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Thread: Problems with ArrayList- gives me a NullPointerException and the program crashes

  1. #1
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    Default Problems with ArrayList- gives me a NullPointerException and the program crashes

    public Flask[] getArtifactsByBrand(String name){
        	 Flask[] myArray = new Flask[flasks.size()];
        	 Iterator<Flask> it= flasks.iterator();
     
        	  while(it.hasNext()){
     
                      System.out.print(it.next());
     
        	 }   
     
        	 if(flasks.contains(name)) {
        		 for(int i=0; i<myArray.length; i++) {
     
               	  System.out.println(myArray[i].toString());
               	  System.out.println(flasks.toString());
     
                   }
        	 } 
                   else {
                	   System.out.println("No flasks found");
                   }
     
    		 return myArray;     
     
         }

    Well, this is my code. Now, I want to search for the brand name in the arraylist. When I search for the brand. it gives me the result and then the program crashes. Its gives me an NullPointerException.(I am guessing nothing's there) PLEASE HELP..I have been stuck on this problem for a whole

    Enter Brand: ARgos
    Flask [brand=ARgos, includedCups=9, isWatertight=true, capacity=9.0, intendedLiquid=water, hasInsulation=true, netWeight=9.0, isExhibited=false]No flasks found
     
     
    Exception in thread "main" java.lang.NullPointerException
    	at museum.MuseumApplication.searchByBrand(MuseumApplication.java:160)
    	at museum.MuseumApplication.run(MuseumApplication.java:54)
    	at museum.MuseumApplication.main(MuseumApplication.java:31)


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: Problems with ArrayList- gives me a NullPointerException and the program crashes

    Its gives me an NullPointerException
    Please copy the full text of the error message and paste it here. It has important info about the error.

    Please edit your post and wrap your code with code tags:
    [code=java]
    <YOUR CODE HERE>
    [/code]
    to get highlighting and preserve formatting.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: Problems with ArrayList- gives me a NullPointerException and the program crashes

    I have posted the error above along with the code

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    Default Re: Problems with ArrayList- gives me a NullPointerException and the program crashes

    Exception in thread "main" java.lang.NullPointerException
    at museum.MuseumApplication.searchByBrand(MuseumAppli cation.java:160)
    There is a variable with a null value on line 160. Look at line 160 in the your source and see what variable is null. Then backtrack in the code to see why that variable does not have a valid value.
    If you can not tell which variable it is, add a println just before line 160 and print out the values of all the variables on that line.
    If you don't understand my answer, don't ignore it, ask a question.

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    Default Re: Problems with ArrayList- gives me a NullPointerException and the program crashes

    Well, The code in the museum application is correct. There should be nothing wrong with that. This is actually a project.they gave us a half written application. The code in the museumApplication was all written by the teachers. We just have to complete the methods the Museum.java. When I asked my teacher baou thr "NullPointerException" error he said, its because there is nothing in myArray. But, I wasn't sure what to do.

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    Default Re: Problems with ArrayList- gives me a NullPointerException and the program crashes

    Did you find the variable with the null value? You need to find that first. When you have found the variable with the null value, then figure out why that variable does not have a valid value.
    If you don't understand my answer, don't ignore it, ask a question.

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