org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [LoginHibernateDao

[Monica Shiralkar]

I am getting below error message while attempting spring IOC:
org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [LoginHibernateDaoImpl] for bean with name 'loginHibernateDaoImpl' defined in class path resource [ApplicationContext.xml]; nested exception is java.lang.ClassNotFoundException: LoginHibernateDaoImpl
org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1262)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:576)
org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1331)
org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:897)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:566)



LoginHibernteDaoImpl.java

package com.dao;


import java.util.List;

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

import com.model.User;

public class LoginHibernateDaoImpl implements LoginDao{


   
	public User authenticateUsers(String userName,String password) {
		
		List <User> login = null;
		 Session session = HibernateUtil.getSessionFactory().getCurrentSession();
	        Transaction tx=null;
	        try
	        {
	            tx = session.beginTransaction();
	          login=(List<User>) session.createQuery("from User where userName='"+userName+"'   and password='"+password+"'").list();
	            
	            tx.commit();
	        }
	        catch (RuntimeException e)
	        {
	        System.out.println(e);
	        }
	        finally
	        {
	        	try{
	            session.close();
	        	}
	        	catch(Exception e)
	        	{
	        		
	        	}
	        }
		if (login.size()>0)
			
			return login.get(0);
		else
		return null;
		
			
		
	}
	
	public static void main(String args[])
	{
		
	
	User user=new LoginHibernateDaoImpl().authenticateUsers("uname1", "secret");
	
	

	    }

}

Application Context.xml

<?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:mvc="http://www.springframework.org/schema/mvc"
  xmlns:context="http://www.springframework.org/schema/context"
  xsi:schemaLocation="
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
 
  

<bean id="loginHibernateDaoImpl" class="LoginHibernateDaoImpl"> 
</bean>


<bean id="service" class="LoginAction"> 
<property name="dao">
<ref local="loginHibernateDaoImpl"></ref>
</property>
</bean>
</beans>

LoginAction.java

package com.web;

import org.springframework.beans.factory.BeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.dao.LoginDao;
import com.dao.LoginHibernateDaoImpl;
import com.model.User;
import com.opensymphony.xwork2.ActionSupport;

public class LoginAction extends ActionSupport{
	
	private String username;
	private String password;
	
	LoginDao dao;

	public String getUsername() {
		return username;
	}

	public String getPassword() {
		return password;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	public String execute()
	{
		
		 ApplicationContext appContext = new ClassPathXmlApplicationContext("/ApplicationContext.xml");
		    BeanFactory factory = appContext;
		    LoginAction temp = (LoginAction)(factory.getBean("service"));
		  
		  
		
		//LoginDao dao=new LoginHibernateDaoImpl();
		User user=dao.authenticateUsers(username, password);
		if(user!=null)
			
		return "success";
		else
			return "error";
		
		
	}

}

thanks

[Balaji Vankadaru]

Do you have Your Login Dao interface and User Model Object present in the class library?

[Saif Asif]

Its a simple ClassNotFoundException , meaning your problem lies in just defining proper classpaths to the classes. Try to give fully qualified class names in the bean declaration in the applicationContext.xml.

[Balaji Vankadaru]

Oh yeah you need to give complete details of your class along with package name.

[Monica Shiralkar]

thanks.I got rid of that error.However now I am facing another issue. The dao which should be set by the Spring IOC is coming null. Here is my entire code:

ApplicationContext.xml

<?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:mvc="http://www.springframework.org/schema/mvc"
  xmlns:context="http://www.springframework.org/schema/context"
  xsi:schemaLocation="
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
 
  

<bean id="loginHibernateDaoImpl" class="com.dao.LoginHibernateDaoImpl"> 
</bean>


<bean id="service" class="com.web.LoginAction"> 
<property name="dao">
<ref local="loginHibernateDaoImpl"></ref>
</property>
</bean>
</beans>

