spring mvc autowired sessionFactory gives null object

Question

in spring mvc autowired sessionFactory gives null object. but the same procedu worked for me but this time it does not .please have a look at my code

spring-servlet.xml file

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans 
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/tx 
        http://www.springframework.org/schema/tx/spring-tx.xsd">    

    <!-- Add support for component scanning -->  
    <context:component-scan base-package="com.loveTodo.springPractice" >

  </context:component-scan>   

    <!-- Add support for conversion, formatting and validation support -->
    <mvc:annotation-driven/>

    <!-- Define Spring MVC view resolver -->  
    <bean
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/view/" />
        <property name="suffix" value=".jsp" />     
    </bean> 
<mvc:resources mapping="/resources/**" location="/resources/" /> 
    <!-- Step 1: Define Database DataSource / connection pool -->
    <bean id="myDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
          destroy-method="close">
        <property name="driverClass" value="com.mysql.jdbc.Driver" />
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/hb_student_tracker?useSSL=false" />
        <property name="user" value="hbstudent" />
        <property name="password" value="hbstudent" /> 

        <!-- these are connection pool properties for C3P0 -->  
        <property name="minPoolSize" value="5" />  
        <property name="maxPoolSize" value="20" />
        <property name="maxIdleTime" value="30000" />   
    </bean>  

    <!-- Step 2: Setup Hibernate session factory --> 
    <bean id="sessionFactory"
        class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
        <property name="dataSource" ref="myDataSource" />
        <property name="packagesToScan" value="com.loveTodo.springPractice.entity" />  
        <property name="hibernateProperties">  
           <props>  
              <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>  
              <prop key="hibernate.show_sql">true</prop>
           </props>
        </property>
   </bean>    

    <!-- Step 3: Setup Hibernate transaction manager -->
    <bean id="myTransactionManager"
            class="org.springframework.orm.hibernate5.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory"/>
    </bean>

    <!-- Step 4: Enable configuration of transactional behavior based on annotations -->
    <tx:annotation-driven transaction-manager="myTransactionManager" />

</beans>

my controller class

   package com.loveTodo.springPractice.controller;

import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

import com.loveTodo.springPractice.dao.imp.SpringFormLoginDAOImpl;
import com.loveTodo.springPractice.dao.inter.SpringFormLoginDAOInter;
import com.loveTodo.springPractice.entity.StudentLogin;


@RestController
@RequestMapping("/loginController")
public class SpringFormLoginController {

    @RequestMapping(value = "/authencateUser", method={RequestMethod.GET,RequestMethod.POST})
    public String authencateUser(@ModelAttribute("StudentLogin") StudentLogin theStudent) {

        String statusMessage=""; 
        // log the input data
    String username= theStudent.getUserName();
    String pwd= theStudent.getPassword();


    System.out.println(username);

    SpringFormLoginDAOInter daoObj=new SpringFormLoginDAOImpl(); 
    boolean validateUSer= daoObj.authencateUser(username, pwd);

    if(validateUSer)
    {   
        statusMessage="hello"+username;
    }

        return statusMessage;      
    }
}

DAO interface

package com.loveTodo.springPractice.dao.inter;




public interface SpringFormLoginDAOInter 
{


    boolean authencateUser(String userName,String password);

}

and the DAO implementation class

package com.loveTodo.springPractice.dao.imp;

import java.util.List;

import javax.transaction.Transactional;

import org.hibernate.Session;
import org.hibernate.SessionFactory;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import com.loveTodo.springPractice.dao.inter.SpringFormLoginDAOInter;
import com.loveTodo.springPractice.entity.StudentLogin;

@Repository
public class SpringFormLoginDAOImpl implements SpringFormLoginDAOInter 
{
    @Autowired  
    private SessionFactory sessionFactory;
    @Transactional
    @Override
    public boolean authencateUser(String userName, String password)  
    {
        Session currentSession=sessionFactory.getCurrentSession();
        System.out.println(currentSession);   
        boolean userStatus=false;  
        try {    

            if(userName !=null && password !=null)  
            {

                System.out.println("before");
                List<StudentLogin>  list=currentSession.createQuery("from StudentLogin where userName = :userName and password = :password ",StudentLogin.class).setParameter(1, userName)
                        .setParameter(2, password).list();   
                    if(!list.isEmpty())   
                    {         
                        userStatus=true;  
                    }   

                    System.out.println("after");

                    }  
        }  

    catch (Exception e) {
        e.printStackTrace();
    }


        return userStatus;
    }

}

and the exception

Apr 16, 2018 2:01:23 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [spring] in context with path [/springPractice] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause
java.lang.NullPointerException
    at com.loveTodo.springPractice.dao.imp.SpringFormLoginDAOImpl.authencateUser(SpringFormLoginDAOImpl.java:25)
    at com.loveTodo.springPractice.controller.SpringFormLoginController.authencateUser(SpringFormLoginController.java:31)
    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.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
    at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1100)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:687)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)

i have googled it tried a lot but not able to trace the problem and i am new to spring please , help me out

Answer 1

Remove this line

SpringFormLoginDAOInter daoObj=new SpringFormLoginDAOImpl(); 

and autowire your SpringFormLoginDAOInter in the controller.

Answer 2

In Controller I see this :

SpringFormLoginDAOInter daoObj=new SpringFormLoginDAOImpl(); 

You have to use autowiring for dao's. That is the whole point of using Spring - using Dependency Injection.

changes to be made:

1. add @Repository above SpringFormLoginDAOInter class.
2. Used autowired SpringFormLoginDAOInter object in controller just like you have used SessionFactory in Dao class.

Happy Coding! PS: you need to take care of naming conventions :)