Questions and Exercises

Questions

1. Is the following code legal?

   try {
       
   } finally {
       
   }
   

2. What exception types can be caught by the following handler?

   catch (Exception e) {
        
   }
   

   What is wrong with using this type of exception handler?

3. Is there anything wrong with the following exception handler as written? Will this code compile?

   try {
   
   } catch (Exception e) {
       
   } catch (ArithmeticException a) {
       
   }
   

4. Match each situation in the first list with an item in the second list.
   1. int[] A;
A[0] = 0;
   2. The JVM starts running your program, but the JVM can't find the Java platform classes. (The Java platform classes reside in classes.zip or rt.jar.)
   3. A program is reading a stream and reaches the end of stream marker.
   4. Before closing the stream and after reaching the end of stream marker, a program tries to read the stream again.
   1. __error
   2. __checked exception
   3. __compile error
   4. __no exception

   Exercises

   1. Add a readList method to ListOfNumbers.java. This method should read in int values from a file, print each value, and append them to the end of the vector. You should catch all appropriate errors. You will also need a text file containing numbers to read in.

   2. Modify the following cat method so that it will compile.

      public static void cat(File file) {
          RandomAccessFile input = null;
          String line = null;
      
          try {
              input = new RandomAccessFile(file, "r");
              while ((line = input.readLine()) != null) {
                  System.out.println(line);
              }
              return;
          } finally {
              if (input != null) {
                  input.close();
              }
          }
      }
      

   Check your answers.