Myeclipse6.0实现JPA

1.首先先创建一个JAVA项目，之后对其添入JPA（项目-->右键-->MyEclipse->Add JPA 功能） ；

2.一般JPA对Toplink的支持比对hibernate的支持好点，所以我们直接默认就好，-->next；

3.选择JPA配置的数据源，（Driver 、catalog/Schema..） -->Finish ;

4.选中其中的一个表，右键-->创建JPA 反向工程 ；（我创建了一个表MyUser里面有字段：id pk,name varchar(20),password varchar(20) 。）

5.先设置放置的路径，我放在一个jpaDaoTest包中，产生一个实体Bean并更改persistence.xml产生一个实体。persistence.xml：


<?xml version="1.0" encoding="UTF-8"?>


<persistence 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/persistence

http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" version="1.0">




<persistence-unit name="jpaTestPU"


transaction-type="RESOURCE_LOCAL">


<provider>


oracle.toplink.essentials.PersistenceProvider


</provider>


<class>jpaDao.MyUser</class>


<class>jpaDaoTest.EisArea</class>


<properties>


<property name="toplink.jdbc.driver"


value="com.microsoft.jdbc.sqlserver.SQLServerDriver" />


<property name="toplink.jdbc.url"


value="jdbc:microsoft:sqlserver://210.51.168.147:1433;DatabaseName=www_souvi_com" />


<property name="toplink.jdbc.user" value="web1621510" />


<property name="toplink.jdbc.password" value="fhq2020" />


</properties>


</persistence-unit>




</persistence>



之后在勾选上 Java Data Access Generation创建接口和其实现方法。类型为Basic DAO默认即可。

6.Finish ;

MyUser.java


package jpaDao;




import javax.persistence.Column;


import javax.persistence.Entity;


import javax.persistence.Id;


import javax.persistence.Table;


import javax.persistence.GenerationType;


import javax.persistence.GeneratedValue;






/** *//**


* MyUser generated by MyEclipse Persistence Tools


*/


@Entity




@Table(catalog = "web1621510",schema = "www_souvi_com",name = "MyUser",uniqueConstraints = ...{})




public class MyUser implements java.io.Serializable ...{




// Fields




private Integer id;


private String name;


private String password;




// Constructors






/** *//** default constructor */




public MyUser() ...{


}






/** *//** minimal constructor */




public MyUser(Integer id) ...{


this.id = id;


}






/** *//** full constructor */




public MyUser(Integer id, String name, String password) ...{


this.id = id;


this.name = name;


this.password = password;


}




// Property accessors


@Id


@Column(name = "id", unique = true, nullable = false, insertable = true, updatable = true)


@GeneratedValue(strategy=GenerationType.IDENTITY)




public Integer getId() ...{


return this.id;


}






public void setId(Integer id) ...{


this.id = id;


}




@Column(name = "name", unique = false, nullable = true, insertable = true, updatable = true, length = 20)




public String getName() ...{


return this.name;


}






public void setName(String name) ...{


this.name = name;


}




@Column(name = "password", unique = false, nullable = true, insertable = true, updatable = true, length = 20)




public String getPassword() ...{


return this.password;


}






public void setPassword(String password) ...{


this.password = password;


}




}

IMyUserDAO.java


package jpaDao;




import java.util.List;






/** *//**


* Interface for MyUserDAO.


*


* @author MyEclipse Persistence Tools


*/






public interface IMyUserDAO ...{


public void save(MyUser transientInstance);




public void delete(MyUser persistentInstance);




public MyUser update(MyUser detachedInstance);




public MyUser findById(Integer id);




public List<MyUser> findByProperty(String propertyName, Object value);




public List<MyUser> findByName(Object name);




public List<MyUser> findByPassword(Object password);




public List<MyUser> findAll();


}

MyUserDAO.java


package jpaDao;




import java.util.List;


import java.util.logging.Level;


import javax.persistence.EntityManager;






/** *//**


* Data access object (DAO) for domain model class MyUser.


