NullPointerException error when injecting EJB annotation

Question

First of all i am sorry about my bad english. When i create an object from KisiDao class and i try to use is it i get error "NullPointerException". I searched this error on this website but i couldn't find.

Kisi.java

package model;

import java.io.Serializable;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity
public class Kisi implements Serializable {

    private static final long serialVersionUID = -1527914551724665414L;

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE)
    private Integer id;

    private String adi;

    private String soyadi;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getAdi() {
        return adi;
    }

    public void setAdi(String adi) {
        this.adi = adi;
    }

    public String getSoyadi() {
        return soyadi;
    }

    public void setSoyadi(String soyadi) {
        this.soyadi = soyadi;
    }



}

KisiDao.java

package dao;

import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import model.Kisi;

@Stateless
public class KisiDao {


    @PersistenceContext
    private EntityManager entityManager;

    public Kisi KisiKaydet(Kisi kisi)
    {
        entityManager.persist(kisi);
        return kisi;
    }
}

KisiService.java

package service;

import java.io.Serializable;

import javax.annotation.PostConstruct;
import javax.ejb.EJB;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;

import model.Kisi;
import dao.KisiDao;

@ManagedBean(name="kisiService")
@ViewScoped
public class KisiService implements Serializable{

    private static final long serialVersionUID = -9027472804586886314L;

    @EJB
    private KisiDao kisiDao;

    private Kisi kisi = new Kisi();

    public void KisiKaydet()
    {
        kisiDao.KisiKaydet(kisi); //NullPointerException here
    }
    public Kisi getKisi() {
        return kisi;
    }

    public void setKisi(Kisi kisi) {
        this.kisi = kisi;
    }

}

This is console log.

WARNING: java.lang.NullPointerException
javax.el.ELException: java.lang.NullPointerException
    at org.apache.el.parser.AstValue.invoke(AstValue.java:258)
    at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:277)
    at javax.faces.event.MethodExpressionActionListener.processAction(MethodExpressionActionListener.java:149)
    at javax.faces.event.ActionEvent.processListener(ActionEvent.java:88)
    at javax.faces.component.UIComponentBase.broadcast(UIComponentBase.java:818)
    at javax.faces.component.UICommand.broadcast(UICommand.java:300)
    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.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:506)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:537)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1081)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:658)
    at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1566)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1523)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
    at service.KisiService.KisiKaydet(KisiService.java:25)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.apache.el.parser.AstValue.invoke(AstValue.java:245)
    ... 33 more

Answer 1

Looks like you are using Tomcat. Tomcat by default doesn't support EJBs, thats why it is null. If you are looking for lightweight server with EJB support check WebSphere Liberty https://developer.ibm.com/wasdev/