STUDENT DATA:

• NAME: __________________________________

• ID#: _____________________________________

• SECTION#: ________________________________

1. (20 points):

Fill in the blanks in each of the following:

• Operator ________________ determines whether its first operand is an instance of its second operand.
• In order to support java.lang.Object.clone() method, an object should implement ________________ interface.
• The ________________ class is the top of the class hierarchy. All classes are descendants from this class and inherit methods from it.
• A class member that is not declared as ________________ is implicitly an instance member.
• You can prevent a class from being subclassed by using the ________________ keyword.

2. (20 points):

The following program contains several bugs. Please find and fix them.

    public class SomethingIsWrong {
	public interface anInterface {
	    void aMethod(int aValue) { System.out.println("Hi Mom"); }
	}
	public static void main(String[] args) {
	    StringBuffer[] stringBuffers = new StringBuffer[10];
	    for (int i = 0; i < stringBuffers.length; i++) {
		stringBuffers[i].append("String Buffer at index " + i);
	    }
	}
    }

Please write your answer on the other side of page 1 --->

3. (20 points):

Answer the following questions:

• What is the value of the following expression and why?

  	new Integer(1).equals(new Long(1))

• Is the following code legal?

  	try {
  	    // do something
  	} finally {
  	    // do something
  	}
  	

• What is wrong with using the following type of exception handler?

  	catch (Exception e) {
  	    // do something
  	}
  	

• What is the value of i after the following code snippet executes?

  	int i = 17; i >>= 2; i = i++%5;

Answers:

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4. (20 points):

Suppose that you have written a time server, which periodically notifies its clients of the current date and time. Write an interface that the server could use to enforce a particular protocol on its clients. Please write your answer on the other side of page 2 --->

5. (20 points):

Create a program that reads an unspecified number of integer arguments from the command line and adds them together. For example, suppose that you enter the following:

    java Adder 1 3 2 10 

The program should display 16 and exit. In addition, your program should catch and handle all exceptions that might arise because of a bad input. Each type of exception should be handled independently, by printing an appropriate error message which would specify what exactly was wrong with the input. Hint: to convert a string representing an integral number into an integer, you can use method

    public static int java.lang.Integer.parseInt(String s)
	    throws NumberFormatException 

Good Luck !