*


* @see jpaDao.MyUser


* @author MyEclipse Persistence Tools


*/






public class MyUserDAO implements IMyUserDAO ...{


// property constants


public static final String NAME = "name";


public static final String PASSWORD = "password";






private EntityManager getEntityManager() ...{


return EntityManagerHelper.getEntityManager();


}






public void save(MyUser transientInstance) ...{


EntityManagerHelper.log("saving MyUser instance", Level.INFO, null);




try ...{


getEntityManager().persist(transientInstance);


EntityManagerHelper.log("save successful", Level.INFO, null);




} catch (RuntimeException re) ...{


EntityManagerHelper.log("save failed", Level.SEVERE, re);


throw re;


}


}






public void delete(MyUser persistentInstance) ...{


EntityManagerHelper.log("deleting MyUser instance", Level.INFO, null);




try ...{


getEntityManager().remove(persistentInstance);


EntityManagerHelper.log("delete successful", Level.INFO, null);




} catch (RuntimeException re) ...{


EntityManagerHelper.log("delete failed", Level.SEVERE, re);


throw re;


}


}






public MyUser update(MyUser detachedInstance) ...{


EntityManagerHelper.log("updating MyUser instance", Level.INFO, null);




try ...{


MyUser result = getEntityManager().merge(detachedInstance);


EntityManagerHelper.log("update successful", Level.INFO, null);


return result;




} catch (RuntimeException re) ...{


EntityManagerHelper.log("update failed", Level.SEVERE, re);


throw re;


}


}






public MyUser findById(Integer id) ...{


EntityManagerHelper.log("finding MyUser instance with id: " + id,


Level.INFO, null);




try ...{


MyUser instance = getEntityManager().find(MyUser.class, id);


return instance;




} catch (RuntimeException re) ...{


EntityManagerHelper.log("find failed", Level.SEVERE, re);


throw re;


}


}




@SuppressWarnings("unchecked")




public List<MyUser> findByProperty(String propertyName, Object value) ...{


EntityManagerHelper.log("finding MyUser instance with property: "


+ propertyName + ", value: " + value, Level.INFO, null);




try ...{


String queryString = "select model from MyUser model where model."


+ propertyName + "= :propertyValue";


return getEntityManager().createQuery(queryString).setParameter(


"propertyValue", value).getResultList();




} catch (RuntimeException re) ...{


EntityManagerHelper.log("find by property name failed",


Level.SEVERE, re);


;


throw re;


}


}






public List<MyUser> findByName(Object name) ...{


return findByProperty(NAME, name);


}






public List<MyUser> findByPassword(Object password) ...{


return findByProperty(PASSWORD, password);


}




@SuppressWarnings("unchecked")




public List<MyUser> findAll() ...{


EntityManagerHelper.log("finding all MyUser instances", Level.INFO,


null);




try ...{


String queryString = "select model from MyUser model";


return getEntityManager().createQuery(queryString).getResultList();




} catch (RuntimeException re) ...{


EntityManagerHelper.log("find all failed", Level.SEVERE, re);


;


throw re;


}


}




}

现在我们写一个测试类吧，


import jpaDao.* ;


import java.util.*;




public class Test ...{






/** *//**


* @param args


*/




public static void main(String[] args) ...{


// 开始事务


EntityManagerHelper.beginTransaction();


// 创建DAO


MyUserDAO dao = new MyUserDAO();


// 创建对象


MyUser user = new MyUser() ;


user.setName("chenhao") ;


user.setPassword("password");


//保存对象


dao.save(user) ;


//事务提交


EntityManagerHelper.commit() ;


System.out.println("++++++++++++++++++++++++");


// 得到所有的数据并遍利


List<MyUser> result = dao.findAll() ;




for(MyUser o : result)...{


System.out.println("id = " + o.getId()) ;


System.out.println("name = " + o.getName()) ;


System.out.println("password = " + o.getPassword()) ;


}


}




}



console:


[TopLink Info]: 2008.04.01 12:26:29.484--ServerSession(26680060)--TopLink, version: Oracle TopLink Essentials - 2.0 (Build b40-rc (03/21/2007))


[TopLink Info]: 2008.04.01 12:27:08.437--ServerSession(26680060)--file:/D:/workspace/jpaTest/bin/-jpaTestPU login successful


2008-4-1 0:27:08 jpaDao.EntityManagerHelper log


信息: saving MyUser instance


2008-4-1 0:27:08 jpaDao.EntityManagerHelper log


信息: save successful


++++++++++++++++++++++++


2008-4-1 0:27:08 jpaDao.EntityManagerHelper log


信息: finding all MyUser instances


id = 1


name = chenhao

快试试吧！~