Why CreateEntityManager returns NULL - mysql

Question

I am new to java technology so please excuse me if I present a silly problem...
I want to make a JSF 2.0 servlet and use MySql for database engine.
The problem is that it's seems that I can't connect to server.
I use netbeans IDE, and for guide I use a tutorial from youtube: http://www.youtube.com/watch?v=UBNaiVWwAZw&feature=related
The difference is that I use Tomcat.
My persistence.xml file is in Web/META-INF/persistence.xml and the content is:
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" 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_2_0.xsd">
<persistence-unit name="AnunturiJsfPU" transaction-type="RESOURCE_LOCAL">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<class>my.servlets.Users</class>
<class>my.servlets.UsersSessions</class>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/tz_cadastru_galati"/>
<property name="javax.persistence.jdbc.password" value=""/>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
<property name="javax.persistence.jdbc.user" value="root"/>
</properties>
</persistence-unit>
</persistence>
my servlet file is:
package my.servlets;
import java.io.IOException;
import java.io.PrintWriter;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.PersistenceUnit;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
#WebServlet(name = "testOkServlet2", urlPatterns = {"/testOkServlet2"})
public class testOkServlet2 extends HttpServlet {
#PersistenceUnit
EntityManagerFactory emf;
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
EntityManager em = emf.createEntityManager();
Users u = (Users) em.createNamedQuery("Users.findAll").getResultList().get(0);
String myUser = u.getUserNume();
out.println("User:" + myUser);
} catch (Exception e)
{
out.println(e.getMessage());
}
finally {
out.close();
}
}
#Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
#Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
#Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}
and this is my Users object:
package my.servlets;
import java.io.Serializable;
import java.util.Date;
import javax.persistence.Basic;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import javax.xml.bind.annotation.XmlRootElement;
#Entity
#Table(name = "users")
#XmlRootElement
#NamedQueries({
#NamedQuery(name = "Users.findAll", query = "SELECT u FROM Users u"),
#NamedQuery(name = "Users.findByUserID", query = "SELECT u FROM Users u WHERE u.userID = :userID"),
#NamedQuery(name = "Users.findByUserNume", query = "SELECT u FROM Users u WHERE u.userNume = :userNume"),
#NamedQuery(name = "Users.findByNumePrenume", query = "SELECT u FROM Users u WHERE u.numePrenume = :numePrenume"),
#NamedQuery(name = "Users.findByEmail", query = "SELECT u FROM Users u WHERE u.email = :email"),
#NamedQuery(name = "Users.findByParola", query = "SELECT u FROM Users u WHERE u.parola = :parola"),
#NamedQuery(name = "Users.findByContActiv", query = "SELECT u FROM Users u WHERE u.contActiv = :contActiv"),
#NamedQuery(name = "Users.findByDataAdaugarii", query = "SELECT u FROM Users u WHERE u.dataAdaugarii = :dataAdaugarii"),
#NamedQuery(name = "Users.findByNivelAccesID", query = "SELECT u FROM Users u WHERE u.nivelAccesID = :nivelAccesID")})
public class Users implements Serializable {
private static final long serialVersionUID = 1L;
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Basic(optional = false)
#Column(name = "userID")
private Integer userID;
#Basic(optional = false)
#Column(name = "userNume")
private String userNume;
#Basic(optional = false)
#Column(name = "numePrenume")
private String numePrenume;
#Basic(optional = false)
#Column(name = "email")
private String email;
#Basic(optional = false)
#Column(name = "parola")
private String parola;
#Basic(optional = false)
#Column(name = "contActiv")
private boolean contActiv;
#Basic(optional = false)
#Column(name = "dataAdaugarii")
#Temporal(TemporalType.TIMESTAMP)
private Date dataAdaugarii;
#Basic(optional = false)
#Column(name = "nivelAccesID")
private short nivelAccesID;
public Users() {
}
public Users(Integer userID) {
this.userID = userID;
}
public Users(Integer userID, String userNume, String numePrenume, String email, String parola, boolean contActiv, Date dataAdaugarii, short nivelAccesID) {
this.userID = userID;
this.userNume = userNume;
this.numePrenume = numePrenume;
this.email = email;
this.parola = parola;
this.contActiv = contActiv;
this.dataAdaugarii = dataAdaugarii;
this.nivelAccesID = nivelAccesID;
}
public Integer getUserID() {
return userID;
}
public void setUserID(Integer userID) {
this.userID = userID;
}
public String getUserNume() {
return userNume;
}
public void setUserNume(String userNume) {
this.userNume = userNume;
}
public String getNumePrenume() {
return numePrenume;
}
public void setNumePrenume(String numePrenume) {
this.numePrenume = numePrenume;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getParola() {
return parola;
}
public void setParola(String parola) {
this.parola = parola;
}
public boolean getContActiv() {
return contActiv;
}
public void setContActiv(boolean contActiv) {
this.contActiv = contActiv;
}
public Date getDataAdaugarii() {
return dataAdaugarii;
}
public void setDataAdaugarii(Date dataAdaugarii) {
this.dataAdaugarii = dataAdaugarii;
}
public short getNivelAccesID() {
return nivelAccesID;
}
public void setNivelAccesID(short nivelAccesID) {
this.nivelAccesID = nivelAccesID;
}
#Override
public int hashCode() {
int hash = 0;
hash += (userID != null ? userID.hashCode() : 0);
return hash;
}
#Override
public boolean equals(Object object) {
// TODO: Warning - this method won't work in the case the id fields are not set
if (!(object instanceof Users)) {
return false;
}
Users other = (Users) object;
if ((this.userID == null && other.userID != null) || (this.userID != null && !this.userID.equals(other.userID))) {
return false;
}
return true;
}
#Override
public String toString() {
return "my.servlets.Users[ userID=" + userID + " ]";
}
}
If I missed to post any other information please tell me and I will put it online.
Please help me.
Manny thanks in advance.

Answer 1

First thing to to in a situation like this is to check the connection to server manually to make sure that you have access to server.