Dear all,
I am getting NullPointerException in the following code for the
transaction tx. Please reply me soon.
Code:
package com.wissen.enterprisebysush.
server;
import java.util.List;
import javax.jdo.JDOHelper;
import javax.jdo.PersistenceManager;
import javax.jdo.PersistenceManagerFactory;
import javax.jdo.Transaction;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.Persistence;
import javax.persistence.Query;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import com.wissen.enterprisebysush.client.GreetingService;
import com.wissen.enterprisebysush.server.domainobject.Department;
import com.wissen.enterprisebysush.server.domainobject.Employee;
/**
* The server side implementation of the RPC service.
*/
@SuppressWarnings("serial")
public class GreetingServiceImpl extends RemoteServiceServlet implements
GreetingService {
EntityManagerFactory emf =
Persistence.createEntityManagerFactory("transactions-optional");
public String greetServer(String input) {
String serverInfo = getServletContext().getServerInfo();
String userAgent = getThreadLocalRequest().getHeader("User-Agent");
return "Hello, " + input + "!I am running " + serverInfo +
".It looks like you are using:" + userAgent;
}
@SuppressWarnings("unchecked")
public void addDept(String dept_name, String dept_head) {
EntityManager em = null;
try {
em = emf.createEntityManager();
em.getTransaction().begin();
Department d = new Department();
d.setDept_name(dept_name);
d.setHead(dept_head);
Query q = em.createQuery("select from
com.wissen.enterprisebysush.server.domainobject.Department d");
List deptList = q.getResultList();
for (Department dept : deptList) {
System.out.println("Department name: " +
dept.getDept_name());
}
em.persist(d);
} finally {
em.getTransaction().commit();
em.close();
}
}
public void addEmp(String emp_name, String emp_sal, String did) {
EntityManager em = emf.createEntityManager();
try {
String s = did;
EntityTransaction transaction = em.getTransaction();
transaction.begin();
System.out.println("value of Department_name is::" + s);
System.out.println("Transaction is active and
is::"+transaction);
//Query q = em.createQuery("select dept_id from
com.wissen.enterprisebysush.server.domainobject.Department d where
d.dept_name = ?1");
//q.setParameter(1, s);
//System.out.println("Name of Department is::" + s);
//Department dept = (Department)
q.getSingleResult();
Query q = em.createQuery("select from
com.wissen.enterprisebysush.server.domainobject.Department d");
Department dept = (Department) q.getResultList().get(0);
System.out.println("Name of Department is::" +
dept.getDept_name());
//System.out.println("Query executed Successfully!!"
+ q.getSingleResult());
Employee e = new Employee();
e.setEmp_name("Ritesh Navandar");
e.setEmp_sal("5000");
e.setDepartment(dept);
em.persist(e);
System.out.println("Transaction: " + transaction);
transaction.commit();
em.close();
} catch (NullPointerException e) {
e.printStackTrace();
System.out.println("Exception::" + e.getCause());
} finally {
}
}
}
--
Regards,
Sujata...
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