Apache Commons Collections Collectionutils Tool class simple to use

Collectionutils provides many ways to manipulate collections , and the common methods are as follows

import org.apache.commons.collections.collectionutils;import java.util.arraylist;import  java.util.list;public class collectionutilstest {     public  Static void main (String[] args)  {        List< Integer> a = new arraylist<integer> ();         List<Integer> b = null;        List< Integer> c = new arraylist<integer> ();         c.add (5);         c.add (6);         //determines whether the collection is empty         system.out.println ( Collectionutils.isempty (a));   //true         System.out.println (Collectionutils.isempty (b)); &NBSP;&NBSP;&NBsp;//true        system.out.println (CollectionUtils.isEmpty (c));    //false        //determines whether the collection is not empty          system.out.println (Collectionutils.isnotempty (a));   //false         system.out.println (Collectionutils.isnotempty (b));    False        system.out.println (Collectionutils.isnotempty (c));    //true        //operation between two sets          List<Integer> e = new ArrayList<Integer> ();         e.add (2);         e.add (1);         List<Integer> f = new ArrayList< Integer> ();     &Nbsp;   f.add (1);         f.add (2);         List<Integer> g = new ArrayList<Integer> ();         g.add (        //); Compare two set-valued         system.out.println (Collectionutils.isequalcollection (e,f ));    //true        system.out.println ( Collectionutils.isequalcollection (f,g));   //false         List<Integer> h = new ArrayList<Integer> ();         h.add (1);         h.add (2);         h.add (3);;         List<Integer> i = new ArrayList< Integer> ();         i.add (3);         i.add (3);         i.add (4);         i.add (5);         //         system.out.println (Collectionutils.union (i,h));   //[1, 2, 3, 3, 4,  5]        //intersection          System.out.println (Collectionutils.intersection (i,h)); //[3]        The complement of the  //intersection         system.out.println (collectionutils.disjunction (i, h));  //[1, 2, 3, 4, 5]        //e and H difference          system.out.println (Collectionutils.subtract (h,i));  //[1, 2 ]    &Nbsp;   system.out.println (Collectionutils.subtract (i,h)); //[3, 4, 5]     }}

Apache Commons Collections Collectionutils Tool class simple to use