// Demonstration of the try-catch-finally exception handling mechanism.
//
// Written: 1/19/06

import java.io.*;

public class UsingExceptions1 {

   public static void main( String args[] )
   {
      System.out.println ("Calling throwsException 0");
      try { 
         throwException(0); // call method throwException
      }

      // catch Exceptions thrown by method throwException
      catch ( Exception exception ) {
         System.err.println( "Exception handled in main" );
      }

      System.out.println ();
      System.out.println ("Calling throwsException 1");
      try { 
         throwException(1); // call method throwException
      }

      // catch Exceptions thrown by method throwException
      catch ( Exception exception ) {
         System.err.println( "Exception handled in main" );
      }

      System.out.println ();
      System.out.println ("Calling throwsException2");
      try { 
         throwException(2); // call method throwException
      }

      // catch Exceptions thrown by method throwException
      catch ( Exception exception ) {
         System.err.println( "Exception handled in main" );
      }

   }

   // demonstrate try/catch/finally
   public static void throwException(int n) throws Exception
   {
      // throw an exception and immediately catch it
      try { 
         System.out.println( "Method throwException 1 with parameter " + n );
         if (n == 0)
             throw new Exception();  // generate exception
         if (n == 1)
             throw new IOException();
         System.out.println( "Method throwException 2" );
         
      }

      // catch exception thrown in try block
      catch ( IOException exception ) {
         System.err.println(
            "IOException handled in method throwException" );
      }
      catch ( Exception exception ) {
         System.err.println(
            "Exception handled in method throwException" );
      }

      // this block executes regardless of what occurs in try/catch
      finally {
         System.err.println( "Finally executed in throwException" );
      }

      System.err.println( "End of method throwException" );

   } // end method throwException

} // end class UsingExceptions