goldexploration.java

Java经典例程 从外国一大学计算机教授出版物下载的代码 经典

import java.io.*;
import javagently.*;
import myutilities.*;

class GoldExploration {

  /* The Gold class     by J M Bishop  Jan 1997
   *                    Java 1.1 October 1997
   * Transforms raw geological readings into a character map of a
   * possible gold reef.
   * Illustrates two different multi-dimensional arrays in a class.
   */

  int rowMax = 8;
  int colMax = 8;
  char   map [][]  = new char[rowMax][colMax];
  double data [][] = new double[rowMax][colMax];
  char blank = ' ';
  char cover = '*';

  Stream fin;

  GoldExploration () throws IOException{
    introduction();
    getData();
    assess();
    report();
  }

  public void getData() throws IOException {
    for (int i = 0; i < rowMax; i++)
      for (int j = 0; j < colMax; j++)
        data[i][j] = fin.readDouble();
  }

  public void assess() {
    double point, average;
    for (int i = 0; i < rowMax; i++) {
      for (int j = 0; j < colMax; j++) {
        map[i][j] = blank;
        }
      }
      for (int i = 1; i < rowMax-1; i++) {
        for (int j = 1; j < colMax-1; j++) {
          point = data[i][j];
          average = (data[i-1][j] + data[i+1][j] +
                    data[i][j-1] + data[i][j+1]) / 4;
          if (point > average)
              map[i][j] = cover;
          }
        }
  }

  public void report() {
    System.out.println("Map of possible boundaries of the " +
			        "gold reef");
    System.out.println("===================================" +
				  "========");
    System.out.println();
    System.out.print("  ");
    for (int j = 0; j < colMax; j++) {
      System.out.print(j+" ");
    }
    System.out.println();
    for (int i = 0; i < rowMax; i++) {
      System.out.print(i+" ");
      for (int j = 0; j < colMax; j++)
        System.out.print(map[i][j]+" ");
      System.out.println();
    }
    System.out.println("Good luck prospecting!");
  }

  void introduction () throws IOException {
    System.out.println("******* Savanna Exploration Inc. *****");
    System.out.println("Will use test data in gold.dat"+
                       " if file open is unsuccessful");
    fin = Filer.open("");
    System.out.println("We shall find gold!\n");
  }

  public static void main(String[] args) throws IOException {
    new GoldExploration ();
  }

}