testiterated.java

JAVA 2入门经典 练习答案

// Chapter 7 Exercise 4

// *** marks new or changed code from previous exercise

public class TestIterated {
  public static void main(String args[]) {
    int iteration = 0;  	// Store the iteration number.                           // ***
    try {
      loopy();          	// Call the method that will throw the exception.
    }

    catch(IteratedArithmeticException e) {
      System.out.println(e);
      iteration = e.getIteration();                                                // ***
    }

    finally {                                                                      // ***
      System.out.println("Arithmetic exception occurred at iteration "+iteration); // ***
    }                                                                              // ***
  }

  // This method throws an exception - eventually:
  static void loopy() throws IteratedArithmeticException {
    int iteration;               // Iteration counter
    int result;                  // Stores a result
    int divisor;                 // Random divisor

    // Loop will continue until an exception is thrown:
    for(iteration=0;;iteration++)
      try {
        divisor = (int)(100*Math.random());     // Generate a random divisor.
        result = 1000/divisor;                  // If we hit zero - bingo!		
      }

      catch(ArithmeticException e) {
        throw new IteratedArithmeticException(iteration);
      }
  }
}