NullPointer Exception while loading bean file through ClassPathXmlApplicationContext

[avinash.madireddy]

Hi,

I'm a beginner to spring. I'm getting a nullpointer exception while loading the bean class.

I loaded all the required spring jars.

Can any help me to solve this problem.


Project structure:

HellpSpring
-src
--com.tutorialspoint
---HelloWorld.java
---MainApp.java
--Beans-config.xml

Thank you!



Main file
-----------

package com.tutorialspoint;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlAp plicationContext;

public class MainApp {

public static void main(String[] args) {

ApplicationContext context = new ClassPathXmlApplicationContext("Beans-config.xml");

HelloWorld obj = (HelloWorld) context.getBean("helloWorld");

obj.getMessage();

}

}
-----
HelloWorld

package com.tutorialspoint;

public class HelloWorld
{
private String message;
public void setMessage(String message)
{
this.message = message;
}
public void getMessage()
{
System.out.println("Your Message : " + message);
}
}

----------
Beans-config.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:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schem...-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd">


<bean id="helloWorld" class="com.tutorialspoint.HelloWorld">

<property name="message" value="Hello World!"/>

</bean>

</beans>

--------

Error log

Oct 05, 2012 11:48:38 AM org.springframework.context.support.AbstractApplic ationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlAp plicationContext@35389244: startup date [Fri Oct 05 11:48:38 IST 2012]; root of context hierarchy
Exception in thread "main" java.lang.ExceptionInInitializerError
at org.springframework.context.support.AbstractRefres hableApplicationContext.createBeanFactory(Abstract RefreshableApplicationContext.java:195)
at org.springframework.context.support.AbstractRefres hableApplicationContext.refreshBeanFactory(Abstrac tRefreshableApplicationContext.java:128)
at org.springframework.context.support.AbstractApplic ationContext.obtainFreshBeanFactory(AbstractApplic ationContext.java:522)
at org.springframework.context.support.AbstractApplic ationContext.refresh(AbstractApplicationContext.ja va:436)
at org.springframework.context.support.ClassPathXmlAp plicationContext.<init>(ClassPathXmlApplicationCon text.java:139)
at org.springframework.context.support.ClassPathXmlAp plicationContext.<init>(ClassPathXmlApplicationCon text.java:83)
at com.tutorialspoint.MainApp.main(MainApp.java:10)
Caused by: java.lang.NullPointerException
at org.springframework.beans.factory.support.DefaultL istableBeanFactory.<clinit>(DefaultListableBeanFac tory.java:104)
... 7 more

[Marten Deinum]

Please use [ code][/code ] tags when posting code/xml/stacktrace so that they remain readable... Also post full stacktraces not snippets....

[avinash.madireddy]

 package com.tutorialspoint;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class MainApp {

	public static void main(String[] args) {
		
		ApplicationContext context = new ClassPathXmlApplicationContext("Beans-config.xml");
		
		HelloWorld obj = (HelloWorld) context.getBean("helloWorld");
		
		obj.getMessage();
		
	}
	
}

package com.tutorialspoint;

public class HelloWorld 
{ 
	private String message; 
	public void setMessage(String message)
	{ 
		this.message = message; 
	} 
	public void getMessage()
	{ 
		System.out.println("Your Message : " + message); 
	} 
}

<?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"
	xsi:schemaLocation="
		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="helloWorld" class="com.tutorialspoint.HelloWorld"> 

	 <property name="message" value="Hello World!"/> 
 
    </bean> 
 
 </beans>

Oct 05, 2012 2:39:28 PM org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@35389244: startup date [Fri Oct 05 14:39:28 IST 2012]; root of context hierarchy
Exception in thread "main" java.lang.ExceptionInInitializerError
	at org.springframework.context.support.AbstractRefreshableApplicationContext.createBeanFactory(AbstractRefreshableApplicationContext.java:195)
	at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:128)
	at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:522)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:436)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
	at com.tutorialspoint.MainApp.main(MainApp.java:10)
Caused by: java.lang.NullPointerException
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.<clinit>(DefaultListableBeanFactory.java:104)

[Marten Deinum]

Which spring version? Doesn't it work or does it simply log this message and continues... Please try to be a bit more informative else it will be guessing...

[avinash.madireddy]

I'm using spring-framework-3.1.0.M2 version.

When i try to compile the program it's displaying NullPointerException.

What i understood is..ApplicationContext is unable to find the bean file. The bean file is located under ../src folder.

[Marten Deinum]

Why are you using a milestone (i.e. beta) version instead of a final..

It has nothing to do with compilation you are already trying to start the application... The NullPointer, in general, shouldn't come from the fact that it cannot load the file (then you would get another exception). Also the exception occurs in a static initializer and not whilst loading the file.

Also make sure you are on java6 not 5 and for starters upgrade to spring 3.1.2 instead of the in between milestone version (and update your xsd in your file to 3.1 or remove the version altogether).

[avinash.madireddy]

I upgraded to spring 3.1.2.

I'm using jdk1.7.0_02 and jre7.

Still i'm getting the same problem.

it's showing error in MainApp.java in 10th line

		ApplicationContext context = new ClassPathXmlApplicationContext("Beans-config.xml");

[Marten Deinum]

it's showing error in MainApp.java in 10th line

No it's not, check again it is in the init block of DefaultListableBeanFactory...

Try JDK6 instead of 7, could be a problem...

[avinash.madireddy]

Can you explain me why JDK6 and not JDK7?

Features of JDK6 will also be available in JDK7!

[Marten Deinum]

The fact that features are available doesn't matter, there are several changes in JDK7 which might break things... So just give it a try to see if it helps..