LoginDao.java

package com.web;

import org.springframework.beans.factory.BeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.dao.LoginDao;
import com.dao.LoginHibernateDaoImpl;
import com.model.User;
import com.opensymphony.xwork2.ActionSupport;

public class LoginAction extends ActionSupport{
	
	private String username;
	private String password;
	
	LoginDao dao;

	
	public void setDao(LoginDao dao) {
		this.dao = dao;
	}

	public String getUsername() {
		return username;
	}

	public String getPassword() {
		return password;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	public String execute()
	{
		
		 ApplicationContext appContext = new ClassPathXmlApplicationContext("/ApplicationContext.xml");
		    BeanFactory factory = appContext;
		    LoginAction temp = (LoginAction)(factory.getBean("service"));
		  
		  
		
		//LoginDao dao=new LoginHibernateDaoImpl();
		User user=dao.authenticateUsers(username, password);
		if(user!=null)
			
		return "success";
		else
			return "error";
		
		
	}

}

In the above dao is comming null.

package com.dao;


import java.util.List;

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

import com.model.User;

public class LoginHibernateDaoImpl implements LoginDao{


   
	public User authenticateUsers(String userName,String password) {
		
		List <User> login = null;
		 Session session = HibernateUtil.getSessionFactory().getCurrentSession();
	        Transaction tx=null;
	        try
	        {
	            tx = session.beginTransaction();
	          login=(List<User>) session.createQuery("from User where userName='"+userName+"'   and password='"+password+"'").list();
	            
	            tx.commit();
	        }
	        catch (RuntimeException e)
	        {
	        System.out.println(e);
	        }
	        finally
	        {
	        	try{
	            session.close();
	        	}
	        	catch(Exception e)
	        	{
	        		
	        	}
	        }
		if (login.size()>0)
			
			return login.get(0);
		else
		return null;
		
			
		
	}


}

I am doing some small mistake because of which dao is getting set as null.

thanks

[Saif Asif]

There can be multiple possibilities for the cause of the null value returned from the DAO. The primary and fore-most reason would be that the query returned no record at all that matched your criteria of the username and password which you provided.
So I want you to check the following things for me

1. Make sure an entry exists in your DB for the userName and password that you are providing.
2. Check that the LoginAction class is receiving the correct values in the userName and password fields., just print them in the class to make sure that the values are there and correct.
3. Next , debug the DAOImpl class to make sure that the Query is returning any tuple at all .


Do post back for any further queries.

[Monica Shiralkar]

Thanks but what the query returns has no effect on the issue.

I am talking of stage lot before the query returns.

The dao variable should be populated with a value: object of type LoginHibernateDaoImpl.Thats how spring IOC should work.

What I am trying to achieve is the functionality

 //LoginDao dao=new LoginHibernateDaoImpl(); 

This line of code I should be able to do with spring IOC (without doing this tight coupling)

Hence dao should be populated with object of type LoginHibernateDaoImpl(). but for some reason spring IOC is not working and dao is null.


thanks

[Monica Shiralkar]

I tried drilled down to the problem area and it is the below code which is having some mistake:

 ApplicationContext appContext = new ClassPathXmlApplicationContext("/ApplicationContext.xml");
		    BeanFactory factory = appContext;
		    LoginAction temp = (LoginAction)(factory.getBean("service"));
		  

before this I have created a field with setter method:

LoginDao dao;
	public void setDao(LoginDao dao) {
		this.dao = dao;
	}

and my ApplicationContext.xml is as:

<bean id="loginHibernateDaoImpl" class="com.dao.LoginHibernateDaoImpl"> 
</bean>
<bean id="service" class="com.web.LoginAction"> 
<property name="dao">
<ref local="loginHibernateDaoImpl"></ref>
</property>
</bean>

In the above code where I am going wrong that the value of dao is coming null? Please advice.Thanks.

[Monica Shiralkar]

Thanks all.Its working now.