Eclipse jee下JPA的开发配置

1、配置JPA。点击window --> Preferences的“参数选择”对象框当中选择JPA；接着，点击Configure User Libraries，在用户类库当中将OpenJPA的核心包以及依赖的外部包文件加到OpenJPA Library当中。配置后的效果图如下所示：

2、配置数据库连接，点击window --> Preferences的“参数选择”对象框当中选择Connectivity--> Driver Definitions，在数据库的选择项当中选择Mysql，并添加Mysql JDBC Driver。最终的效果如下图所示：

3、创建新的JPA Project：点击File --> New --> Other，在弹出的创建向导当中选择JPA，如下图所示：

4、点击Next（下一步）。在窗口当中输入项目名称，比如JPATraining，其它默认

5、点击Next(下一步)

6、各项默认就可以了，点击下一步

7、一切都默认就可以，因为之前已经配置完了。最后点击Finish。最后，可以在Project Explorer当中看到src/META-INF/下面多了两个文件，一个叫persistence.xml，另一个叫orm.xml

8、程序的编写：1、数据库脚本程序代码 Create TABLE ECA_USER(ID I鲍伊酷雪NT NOT NULL AUTO_INCREMENT,NAME VAR潮贾篡绐CHAR(20)NOT NULL,LOGINID VARCHAR(20)NOT NULL,PASSWORD VARCHAR(32)NOT NULL,AGE INT NOT NULL,PRIMARY KEY(ID));2，Entity程序代码packagecom.suneca.entity;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.Id;import javax.persistence.Table;import javax.persistence.GeneratedValue;importstaticjavax.persistence.GenerationType.IDENTITY;/**** @author ChenYuzhe* @version 1.0* Create-Time：2008-7-16 下午06:55:22*/@Entity@Table(name="ECA_USER")publicclassUser{@Id@GeneratedValue(strategy=IDENTITY)privateintid;@Column(name="NAME")privateString name;@Column(name="LOGINID")privateString loginId;@Column(name="PASSWORD")privateString password;@Column(name="AGE")privateintage;publicintgetId(){returnid;}publicString getName(){returnname;}publicString getLoginId(){returnloginId;}publicString getPassword(){returnpassword;}publicintgetAge(){returnage;}publicvoidsetId(intid){this.id=id;}publicvoidsetName(String name){this.name=name;}publicvoidsetLoginId(String loginId){this.loginId=loginId;}publicvoidsetPassword(String password){this.password=password;}publicvoidsetAge(intage){this.age=age;}}3，测试类的编写程序代码 package com.suneca.test;import javax.persistence.EntityManager;import javax.persistence.EntityManagerFactory;import javax.persistence.Persistence;import javax.persistence.EntityTransaction;import com.suneca.entity.User;/**** @author ChenYuzhe* @version 1.0* Create-Time：2008-7-16 下午06:55:08*/publicclass UserTest{publicstaticvoidmain(String[]args){// get Entity ManagerEntityManagerFactory factory=Persistence.createEntityManagerFactory("MyJPA");long startTime=System.currentTimeMillis();EntityManager em=factory.createEntityManager();// get Transaction and Begin TransactionEntityTransaction transaction=em.getTransaction();transaction.begin();User user=newUser();user.setName("陈毓哲");user.setLoginId("zizz");user.setPassword("admin");user.setAge(28);em.persist(user);// Committransaction.commit();long endTime=System.currentTimeMillis();System.out.println(endTime-startTime);em.close();}}4，persistence.xml的修改程序代码<?xml version="1.0"encoding="UTF-8"?><persistence version="1.0"xmlns="http://java.sun.com/xml/ns/persistence"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://java.sun.com/xml/ns/persistencehttp://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"><persistence-unit name="MyJPA"transaction-type="RESOURCE_LOCAL"><!-- 定义jpa的Provider --><provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider><!-- 定义持久化实体 --><class>com.suneca.entity.User</class><!-- 定义jpa的数据库参数 --><properties><property name="openjpa.ConnectionURL"value="jdbc:mysql://localhost:3306/suneca"/><property name="openjpa.ConnectionDriverName"value="com.mysql.jdbc.Driver"/><property name="openjpa.ConnectionUserName"value="root"/><property name="openjpa.ConnectionPassword"value="admin"/></properties></persistence-unit></persistence>