eclipselink使用

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;@Entitypublic class Todo {@Id@GeneratedValueprivate 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;}@Overridepublic 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 consoleQuery 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 todoem.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