How to sort an ArrayList of ArrayLists

[vrayudu kumar]

Hello All,

How to sort an ArrayList which contains array of ArrayLists
ArrayList = [
["-1","qaaa","test"],
["-1","qaaa","test123"],
["-1","bbba","test123"],
["-1","qaaa","test123"],
["-1","qaaa","test123"],
["-1","bbba","test123"]]

i want to sort this arraylist based on the second parameter in each arraylist.

How can i solve this.

Thanks in advance.

[Ernest Friedman-Hill]

Use the static sort() method in the java.util.Collections class which takes a List and a Comparator as arguments. You have to write a class which implements Comparator, and in the compare() method, you'll can expect two Lists as arguments. Extract the appropriate entry from each of them, and compare the entries, returning the comparison value. It might look like (this is JDK 1.5, which simplifies things quite a bit

import java.util.List;
import java.util.Comparator;
 
class MyComparator implements Comparator<List<String>> {
  public int compare(List<String> list1, List<String> list2) {
    return list1.get(1).compareTo(list2.get(2));
  }
}

[Gowri Kalyani K V]

what's the way to implement the same in jdk1.4

[Seb Mathe]

You've just to do explicit cast (from list.get(1) to String)

[vrayudu kumar]

I did the casting to String, Its working fine. Thanks seb