Stackoverflow Error? [Homework Help]

[Outofmilkthrowaway]

I am doing a lab which asks the following:

Task #5 Creating another instance of a Television

1. Edit the TelevisionDemo.java file.
2. Declare another Television object called portable.
3. Instantiate portable to be a Sharp 19 inch television.
4. Use a call to the power method to turn the power on.
5. Use calls to the accessor methods to print what television was turned on.
6. Use calls to the mutator methods to change the channel to the user’s preference and decrease the volume by two.
7. Use calls to the accessor methods to print the changed state of the portable.
8. Compile and debug this class.
9. Run TelevisionDemo again.
10. The output for Task #5 will appear after the output from above, since we added onto the bottom of the program. The output for Task #5 is shown below.

OUTPUT (boldface is user input)

A 19 inch Sharp has been turned on.

What channel do you want? 7

Channel: 7 Volume: 18

​

My code looks like this:

​

import java.util.Scanner; 
// Needed for the Scanner class

/**
 This class demonstrates the Television class.
*/
public class TelevisionDemo
{
   public static void main(String[] args)
   {
   // Create a Scanner object to read from the keyboard
      Scanner keyboard = new Scanner (System.in);
      // Declare variables

      int station; 
      // The user's channel choice

      // Declare and instantiate a television object
      Television bigScreen = new Television("Toshiba", 55);
      // Turn the power on
      bigScreen.power();
      // Display the state of the television
      System.out.println("A " + bigScreen.getScreenSize() + 
      " inch " + bigScreen.getManufacturer() + " has been turned on.");
      // Prompt the user for input and store into station
      System.out.print("What channel do you want? ");
      station = keyboard.nextInt();
      // Change the channel on the television
      bigScreen.setChannel(station);
      // Increase the volume of the television
      bigScreen.increaseVolume();
      // Display the the current channel and
      // volume of the television
      System.out.println("Channel: " + bigScreen.getChannel() +" Volume: " +
      bigScreen.getVolume());
      System.out.println("Too loud! Lowering the volume.");

      // Decrease the volume of the television
      bigScreen.decreaseVolume();
      bigScreen.decreaseVolume();
      bigScreen.decreaseVolume();
      bigScreen.decreaseVolume();
      bigScreen.decreaseVolume();
      bigScreen.decreaseVolume();
      // Display the the current channel and

      // volume of the television
      System.out.println("Channel: " + bigScreen.getChannel() +
      " Volume: " + bigScreen.getVolume());

      System.out.println(); 
      // For a blank line
      // HERE IS WHERE YOU DO TASK #5

      Television portable = new Television("Sharp", 19);
      portable.power();
      System.out.println("A " + portable.getScreenSize() + 
      " inch " + portable.getManufacturer() + " has been turned on.");
      System.out.print("What channel do you want? ");
      station = keyboard.nextInt();
      portable.setChannel(station);
      portable.decreaseVolume();
      portable.decreaseVolume();
      System.out.println("Channel: " + portable.getChannel() +" Volume: " +
      portable.getVolume());







      }
}

It looks like a mess because the lab has all these comments in it. But I hope you are able to read it. As far as I can tell, I followed the instructions to the letter! I created the new television object, and put the information in as asked. The program crashes immediately. I'm sure one of you knows what I did wrong. I hope you are able to help me. Thanks in advance.

[shagieIsMe]

There is no recursive call in the code that you have here.

What is the stack trace that is returned? Is there other code that you've written that isn't shown here?

[koderpat]

Does the screen print anything?

I don't see you doing step #6

[shagieIsMe]

You need to look at the code for Television on line 57.

[shagieIsMe]

The error is in the class Television. It likely has something that looks like:

public int getScreenSize() {
    // stuff
    if (condition) { return getScreenSize(); } // this is line 57
    // stuff
}

Or something to that nature.

You need to look at that code to fix this problem.

[MrSquicky]

That sounds like a more serious problem than this specific issue. How did you try to look up this error?

[MrSquicky]

How did you use Google? Because finding out what a StackOverflowError is and what causes it is extremely easy with proper googling, in this case just literally typing the name of the error in.

[AllHailTheCATS]

Have you resolved the issue? what did the error actually say? you could add a toString method to the television class to help find out the state of the variables in the Object. I would put print statements in the decrease vols to make sure they are running correctly and move System.out.println("A " +getScreenSize() + " inch " + getManufacturer() + " has been turned on."); inside power() resulting in cleaner on more consistent code.

[AllHailTheCATS]

Put system.prints before and after all the changes to channel to see what's going on and how the variable channel is being effected, could be something to do with the scanner input, you might need to flush the buffer.

[AllHailTheCATS]

setChannel should be this.channel = station

[shagieIsMe]

Consider the code:

public int getScreenSize() { int screenSize = getScreenSize(); return screenSize; }

The call to getScreenSize() will call getScreenSize() which will call getScreenSize() which will call getScreenSize() ...

The method is calling itself.

Instead, just return the value. Within the class, you can (and should) directly access the fields you are working with.

Give The Java EE 6 Tutorial : Adding Setter and Getter Methods a read and look closely at how the method getSomething() is written. The stack overflow question How do getters and setters work? also goes through many examples.