I am having problem with getting data from the database (JavaDB). Exactly, I think the error is in the UserBean class in the method GetAllUsersFromTable. It is maybe bc I get entities incorrectly from the database. I have tried to write method GetAllUsersFromTable in few different ways but it doesn't work well.
My project works well until I don't try to get the data from the database. index page is displayed correctly, usersForm also display correctly and when I click submit button it display error. On the page were the error is displayed I should see table with all users.
I use the Glassfish 4.0 and JavaDB is build in. I don't use any IDE's like Eclipse or Netbeans. My project is managed by Maven.I use also JSF CDI ManagedBeans and JPA.
Please ask me any question. I would really love to solve this issue.
I get this error:
javax.faces.el.EvaluationException: java.lang.NullPointerException
at
javax.faces.component.MethodBindingMethodExpressionAdapter.invoke
(MethodBindingMethodExpressionAdapter.java:101)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
at javax.faces.component.UICommand.broadcast(UICommand.java:315)
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:790)
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1282)
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:646)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:357)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:260)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:188)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at
org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
at
org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
at
org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
at
org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.
run(WorkerThreadIOStrategy.java:135)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.
doWork(AbstractThreadPool.java:564)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
at java.lang.Thread.run(Thread.java:744)
Caused by: java.lang.NullPointerException
at com.test.UserBean.getAllUsersFromTable(UserBean.java:119)
at com.test.UserBean$Proxy$_$$_WeldClientProxy.getAllUsersFromTable(Unknown Source)
at com.test.AllUsersBean.add(AllUsersBean.java:43)
at com.test.AllUsersBean$Proxy$_$$_WeldClientProxy.add(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at javax.el.ELUtil.invokeMethod(ELUtil.java:326)
at javax.el.BeanELResolver.invoke(BeanELResolver.java:536)
at javax.el.CompositeELResolver.invoke(CompositeELResolver.java:256)
at com.sun.el.parser.AstValue.invoke(AstValue.java:269)
at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:304)
at org.jboss.weld.util.el.ForwardingMethodExpression.invoke(ForwardingMethodExpression.java:40)
at org.jboss.weld.el.WeldMethodExpression.invoke(WeldMethodExpression.java:50)
at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
at
javax.faces.component.MethodBindingMethodExpressionAdapter.invoke
(MethodBindingMethodExpressionAdapter.java:87)
... 35 more
Line 119 in the UserBean.java file is
user.setId(v.getId());
package com.test;
/*Importing required java libraries */
import java.io.Serializable;
import javax.inject.Named;
import javax.inject.Inject;
import javax.enterprise.context.ApplicationScoped;
import java.util.ArrayList;
import java.util.List;
@Named("appBean")
@ApplicationScoped
public class AllUserssBean implements Serializable {
private List<UserBean> users;
private int id;
@Inject
private UserBean subBean;
public AllUsersBean(){
users = new ArrayList<UserBean>();
id = 0;
}
public String add() throws Exception {
subBean.addUserToTable();
++id;
users.add(subBean.getAllUsersFromTable(id));
subBean.reset();
return "submit";
}
/*Get total number of users */
public int getTotal(){ return users.size(); }
public List<UserBean> getUsers() { return users; }
public void setUsers(List<UserBean> users) { this.users = users; }
}
package com.test;
/*Importing required java libraries */
import java.io.Serializable;
import javax.inject.Named;
import javax.enterprise.context.SessionScoped;
import java.sql.*;
import javax.annotation.Resource;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.persistence.PersistenceUnit;
import javax.transaction.UserTransaction;
import javax.transaction.RollbackException;
import javax.persistence.*;
import java.util.List;
import java.util.*;
@Named("subBean")
@SessionScoped
public class UserBean implements Serializable{
@PersistenceUnit(unitName="testMe")
private EntityManagerFactory emf;
@Resource
private UserTransaction transaction;
private int id;
private String fname;
private String lname;
public UserBean() {
this.fname = "";
this.lname = "";
}
public int getId() { return id; }
public void setId(int id) { this.id = id; }
public String getFname() { return fname; }
public void setFname(String fname) { this.fname = fname; }
public String getLname() { return lname; }
public void setLname(String lname) { this.lname = lname; }
public UserTransaction getTransaction() { return transaction; }
public void setTransaction(UserTransaction transaction) { this.transaction = transaction; }
public void addUserToTable() throws Exception
{
EntityManager manager = emf.createEntityManager();
boolean commit;
try{
transaction.begin();
manager.joinTransaction();
commit = false;
try {
User v = null;
v.setFname(fname);
v.setLname(lname);
manager.persist(v);
transaction.commit();
commit = true;
}finally {
if(commit==false){
transaction.rollback();
}
}
} catch(Exception e) {
e.printStackTrace();
}finally {
manager.close();
}
}
public UserBean getAllUsersFromTable(int id) {
EntityManager manager = emf.createEntityManager();
User v = null;
UserBean user = new UserBean();
try {
v = manager.find(User.class, id);
user.setId(v.getId());
user.setFname(v.getFname());
user.setLname(v.getLname());
}finally {
manager.close();
}
return user;
}
