Programming Tutorials

Use List, Set, SortedSet, LinkedHashSet, Map, LinkedHashMap in java

By: Saravanan Printer Friendly Format    

In this tutorial we can see how to use Collections in java program. Now we can see uses of List, Set, SortedSet, LinkedHashSet, Map, LinkedHashMap.

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;

public class CollectionExample 
 {
  public static void main(String[] args) 
   {
    List l = new LinkedList();
    l.add("List:angel");
    l.add("schildt");
    l.add("mathew");
    l.add("schildt");
    print(l); 
  
    Set s = new HashSet();
    s.add("set:rose");
    s.add("schildt");
    s.add("mathew");
    s.add("schildt");
    print(s); 

    SortedSet ss = new TreeSet();
    ss.add("set:jasmine");
    ss.add("schildt");
    ss.add("mathew");
    ss.add("schildt");
    print(ss); 

    LinkedHashSet sss = new LinkedHashSet();
    sss.add("set:winslet");
    sss.add("schildt");
    sss.add("mathew");
    sss.add("schildt");
    print(sss); 

    Map m1 = new HashMap();
    m1.put("map", "HashMap");
    m1.put("schildt", "java2");
    m1.put("mathew", "Hyden");
    m1.put("schildt", "java2s");
    print(m1.keySet()); 
    print(m1.values()); 

    SortedMap sm = new TreeMap();
    sm.put("map", "TreeMap");
    sm.put("schildt", "java2");
    sm.put("mathew", "Hyden");
    sm.put("schildt", "java2s");
    print(sm.keySet()); 
    print(sm.values());
 
    LinkedHashMap lm = new LinkedHashMap();
    lm .put("map", "LinkedHashMap");
    lm .put("schildt", "java2");
    lm .put("mathew", "Hyden");
    lm .put("schildt", "java2s");
    print(lm .keySet()); 
    print(lm .values()); 
  }

  static void print(Collection coll) 
  {
    Iterator iter = coll.iterator();
    while (iter.hasNext()) 
    {
      String elem = (String) iter.next();
      System.out.print(elem + " ");
    }
    System.out.println();
  }

}

Output:

List:angel schildt mathew schildt
set:rose schildt mathew
schildt set:jasmine mathew
set:winslet schildt mathew
schildt mathew map
java2 Hyden HashMap
schildt mathew map
java2 Hyden TreeMap
map schildt mathew
LinkedHashMap java2 Hyden