Simple JPA Program using Eclipselink 1.1 in Eclipse

[Pawan Choure]

users.java

    
package test;

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.NamedQuery;

@Entity
@NamedQuery(name="GetUser", query="Select u from users where u.email='abhi'" )
public class users {
	 @Id
	  protected String email;
	  private String password;
	  private Double cash;
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public Double getCash() {
		return cash;
	}
	public void setCash(Double cash) {
		this.cash = cash;
	}
	  
}

usertester.java

package test;

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

public class usertester {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// Creates an instance of users
		users U=new users();
		U.setEmail("[e-mail]");
		U.setPassword("Password");
		U.setCash(100.0);
		// Gets an entity manager and a transaction
		EntityManagerFactory emf = Persistence.createEntityManagerFactory("JPATester");
		EntityManager em = emf.createEntityManager();
		
		// Persists the book to the database
		EntityTransaction tx = em.getTransaction();
		tx.begin();
		em.persist(U);
		tx.commit();
		em.close();
		emf.close();

		
	

	}

}

persistence.xml

<?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/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
	<persistence-unit name="JPATester">
		<class>test.users</class>
<properties>
<property name="eclipelink.jdbc.url" value="jdbc:mysql://localhost:3306/testjdbc"/> 
<property name="eclipelink.jdbc.user" value="root"/> 
<property name="eclipelink.jdbc.driver" value="com.mysql.jdbc.Driver"/> 
<property name="eclipelink.jdbc.password" value="root"/> 
<property name="eclipelink.ddl-generation" value="create-tables"/> 
<property name="eclipelink.jdbc.connections.min" value="1"/> 
<property name="eclipelink.jdbc.connections.max" value="2"/> 
<property name="eclipelink.logging.level" value="FINEST"/> 
</properties>
	</persistence-unit>
</persistence>

orm.xml

<?xml version="1.0" encoding="UTF-8"?>
<entity-mappings version="1.0" xmlns="http://java.sun.com/xml/ns/persistence/orm" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence/orm http://java.sun.com/xml/ns/persistence/orm_1_0.xsd">
</entity-mappings>

I have created a JPAProject in Eclipse and above are code files i have used but when i am trying to run i am getting following error.

[EL Info]: 2010-10-22 15:08:30.668--ServerSession(25772535)--EclipseLink, version: Eclipse Persistence Services - 1.1.3.v20091002-r5404
[EL Severe]: 2010-10-22 15:08:30.684--ServerSession(25772535)--Local Exception Stack: 
Exception [EclipseLink-4021] (Eclipse Persistence Services - 1.1.3.v20091002-r5404): org.eclipse.persistence.exceptions.DatabaseException
Exception Description: Unable to acquire a connection from driver [null], user [null] and URL [null].  Verify that you have set the expected driver class and URL.  Check your login, persistence.xml or sessions.xml resource.  The jdbc.driver property should be set to a class that is compatible with your database platform
	at org.eclipse.persistence.exceptions.DatabaseException.unableToAcquireConnectionFromDriverException(DatabaseException.java:375)
	at org.eclipse.persistence.sessions.DefaultConnector.connect(DefaultConnector.java:90)
	at org.eclipse.persistence.sessions.DatasourceLogin.connectToDatasource(DatasourceLogin.java:162)
	at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.loginAndDetectDatasource(DatabaseSessionImpl.java:583)
	at org.eclipse.persistence.internal.jpa.EntityManagerFactoryProvider.login(EntityManagerFactoryProvider.java:227)
	at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:255)
	at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.getServerSession(EntityManagerFactoryImpl.java:112)
	at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManagerImpl(EntityManagerFactoryImpl.java:164)
	at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:151)
	at test.usertester.main(usertester.java:21)

Exception in thread "main" javax.persistence.PersistenceException: Exception [EclipseLink-4021] (Eclipse Persistence Services - 1.1.3.v20091002-r5404): org.eclipse.persistence.exceptions.DatabaseException
Exception Description: Unable to acquire a connection from driver [null], user [null] and URL [null].  Verify that you have set the expected driver class and URL.  Check your login, persistence.xml or sessions.xml resource.  The jdbc.driver property should be set to a class that is compatible with your database platform
	at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:272)
	at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.getServerSession(EntityManagerFactoryImpl.java:112)
	at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManagerImpl(EntityManagerFactoryImpl.java:164)
	at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:151)
	at test.usertester.main(usertester.java:21)
Caused by: Exception [EclipseLink-4021] (Eclipse Persistence Services - 1.1.3.v20091002-r5404): org.eclipse.persistence.exceptions.DatabaseException
Exception Description: Unable to acquire a connection from driver [null], user [null] and URL [null].  Verify that you have set the expected driver class and URL.  Check your login, persistence.xml or sessions.xml resource.  The jdbc.driver property should be set to a class that is compatible with your database platform
	at org.eclipse.persistence.exceptions.DatabaseException.unableToAcquireConnectionFromDriverException(DatabaseException.java:375)
	at org.eclipse.persistence.sessions.DefaultConnector.connect(DefaultConnector.java:90)
	at org.eclipse.persistence.sessions.DatasourceLogin.connectToDatasource(DatasourceLogin.java:162)
	at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.loginAndDetectDatasource(DatabaseSessionImpl.java:583)
	at org.eclipse.persistence.internal.jpa.EntityManagerFactoryProvider.login(EntityManagerFactoryProvider.java:227)
	at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:255)
	... 4 more

