java.lang.NullPointerException in JUnit Parameterized.class

[vastyjay]

Hi guys, I hope somebody can guide me as to where I am going wrong with the code below.
I'm quite new to Java.
Basically I'm trying to run a JUnit parametrized class in Eclipse which reads in the parameters from a tab delimited file.
However I'm getting java.lang.NullPointerException error message.
This is occurring at the line "return calculate.readTabDelimFile(("C:\\JAVA LEARNING\\calculateNumbers.tab"))".
I have the method readTabDelimFile in the class CalculateForm.java

I've imported all the relevant classes and packages.

@RunWith(Parameterized.class)
public class CalculateTwoNumbersTests {

	static SeleniumManager sm;
	static Selenium selenium;
	static CalculateForm calculate;
	
	private String number1;
	private String function;
	private String number2;
	private String answer;
	
	@BeforeClass
	static public void startServer() throws IOException{
		 sm = new SeleniumManager();
		 sm.start("http://www.compendiumdev.co.uk");
		 selenium = sm.getSelenium();
	}
	
	@AfterClass
	static public void stopServer(){
		sm.stop();
	}
		
      public CalculateTwoNumbersTests(String num1, String function, String num2, String answer){
    	this.number1 = num1;
    	this.function = function;
    	this.number2 = num2;
    	this.answer = answer;
    }	

 
    @Parameters
    public static Collection data() throws NumberFormatException, IOException {
       [B] return calculate.readTabDelimFile(("C:\\JAVA LEARNING\\calculateNumbers.tab"));[/B]

    }
    
	@Test
	public void test_calculate_two_values() throws InterruptedException{	
		calculate = new CalculateForm(selenium);
		calculate.open();
		
		calculate.setNumber1(this.number1);
		calculate.setFunction(this.function);
		calculate.setNumber2(this.number2);
		
		calculate = calculate.doCalculation();
		assertEquals(this.answer,calculate.getAnswer());
		
	}
}

Below is the method readTabDelimFile which is in the class CalculateForm.java

public Collection<String[]> readTabDelimFile(String filename)
        	throws NumberFormatException, IOException {
    		ArrayList<String[]> lines = new ArrayList<String[]>();
    		BufferedReader fh = new BufferedReader(new FileReader(filename));
    		String s;
    		
    		while ( (s=fh.readLine())!=null) {
    			String f[] = s.split("\t");
    			lines.add(f);
    		}
    		fh.close();
    		return lines;
    		
        }

Any help in rectifying this will be greatly appreciated.

Thanks
Vasty

[Tolls]

And after you've wrapped your code in [code] tags [/code], what is the full exception, including stack trace?

[vastyjay]

Thanks for your response, below is the full stack trace:

java.lang.NullPointerException
at com.automation.seleniumtutorials.chap31.CalculateT woNumbersTests.data(CalculateTwoNumbersTests.java: 74)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Nativ e Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknow n Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Un known Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runRefle ctiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallabl e.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExpl osively(FrameworkMethod.java:44)
at org.junit.runners.Parameterized.allParameters(Para meterized.java:292)
at org.junit.runners.Parameterized.<init>(Parameteriz ed.java:282)
at sun.reflect.NativeConstructorAccessorImpl.newInsta nce0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInsta nce(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newI nstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at org.junit.internal.builders.AnnotatedBuilder.build Runner(AnnotatedBuilder.java:29)
at org.junit.internal.builders.AnnotatedBuilder.runne rForClass(AnnotatedBuilder.java:21)
at org.junit.runners.model.RunnerBuilder.safeRunnerFo rClass(RunnerBuilder.java:59)
at org.junit.internal.builders.AllDefaultPossibilitie sBuilder.runnerForClass(AllDefaultPossibilitiesBui lder.java:26)
at org.junit.runners.model.RunnerBuilder.safeRunnerFo rClass(RunnerBuilder.java:59)
at org.junit.internal.requests.ClassRequest.getRunner (ClassRequest.java:26)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestR eference.<init>(JUnit4TestReference.java:33)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestC lassReference.<init>(JUnit4TestClassReference.java :25)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestL oader.createTest(JUnit4TestLoader.java:48)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestL oader.loadTests(JUnit4TestLoader.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRu nner.runTests(RemoteTestRunner.java:452)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRu nner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRu nner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRu nner.main(RemoteTestRunner.java:197)

[Tolls]

'calculate' is null.
You only seem to initialise it in the test method, which is run after all the setup is complete, including @Parameter annotations.

[vastyjay]

Can you give me an example of how you will fix this

Thanks

[Tolls]

No idea.
I don't know what the test is, what the code is supposed to do that it is testing, what a reasonable pre-test set up would look like...anything that would allow me to give a reasonable answer.

I've pointed out where your error lies, so you now need to figure out how to fix it with respect to your test/code.

[vastyjay]

Will appreciate sample solutions from forum members.

[wsaryada]

Thanks for your response, below is the full stack trace:

java.lang.NullPointerException
at com.automation.seleniumtutorials.chap31.CalculateT woNumbersTests.data(CalculateTwoNumbersTests.java: 74)

You can check what's producing the error in the CalculateTwoNumbersTests.java line number 74.