UNIT_NAME = "todos";
	private static EntityManagerFactory factory;

	public static void main(String[] args) {
		factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
		EntityManager em = factory.createEntityManager();
		// Read the existing entries and write to console
		Query q = em.createQuery("select t from Todo t");
		List<Todo> todoList = q.getResultList();
		for (Todo todo : todoList) {
			System.out.println(todo);
		}
		System.out.println("Size: " + todoList.size());

		// Create new todo
		em.getTransaction().begin();
		Todo todo = new Todo();
		todo.setSummary("This is a test");
		todo.setDescription("This is a test");
		em.persist(todo);
		em.getTransaction().commit();

		em.close();
	}
}

运行Main.java

成功！！！

参考链接：http://www.vogella.de/articles/JavaPersistenceAPI/article.html