icecream.java

Java编程思想 第九课 全源码

//: c09:IceCream.java
// From 'Thinking in Java, 2nd ed.' by Bruce Eckel
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
// Returning arrays from methods.
import java.util.*;

public class IceCream {
  static String[] flav = {
    "Chocolate", "Strawberry",
    "Vanilla Fudge Swirl", "Mint Chip",
    "Mocha Almond Fudge", "Rum Raisin",
    "Praline Cream", "Mud Pie" 
  };
  static String[] flavorSet(int n) {
    // Force it to be positive & within bounds:
    n = Math.abs(n) % (flav.length + 1);
    String[] results = new String[n];
    boolean[] picked = 
      new boolean[flav.length];
    for (int i = 0; i < n; i++) {
      int t;
      do 
        t = (int)(Math.random() * flav.length);
      while (picked[t]);
      results[i] = flav[t];
      picked[t] = true;
    }
    return results;
  }
  public static void main(String[] args) {
    IceCream ic = new IceCream();
    int m=0;
    try{
    if (args.length>1 || args.length == 0){
    	System.out.println(" Usage : "+"IceCream " + "number");	    
    }

    m = Integer.parseInt(args[0]);
  	}catch(Exception e){
  		//System.out.println("" + printStackTrace);  		
  		}
    for(int i = 0; i < m; i++) {
      System.out.println(
        "flavorSet(" + i + ") = ");
      String[] fl = flavorSet(flav.length);
      for(int j = 0; j < fl.length; j++)
        System.out.println("\t" + fl[j]);
    }
}
} ///:~}