/*
public List getAllUsersFromTable() throws javax.transaction.SystemException,
javax.transaction.NotSupportedException {
EntityManager manager = emf.createEntityManager();
User v = null;
List<User> results;
try {
TypedQuery<User> query =
manager.createQuery("SELECT * FROM User", User.class);
results = query.getResultList();
}finally {
manager.close();
}
return results;
} */
/*reset method is used to set all the parameters to null and
to 0. This method is called after user was added to the
list of users */
public void reset(){
setFname("");
setLname("");
}
}
package com.test;
/*Importing required java libraries */
import java.io.Serializable;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
import javax.persistence.EntityManager;
import javax.persistence.Entity;
import javax.persistence.Column;
import javax.persistence.Id;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
@Entity
public class User implements Serializable{
@Id
@GeneratedValue
private int id;
private String fname;
private String lname;
public User() {}
public int getId() { return id; }
public void setId(int id) { this.id = id; }
public String getFname() { return fname; }
public void setFname(String fname) { this.fname = fname; }
public String getLname() { return lname; }
public void setLname(String lname) { this.lname = lname;}
}
index.xhtml
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xml:lang="en" lang="en"
xmlns="http://www.w3.org/1999/xhtml"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:ui="http://java.sun.com/jsf/facelets">
<h:head><title></title></h:head>
<h:body>
<div style="text-align:center">
<h1>Hello</h1>
<p><h:link value="User Form" outcome="userForm"/></p>
<p><h:link value="All users List" outcome="allUsersList"/></p>
</div>
</h:body>
</html>
userForm.xhtml
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xml:lang="en" lang="en"
xmlns="http://www.w3.org/1999/xhtml"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:ui="http://java.sun.com/jsf/facelets">
<h:head>
<h:outputStylesheet library="css" name="template.css"/>
<title>User Form page</title>
</h:head>
<h:body>
<h:form id="submissionForm">
<table border="0">
<tr>
<td><h:outputLabel for="fname" value="First name:"></h:outputLabel></td>
<td><h:inputText id="firstName" value="#{subBean.fname}" maxlength="30"
requiredMessage="Please enter first name!" validatorMessage="First
name can include only letters. You can't live it empty!" >
<f:validateRegex pattern="[a-zA-Z]{1,30}"></f:validateRegex>
</h:inputText></td>
<td><h:message for="firstName" style="color:red;"></h:message></td>
</tr>
<tr>
<td><h:outputLabel for="lname" value="Last name:"></h:outputLabel></td>
<td><h:inputText id="lastName" value="#{subBean.lname}" maxlength="30"
requiredMessage="Please enter last name!" validatorMessage="Last
name can include only letters. You can't live it empty!" >
<f:validateRegex pattern="[a-zA-Z]{1,60}"></f:validateRegex>
</h:inputText></td>
<td><h:message for="lastName" style="color:red;"></h:message></td>
</tr>
<tr>
<td colspan="3">
<h:commandButton id="submit" value="Submit" action="#{appBean.add()}"
style="float:right;margin-right:10px;"/>
</td>
</tr>
</table>
</h:form>
</h:body>
</html>
allUsersForm.xhtml
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xml:lang="en" lang="en"
xmlns="http://www.w3.org/1999/xhtml"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:ui="http://java.sun.com/jsf/facelets">
<h:head>
<title>List of All Users page</title>
</h:head>
<h:body>
<h:form id="AllUsersListForm">
<h2><h:outputText value="The next election date: #{msgs.date}"/></h2><p></p>
<h:dataTable value="#{appBean.users}" var="v">
<h:column>
<f:facet name="header"><h:outputText value="Id"></h:outputText></f:facet>
<h:outputText value="#{v.id}"></h:outputText>
</h:column>
<h:column>
<f:facet name="header"><h:outputText value="First Name"></h:outputText></f:facet>
<h:outputText value="#{v.fname}"></h:outputText>
</h:column>
<h:column>
<f:facet name="header"><h:outputText value="Last Name"></h:outputText></f:facet>
<h:outputText value="#{v.lname}"></h:outputText>
</h:column>
<f:facet name="footer"><h:outputText
value="The total number of users: #{appBean.getTotal()}"></h:outputText>
</f:facet>
</h:dataTable>
<p></p>
<p><h:link value="Home page" outcome="index"/></p>
</h:form>
</h:body>
</html>
persistence.xml (It is placed under main/resources/META-iNF/perssitence.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="test1" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<jta-data-source>jdbc/username</jta-data-source>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="javax.persistence.schema-generation.database.action"
value="drop-and-create"/>
<property name="javax.persistence.schema-generation.create-source"
value="metadata"/>
<property name="javax.persistence.schema-generation.drop-source"
value="metadata"/>
<property name="javax.persistence.jdbc.user" value="Us"/>
<property name="javax.persistence.jdbc.password" value="Us"/>
</properties>
</persistence-unit>
</persistence>
When I go to (localhost:4848/common/index.jsf) I create JDBC Connection Pool and everything is correct. When I Ping I get success response I also create JDBC Connection Resource and everything is set up correctly
This is what we could use us an example to add data do database
public class AddingDatabase
{
@PersistenceUnit(unitName="test_db”) private EntityManagerFactory emf;
@Resource private UserTransaction utx;
void doDML(MyEntity e) throws SystemException, NotSupportedException,
javax.transaction.RollbackException,HeuristicMixedException,HeuristicRollbackException
{
EntityManager em = emf.createEntityManager();
utx.begin();
em.joinTransaction();
try {
boolean committed = false;
try {
em.persist(e);
utx.commit();
committed = true;
} finally {
if (!committed) utx.rollback();
}
}
finally {
em.close();
}
}
}
