testdata.java

Java 程序设计教程（第五版）EXAMPLESchap10源码

//********************************************************************
//  TestData.java       Author: Lewis/Loftus
//
//  Demonstrates I/O exceptions and the use of a character file
//  output stream.
//********************************************************************

import java.util.Random;
import java.io.*;

public class TestData
{
   //-----------------------------------------------------------------
   //  Creates a file of test data that consists of ten lines each
   //  containing ten integer values in the range 10 to 99.
   //-----------------------------------------------------------------
   public static void main (String[] args) throws IOException
   {
      final int MAX = 10;

      int value;
      String file = "test.dat";

      Random rand = new Random();

      FileWriter fw = new FileWriter (file);
      BufferedWriter bw = new BufferedWriter (fw);
      PrintWriter outFile = new PrintWriter (bw);

      for (int line=1; line <= MAX; line++)
      {
         for (int num=1; num <= MAX; num++)
         {
            value = rand.nextInt (90) + 10;
            outFile.print (value + "   ");
         }
         outFile.println ();
      }

      outFile.close();
      System.out.println ("Output file has been created: " + file);
   }
}