Simple Program to sort Arraylist in Ascending and Descending order. U can also sort String,Float,Double.. etc in ArrayList.
ArrayList can be sorted using inbuilt java 1.5 class method Collections.sort(..).
Here is code, save it as file :     Sorting.java
import java.util.*;
public class  Sorting
{
 public static void main(String[] args) 
 {
  //Initilize ArrayList
  ArrayList<Integer> arrayList = new ArrayList<Integer>();//also it can sort String,Float,Double.. etc
  //creating Random numbers
  //Random is a inbuilt java class in 1.5 in util package 
  Random random = new Random();
  //putting Values
  for(int i=1;i<=10;i++)
  {
   int temp = random.nextInt(100);//get random int values between 0 and 100
   arrayList.add(temp);
  }
  //Sorting ArrayList
  System.out.println("Before Sorting..");
  System.out.println(arrayList);
  Collections.sort(arrayList);//Sorting using sort method, default ascending sort
  System.out.println("After Sorting Ascending..");
  System.out.println(arrayList);
  //useing Comparator to sort in descending order 
  Comparator<Integer> comparator = Collections.reverseOrder();
  Collections.sort(arrayList,comparator);//Descending sorting using sort method
  System.out.println("After Sorting Descending..");
  System.out.println(arrayList);
 }
}
 
 
