Can you post a stack trace? It's not helpful if we don't know what line of code is causing the exception.
On Mon, Feb 15, 2010 at 11:53 PM, sujata pagar <suja.paga...@gmail.com>wrote: > 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 + "!<br><br>I am running " + serverInfo + > ".<br><br>It looks like you are using:<br>" + 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<Department> 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... > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine for Java" group. > To post to this group, send email to > google-appengine-j...@googlegroups.com. > To unsubscribe from this group, send email to > google-appengine-java+unsubscr...@googlegroups.com<google-appengine-java%2bunsubscr...@googlegroups.com> > . > For more options, visit this group at > http://groups.google.com/group/google-appengine-java?hl=en. > -- Ikai Lan Developer Programs Engineer, Google App Engine http://googleappengine.blogspot.com | http://twitter.com/app_engine -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.