so please help me out to solve the above issue

[James Sutherland]

Odd, the error says you did not set your jdbc properties, but you do seem to be setting them in your persistence.xml.

Ensure that you are using the persistence.xml that you think you are (in META-INF), and you don't have any old ones on your classpath. Maybe try to run it outside of Eclipse so you know exactly what is on your classpath. Also ensure you have your JDBC driver on the classpath, and check your log for other errors.

[Pawan Choure]

Finally I got it working.I create a a new JPA Project from Scratch and was still facing the same issue but finally got it working my changing the name of Database to MySQL.

user class

   
package test;

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.NamedQuery;


//@NamedQuery(name="GetUser", query="Select u from users" )
@Entity
public class users {
	 @Id
	  protected String email;
	  private String password;
	  private Double cash;
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public Double getCash() {
		return cash;
	}
	public void setCash(Double cash) {
		this.cash = cash;
	}
	@Override
	public String toString() {
		return "users [cash=" + cash + ", email=" + email + ", password="
				+ password + "]";
	}
	  
}
 

usertester class

  
 package test;


import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.Persistence;
import javax.persistence.Query;
import javax.swing.JOptionPane;

public class usertester {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		
		
		// Gets an entity manager and a transaction
		EntityManagerFactory emf = Persistence.createEntityManagerFactory("JPAProgram");
		EntityManager em = emf.createEntityManager();
		
		//Query for Select all user from table users
		Query q=em.createQuery("select t from users t");
		List<users> userlist=q.getResultList();
		for(users u:userlist)
		{
			System.out.println(u);
		}
		
		//To Get the Number of Rows in the users table
		System.out.println("Size :"+userlist.size());
		
		// Creates an instance of users  for Inserting values into table users
		//Method 1
		users U=new users();
		U.setEmail(JOptionPane.showInputDialog("User Email:"));
		U.setPassword(JOptionPane.showInputDialog("Password :"));
	    String cash=JOptionPane.showInputDialog("Cash :");
		double c=Double.parseDouble(cash);
		U.setCash(c);
		EntityTransaction tx = em.getTransaction();
		tx.begin();
		em.persist(U);
		tx.commit();
		
		//Method 2
		em.getTransaction().begin();
		users um=new users();
		um.setEmail(JOptionPane.showInputDialog("User Email:"));
		um.setPassword(JOptionPane.showInputDialog("Password :"));
	    String cashum=JOptionPane.showInputDialog("Cash :");
		double cu=Double.parseDouble(cashum);
		um.setCash(cu);
		em.persist(um);
		em.getTransaction().commit();
		
		em.close();
		emf.close();

		
	

	}

}
 

orm.xml

<?xml version="1.0" encoding="UTF-8"?>
<entity-mappings version="1.0" xmlns="http://java.sun.com/xml/ns/persistence/orm" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence/orm http://java.sun.com/xml/ns/persistence/orm_1_0.xsd">
</entity-mappings>

persistence.xml

<?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/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
	<persistence-unit name="JPAProgram" transaction-type="RESOURCE_LOCAL">
	<provider>
         org.eclipse.persistence.jpa.PersistenceProvider
     </provider>
    
     <class>test.users</class>
     <properties>
          <property name="eclipselink.logging.level" value="FINE"/>
			<property name="eclipselink.logging.thread" value="false"/>
			<property name="eclipselink.logging.session" value="false"/>
			<property name="eclipselink.logging.timestamp" value="false"/>
			<property name="eclipselink.logging.exceptions" value="false"/>
			<property name="eclipselink.jdbc.url" value="jdbc:mysql://localhost:3306/testjdbc"/>
			<property name="eclipselink.jdbc.user" value="root"/>
			<property name="eclipselink.jdbc.password" value="root"/>
			<property name="eclipselink.jdbc.driver" value="com.mysql.jdbc.Driver"/>
			<property name="eclipselink.jdbc.read-connections.min" value="1"/>
			<property name="eclipselink.jdbc.write-connections.min" value="1"/>
			<property name="eclipselink.target-database" value="MySQL"/>
     </properties>
     
	
	</persistence-unit>
</persistence>