java中的数组与集合的排序---摘抄自:http://blog.csdn.net/jonathan_q_bo/archive/2005/11/29/539043.aspx

 /*
 * Created on 2005-11-27
 *
 * TODO To change the template for this generated file go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
package sort;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
//import java.util.Random;
import java.lang.Math;

/**
 * @author Jonathan
 *
 * <b>排序方法汇总</b>
 * TODO To change the template for this generated type comment go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
public class SortCollection{

 private void sortByComparableOfList(){
  ArrayList al = new ArrayList();
  for(int i = 0; i < 10; i++){
   int tmp = (int)(Math.random()*10);
   al.add(new SortedObjectOne(tmp,"List." + i));
  }
  Collections.sort(al);
  Iterator itt = al.iterator();
  while(itt.hasNext())
   System.out.println(itt.next());
 }
 
 private void sortByComparatorOfList(){
  ArrayList al = new ArrayList();
  for(int i = 0; i < 10; i++){
   int tmp = (int)(Math.random()*10);
   al.add(new SortedObjectOne(tmp,"List." + i));
  }
  Collections.sort(al, new SortOrderAsc());
  Iterator itt = al.iterator();
  while(itt.hasNext())
   System.out.println(itt.next());
 }
 
 /**整形数组的默认排序*/
 private void sortByDefaultOfArray(){
  int[] array = new int[10];
  for(int i = 0; i < array.length; i++){
   array[i] = (int)(Math.random()*10);
  }
  Arrays.sort(array);
  for(int i = 0; i < array.length; i++){
   System.out.println("<Array" + i + ">:<" + array[i] + ">");
  }
 }
 
 /**对象数组的默认排序*/
 private void sortByComparableOfArray(){
  SortedObjectOne[] array = new SortedObjectOne[10];
  for(int i = 0; i < array.length; i++){
   array[i] = new SortedObjectOne((int)(Math.random()*10), "Array" + i);
  }
  Arrays.sort(array);
  for(int i = 0; i < array.length; i++){
   System.out.println(array[i]);
  }
 }
 
 /**对象数组的定制排序*/
 private void sortByComparatorOfArray(){
  SortedObjectOne[] array = new SortedObjectOne[10];
  for(int i = 0; i < array.length; i++){
   array[i] = new SortedObjectOne((int)(Math.random()*10), "Array" + i);
  }
  Arrays.sort(array, new SortOrderAsc());
  for(int i = 0; i < array.length; i++){
   System.out.println(array[i]);
  }
 }
 
 public static void main(String args[]){
  SortCollection sc = new SortCollection();
  System.out.println("-- sort list by comparable --");
  sc.sortByComparableOfList();
  System.out.println("-- sort list by comparator --");
  sc.sortByComparatorOfList();
  System.out.println("-- sort array by default --");
  sc.sortByDefaultOfArray();
  System.out.println("-- sort array by comparable --");
  sc.sortByComparableOfArray();
  System.out.println("-- sort array by comparator --");
  sc.sortByComparatorOfArray();
 }
 
}

/** 根据Comparable接口确定排序顺序 */
class SortedObjectOne implements Comparable{
 
 public int attr1;
 public String attr2;
 
 public SortedObjectOne(int attr1,String attr2){
  this.attr1 = attr1;
  this.attr2 = attr2;
 }
 
 /* (non-Javadoc)
  * @see java.lang.Comparable#compareTo(java.lang.Object)
  */
 public int compareTo(Object arg0) {
  // TODO Auto-generated method stub
  if(arg0 instanceof SortedObjectOne){
   SortedObjectOne obj = (SortedObjectOne)arg0;
   return this.attr1 - obj.attr1;
  }
  return 0;
 }
 
 
 /* (non-Javadoc)
  * @see java.lang.Object#toString()
  */
 public String toString() {
  // TODO Auto-generated method stub
  return "<" + this.attr2 + ">:<" + this.attr1 + ">";
 }
}

/** 根据Comparator确定排序顺序 */
class SortOrderAsc implements Comparator{

 /* (non-Javadoc)
  * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
  */
 public int compare(Object arg0, Object arg1) {
  // TODO Auto-generated method stub
  if(arg0 instanceof SortedObjectOne && arg1 instanceof SortedObjectOne){
   SortedObjectOne tmp0 = (SortedObjectOne)arg0;
   SortedObjectOne tmp1 = (SortedObjectOne)arg1;
   return tmp1.attr1 - tmp0.attr1;
  }
  return 0;
 }

}