JPA read data from database example

In this section, you will learn how to retrieve data from database using JPA. Create a "JPARead.java" file and follows the following steps to reading data from database.

Ads

JPA read data from database example

     

In this section, you will learn how to retrieve data from database using JPA. Create a "JPARead.java" file and follows the following steps to reading data from database.

Create "JPARead" class file.



Put the following text in "JPARead.java" file.



JPARead.java
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/

package roseindia;

import java.util.Iterator;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.Persistence;
import javax.persistence.Query;

/**
*
* @author Administrator
*/
public class JPARead {
public static void main(String arg[]){
EntityManagerFactory emf=Persistence.createEntityManagerFactory("netjpa");
EntityManager em=emf.createEntityManager();
try{
EntityTransaction entr=em.getTransaction();
entr.begin();
Query query=em.createNamedQuery("readAllRecords");
List stList=query.getResultList();
Iterator stIterator=stList.iterator();
while(stIterator.hasNext()){
Student stu=(Student)stIterator.next();
System.out.print("Name:"+stu.getSname());
System.out.print(" Roll:"+stu.getSroll());
System.out.print(" Course:"+stu.getScourse());
System.out.println();
}
entr.commit();
}
catch(Exception e){
System.out.println(e.getMessage());
}
finally{
em.close();
}
}
}
Run it and get the following output:

Advertisements

Share on Google+Share on Google+

JPA read data from database example

Posted on: April 3, 2006 If you enjoyed this post then why not add us on Google+? Add us to your Circles

Advertisements

 

Discuss: JPA read data from database example  

Post your Comment


Your Name (*) :
Your Email :
Subject (*):
Your Comment (*):
  Reload Image
 
 
Comments:0

Ads

 

Ads