Implement the Java.util.Comparator interface and sort the collection of objects in multiple combinations of attributes

Commons-beanutils provides a number of features, one of which is useful for sorting object collections, such as Collections.sort (peoples, New Beancomparator ("Age"));

In addition, you can use the Java.util.Collections sort method to sort the collection collection, including multi-column combination sorting, which is an example of customizing the object property Collation yourself Java.util.Comparator:

Package com.lph.test;

import java.util.Comparator;

import java.util.Iterator;

import java.util.List;

import java.util.LinkedList;

/**
*
* Custom Object Multi-attribute (multi-column) combination sorting
* <p>title:is a class</p>
*
* <p>description: Class </p>
*
* <p>copyright:copyright (c) 2006</p>
*
* <p>Company:sunrise</p>
*
* @author Islph
* @version 1.0
*/
Public class Compositecomparator implements Comparator {

/** in the Condition list, comparators ' priority decrease from head to tail */

Private List comparators = new linkedlist ();

/** get the comparators, you can manipulate it as need. */

Public List getcomparators () {

return comparators;

}

/** add a batch of comparators to the condition list */

Public void addcomparators (comparator[] comparatorarray) {

if (Comparatorarray = = null) {

return;

}

for (int i = 0; i < comparatorarray.length; i++) {

Comparators.add (Comparatorarray[i]);

}

}

/** compare by the priority */

Public int Compare (object O1, Object O2) {

for (Iterator Iterator = Comparators.iterator (); Iterator.hasnext ();) {

Comparator Comparator = (Comparator) iterator.next ();

int result = Comparator.compare (O1, O2);

if (Result! = 0) {

return result;

}

}

return 0;

}

}

Sort by attribute County_no town, ddp_id terminal combination

Compositecomparator mycomparator = new compositecomparator ();

Mycomparator.addcomparators (

New Comparator[] {

New Comparator () {

Public int Compare (object A, object B) {

DisplayForm Aobj, Bobj;

Aobj = (displayform) A;

Bobj = (displayform) b;

String aStr = (string) aobj.get ("County_no");

String bStr = (string) bobj.get ("County_no");

return Astr.compareto (BSTR);

}

}

, new Comparator () {

Public int Compare (object A, object B) {

DisplayForm Aobj, Bobj;

Aobj = (displayform) A;

Bobj = (displayform) b;

String aStr = (string) aobj.get ("ddp_id");

String bStr = (string) bobj.get ("ddp_id");

return Astr.compareto (BSTR);

}

}

});

Java.util.Collections.sort (Listresult, mycomparator);

Implement the Java.util.Comparator interface and sort the collection of objects in multiple combinations of attributes