Good day to all; I'm developing a program using JSF2 and JPA2 (OpenJPA). Im also using IBM Rapid App Dev't v8 with WebSphere App Server v8 test server. I have two simple entities, Employee and Department. Each Department has many Employees and each Employee belongs to a Department (using deptno and workdept). My problem occurs when i tried to add a new employee and selecting a department from a combo box (using selectOneMenu - populated from Department table): when i run the program, the following error messages appeared: An Error Occurred: java.lang.NullPointerException Caused by: java.lang.NullPointerException - java.lang.NullPointerException I also tried to make another program using Deptno and Workdept as String instead of integer, still doesn't work. Pls help. Im also a newbie. Tnx and God bless. Below are my codes, configurations and setup. Just tell me if there are some codes that I forgot to include. Im also using Derby v10.5 as my database: CREATE SCHEMA RTS; CREATE TABLE RTS.DEPARTMENT (DEPTNO INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH 1, INCREMENT BY 1), DEPTNAME VARCHAR(30)); ALTER TABLE RTS.DEPARTMENT ADD CONSTRAINT PK_DEPARTMNET PRIMARY KEY (DEPTNO); CREATE TABLE RTS.EMPLOYEE (EMPNO INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH 1, INCREMENT BY 1), NAME VARCHAR(50), WORKDEPT INTEGER); ALTER TABLE RTS.EMPLOYEE ADD CONSTRAINT PK_EMPLOYEE PRIMARY KEY (EMPNO); Employee and Department Entities package rts.entities; import java.io.Serializable; import javax.persistence.*; @Entity public class Employee implements Serializable { private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int empno; private String name; //bi-directional many-to-one association to Department @ManyToOne @JoinColumn(name="WORKDEPT") private Department department; ....... getter and setter methods package rts.entities; import java.io.Serializable; import javax.persistence.*; import java.util.List; @Entity public class Department implements Serializable { private static final long serialVersionUID = 1L; @Id @GeneratedValue(strategy=GenerationType.IDENTITY) private int deptno; private String deptname; //bi-directional many-to-one association to Employee @OneToMany(mappedBy="department") private List<Employee> employees; ....... getter and setter methods JSF 2 snipet using combo box (populated from Department table) <tr> <td align="left">Department</td> <td style="width: 5px">&#160;</td> <td><h:selectOneMenu styleClass="selectOneMenu" id="department1" value="#{pc_EmployeeAdd.employee.department}"> <f:selectItems value="#{DepartmentManager.departmentSelectList}" id="selectItems1"></f:selectItems> </h:selectOneMenu></td> </tr> package rts.entities.controller; import com.ibm.jpa.web.JPAManager; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import com.ibm.jpa.web.NamedQueryTarget; import com.ibm.jpa.web.Action; import javax.persistence.PersistenceUnit; import javax.annotation.Resource; import javax.transaction.UserTransaction; import rts.entities.Department; import java.util.List; import javax.persistence.Query; import java.util.ArrayList; import java.text.MessageFormat; import javax.faces.model.SelectItem; @SuppressWarnings("unchecked") @JPAManager(targetEntity = rts.entities.Department.class) public class DepartmentManager { ....... public List<SelectItem> getDepartmentSelectList() { List<Department> departmentList = getDepartment(); List<SelectItem> selectList = new ArrayList<SelectItem>(); MessageFormat mf = new MessageFormat("{0}"); for (Department department : departmentList) { selectList.add(new SelectItem(department, mf.format( new Object[] { department.getDeptname() }, new StringBuffer(), null).toString())); } return selectList; } Converter: package rts.entities.converter; import javax.faces.component.UIComponent; import javax.faces.context.FacesContext; import javax.faces.convert.Converter; import rts.entities.Department; import rts.entities.controller.DepartmentManager; import com.ibm.jpa.web.TypeCoercionUtility; public class DepartmentConverter implements Converter { public Object getAsObject(FacesContext facesContext, UIComponent arg1, String entityId) { DepartmentManager departmentManager = (DepartmentManager) facesContext .getApplication().createValueBinding("#{DepartmentManager}") .getValue(facesContext); int deptno = (Integer) TypeCoercionUtility.coerceType("int", entityId); Department result = departmentManager.findDepartmentByDeptno(deptno); return result; } public String getAsString(FacesContext arg0, UIComponent arg1, Object object) { if (object instanceof Department) { return "" + ((Department) object).getDeptno(); } else { throw new IllegalArgumentException("Invalid object type:" + object.getClass().getName()); } } } Method for Add button: public String createEmployeeAction() { EmployeeManager employeeManager = (EmployeeManager) getManagedBean("EmployeeManager"); try { employeeManager.createEmployee(employee); } catch (Exception e) { logException(e); } return ""; } faces-conf.xml <converter> <converter-for-class>rts.entities.Department</converter-for-class> <converter-class>rts.entities.converter.DepartmentConverter</converter-class> </converter> Stack trace javax.faces.FacesException: java.lang.NullPointerException at org.apache.myfaces.shared_impl.context.ExceptionHandlerImpl.wrap(ExceptionHandlerImpl.java:241) at org.apache.myfaces.shared_impl.context.ExceptionHandlerImpl.handle(ExceptionHandlerImpl.java:156) at org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:258) at javax.faces.webapp.FacesServlet.service(FacesServlet.java:191) at com.ibm.ws.webcontainer.servlet.ServletWrapper.service(ServletWrapper.java:1147) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:722) at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:449) at com.ibm.ws.webcontainer.servlet.ServletWrapperImpl.handleRequest(ServletWrapperImpl.java:178) at com.ibm.ws.webcontainer.filter.WebAppFilterManager.invokeFilters(WebAppFilterManager.java:1020) at com.ibm.ws.webcontainer.servlet.CacheServletWrapper.handleRequest(CacheServletWrapper.java:87) at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:886) at com.ibm.ws.webcontainer.WSWebContainer.handleRequest(WSWebContainer.java:1655) at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:195) at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:452) at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewRequest(HttpInboundLink.java:511) at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.processRequest(HttpInboundLink.java:305) at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.ready(HttpInboundLink.java:276) at com.ibm.ws.tcp.channel.impl.NewConnectionInitialReadCallback.sendToDiscriminators(NewConnectionInitialReadCallback.java:214) at com.ibm.ws.tcp.channel.impl.NewConnectionInitialReadCallback.complete(NewConnectionInitialReadCallback.java:113) at com.ibm.ws.tcp.channel.impl.AioReadCompletionListener.futureCompleted(AioReadCompletionListener.java:165) at com.ibm.io.async.AbstractAsyncFuture.invokeCallback(AbstractAsyncFuture.java:217) at com.ibm.io.async.AsyncChannelFuture.fireCompletionActions(AsyncChannelFuture.java:161) at com.ibm.io.async.AsyncFuture.completed(AsyncFuture.java:138) at com.ibm.io.async.ResultHandler.complete(ResultHandler.java:204) at com.ibm.io.async.ResultHandler.runEventProcessingLoop(ResultHandler.java:775) at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:905) at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1650) Caused by: java.lang.NullPointerException at rts.entities.converter.DepartmentConverter.getAsString(DepartmentConverter.java:29) at org.apache.myfaces.shared_impl.renderkit.RendererUtils.getConvertedStringValue(RendererUtils.java:656) at org.apache.myfaces.shared_impl.renderkit.html.HtmlRendererUtils.getSubmittedOrSelectedValuesAsSet(HtmlRendererUtils.java:444) at org.apache.myfaces.shared_impl.renderkit.html.HtmlRendererUtils.internalRenderSelect(HtmlRendererUtils.java:421) at org.apache.myfaces.shared_impl.renderkit.html.HtmlRendererUtils.renderMenu(HtmlRendererUtils.java:359) at org.apache.myfaces.shared_impl.renderkit.html.HtmlMenuRendererBase.encodeEnd(HtmlMenuRendererBase.java:76) at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:519) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:626) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:622) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:622) at javax.faces.component.UIComponent.encodeAll(UIComponent.java:622) at org.apache.myfaces.view.facelets.FaceletViewDeclarationLanguage.renderView(FaceletViewDeclarationLanguage.java:1320) at org.apache.myfaces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:263) at org.apache.myfaces.lifecycle.RenderResponseExecutor.execute(RenderResponseExecutor.java:85) at org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:239) ... 24 more