chart.java

Java学习源代码检索系统免费版

//==============================================================
// Chart.java - Sample data object with Comparator implementation
//
// Java学习源代码检索系统 Ver 1.0 20031015 免费正式版
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//==============================================================

import java.util.Comparator;

public class Chart implements Comparable {
// Constants
 final static int BYNUMBER = 1;
 final static int BYNAME = 2;
 final static int BYSCALE = 3;

 public int number;
 public String name;
 public long scale;
 public Chart(int number, String name, long scale) {
  this.number = number;
  this.name = name;
  this.scale = scale;
 }
 public int compareTo(Object o) {
  Chart other = (Chart)o;
  return name.compareTo(other.name);
 }
 public String toString() {
  return number + "  " + name + "  1:" + scale;
 }

// Comparator "factory" methods
 public static final Comparator byNumber() {
  return new ChartComparator(BYNUMBER);
 }
 public static final Comparator byName() {
  return new ChartComparator(BYNAME);
 }
 public static final Comparator byScale() {
  return new ChartComparator(BYSCALE);
 }

// Private inner Comparator class
 private static class ChartComparator implements Comparator {

  private int compType;  // Type of comparison to perform

  // Constructor saves comparison type identifier
  ChartComparator(int compType) {
   this.compType = compType;  // BYNUMBER, BYNAME, or BYSCALE
  }

  // Implement the Comparator interface's method
  public int compare(Object o1, Object o2) {
   Chart c1 = (Chart)o1;  // Type cast objects to Charts
   Chart c2 = (Chart)o2;
   switch (compType) {
    case BYNUMBER:
     return (c1.number < c2.number ? -1 : 
      (c1.number == c2.number ? 0 : 1));
    case BYNAME:
     return c1.name.compareTo(c2.name);
    case BYSCALE:
     return (c1.scale < c2.scale ? -1 : 
      (c1.scale == c2.scale ? 0 : 1));
    default:
     return 0;  // Satisfy compiler; can't happen
   }
  }
 } // private inner class
} // Chart class