Why won't this compile?

[degamer106]

This is a relatively simple program but for some reason, I can't compile it. I'm pretty sure the code is correct and working.

My compiler keeps saying that it cannot find a constructor matching a HourlyWorker constructor when I instantiate a HourlyWorker object. I've checked and rechecked the code (in WorkerTester and HourlyWorker classes) to make sure everything matches, but I can't find anything wrong.

Worker.java

public class Worker
{
	public Worker(String n, int r)
	{
		name = n;
		rate = r;
	}
	public double computePay(int hours)
	{
		return (rate * hours);
	}
	public int getRate()
	{
		return rate;
	}
	private String name;
	private int rate;
}

SalariedWorker

public class SalariedWorker extends Worker
{
	public SalariedWorker(String n, int r)
	{
		super(n, r);
	}
	public double computePay(int hours)
	{
		double totalPay = 0;

		totalPay = this.getRate() * 40;

		return totalPay;
	}
}

HourlyWorker.java

public class HourlyWorker extends Worker
{
	public HourlyWorker(String n, int r)
	{
		super(n, r);
	}
	public double computePay(int hours)
	{
		double totalPay = 0;

		if (hours >= 0 && hours <= 40)
			totalPay = this.getRate() * hours;
		else
			totalPay = this.getRate() * ((hours - 40) * 1.5 + 40);

		return totalPay;
	}
}

/**
This class tests class Worker and its subclasses.
*/
WorkerTester.java

public class WorkerTester
{
   public static void main(String[] args)
   {
      Worker s = new SalariedWorker("Sally", 40);
      Worker h = new HourlyWorker("Harry", 40);

      System.out.println(s.computePay(30));
      System.out.println("Expected: 1600");
      System.out.println(h.computePay(30));
      System.out.println("Expected: 1200");
      System.out.println(s.computePay(50));
      System.out.println("Expected: 1600");
      System.out.println(h.computePay(50));
      System.out.println("Expected: 2200");
   }
}

[masijade]

compile with

javac -classpath . <Classname>.java

[degamer106]

Still getting the same problem.

[Black Box]

I've copied your code and it works perfectly. How do you have your files organized?

Like this?
-WorkerDirectory
+ Worker.java
+ HourlyWorker.java
+ SalariedWorker.java
+ WorkerTester.java

Some package definitions lacking maybe?

Black Box

[masijade]

Show your exact directory structure, and the exact command you used to compile.

[degamer106]

Show your exact directory structure, and the exact command you used to compile.

c:\fall2007\test\Homework\Due Dec 5> javac WorkerTester.java

The WorkerTester.java file as well as all the other files associated with it is located in the directory, so I don't think I have to specify the classpath as a parameter.

I get the same compile-time error as when I compile the file with Textpad; can't find an HourlyWorker constructor matching the declaration. I've copied your code and it works perfectly. How do you have your files organized?

Like this?
-WorkerDirectory
+ Worker.java
+ HourlyWorker.java
+ SalariedWorker.java
+ WorkerTester.java

Some package definitions lacking maybe?

Black Box

Everything is in the same directory.

edit: hmm..weird. I tried to compile the files on the compiler at school and it works fine.

[satya5321]

hi from my understanding there is no default constructor defined in any of the Classes that you wrote.when you are overloading constructor the default constructor is not provided. externally you have to write the default constructor

tell me i am wrong.

[masijade]

hi from my understanding there is no default constructor defined in any of the Classes that you wrote.when you are overloading constructor the default constructor is not provided. externally you have to write the default constructor

tell me i am wrong.

This has nothing to do with a default constructor. And, you neverhave to implement a default constructor. Only if you want to.

Edit: Well, I shouldn't really say never, but at least the cases where you might have to are not that common, and definately not a problem in this case.

[masijade]

The WorkerTester.java file as well as all the other files associated with it is located in the directory, so I don't think I have to specify the classpath as a parameter.

"." is not necessarily on the classpath, and if it is not, then yes, you do have to add it. So did you actually try with the command I showed you? Or did you just assume that it wouldn't make a difference? Also, try to compile one of the classes that does not depend on any of the others, and then make sure that the classfile actually appears in the same directory as the java file (not that you have some alias set that automatically causes the compiler to place the class files elsewhere). If it is there, then compile them one at a time from the file with the least dependencies, to the file with the most. More than bit annoying, but hey.