Source of ClassIODemo.java


  1: 
  2: import java.io.*;
  3: 
  4: public class ClassIODemo
  5: {
  6:     public static void main(String[] args)
  7:     {
  8:         ObjectOutputStream outputStream = null;
  9: 
 10:         try
 11:         {
 12:             outputStream =
 13:                   new ObjectOutputStream(
 14:                       new FileOutputStream("species.records"));
 15:         }
 16:         catch(IOException e)
 17:         {
 18:             System.out.println(
 19:                      "Error opening file species.records.");
 20:             System.out.println("for writing.");
 21:             System.exit(0);
 22:         }
 23: 
 24:         Species oneRecord =
 25:                     new Species("Calif. Condor", 27, 0.02);
 26:         Species secondRecord =
 27:                     new Species("Black Rhino", 100, 1.0);
 28:         try
 29:         {
 30:             outputStream.writeObject(oneRecord);
 31:             outputStream.writeObject(secondRecord);
 32:             outputStream.close( );
 33:         }
 34:         catch(IOException e)
 35:         {
 36:             System.out.println(
 37:                      "Error writing to file species.records.");
 38:             System.exit(0);
 39:         }
 40: 
 41:         System.out.println(
 42:                    "Records sent to file species.record.");
 43:         System.out.println(
 44:               "Now let's reopen the file and echo the records.");
 45:         ObjectInputStream inputStream = null;
 46: 
 47:         try
 48:         {
 49:             inputStream =
 50:                  new ObjectInputStream(
 51:                       new FileInputStream("species.records"));
 52:         }
 53:         catch(IOException e)
 54:         {
 55:             System.out.println(
 56:                      "Error opening file species.records.");
 57:             System.out.println("for reading.");
 58:             System.exit(0);
 59:         }
 60: 
 61:         Species readOne = null, readTwo = null;
 62: 
 63:         try
 64:         {
 65:             readOne = (Species)inputStream.readObject( );
 66:             readTwo = (Species)inputStream.readObject( );
 67:             inputStream.close( );
 68:        }
 69:         catch(Exception e)
 70:         {
 71:             System.out.println(
 72:                      "Error reading from file species.records.");
 73:             System.exit(0);
 74:         }
 75:         System.out.println("The following were read\n"
 76:                          + "from the file species.record:");
 77:         System.out.println(readOne);
 78:         System.out.println( );
 79:         System.out.println(readTwo);
 80:         System.out.println("End of program.");
 81:     }
 82: }