collections---------------treeset----------------comparator

import java.util.*;
class MyComparator implements Comparator
{
    public int compare(Object obj1,Object obj2)
    {
        Integer i1=(Integer) obj1;
        Integer i2=(Integer) obj2;
        //return i1.compareTo(i2);//Ascending Order
        //return -i1.compareTo(i2);//Dscending Order
        //return +1;//INSERTION ORDER
        return -1;//REVERSE INSERTION ORDER
       
    }
}
class  CustomTreeSetDemo//follows dictionary order but we can customize using comparatot interface.
{
    public static void main(String[] args)
    {
        TreeSet ts=new TreeSet(new MyComparator());
        ts.add(10);//doesn't follwo insertion order
        ts.add(20);
        ts.add(50);
        ts.add(20);//don't allows duplicate values
        ts.add(40);
        ts.add(30);
        ts.add(70);
       
        ts.add(60);
       

        System.out.println(ts.add(20));//false
        //System.out.println(ts.add(null));//allow one time get R.E. i.e. Exception in thread "main" java.lang.NullPointerExceptio
       

        //ts.add("a");//hetero geneous objects are allowed.
        //R.E. i.e. Exception in thread "main" java.lang.ClassCastException: java.lang.Integer canno
        //t be cast to java.lang.String
        //at java.lang.String.compareTo(Unknown Source)
        //at java.util.TreeMap.put(Unknown Source)
        //at java.util.TreeSet.add(Unknown Source)
       //at TreeSetDemo.main(TreeSetDemo.java:20)
       
        System.out.println(ts);
    }
}

collections-------Set----------------TreeSet

import java.util.*;
class  TreeSetDemo
{
    public static void main(String[] args)
    {
        TreeSet ts=new TreeSet();
        ts.add(10);//doesn't follwo insertion order
        ts.add(20);
        ts.add(20);//don't allows duplicate values
        ts.add(30);
        ts.add(40);
        ts.add(50);
        ts.add(60);
        ts.add(70);

        System.out.println(ts.add(20));//false
        //System.out.println(ts.add(null));//allow one time get R.E. i.e. Exception in thread "main" java.lang.NullPointerExceptio
       

        //ts.add("a");//hetero geneous objects are allowed.
        //R.E. i.e. Exception in thread "main" java.lang.ClassCastException: java.lang.Integer canno
        //t be cast to java.lang.String
        //at java.lang.String.compareTo(Unknown Source)
        //at java.util.TreeMap.put(Unknown Source)
        //at java.util.TreeSet.add(Unknown Source)
       //at TreeSetDemo.main(TreeSetDemo.java:20)
       
        System.out.println(ts);
    }
}

Collection-----------Set----------HashSet

import java.util.*;
class  HashSetDemo
{
    public static void main(String[] args)
    {
        HashSet ts=new HashSet();
        ts.add(10);//doesn't follow insertion order
        ts.add(20);
        ts.add(20);//don't allows duplicate values

        System.out.println(ts.add(20));//false
        System.out.println(ts.add(null));//allow one time retuns true
        System.out.println(ts.add(null));//false

        ts.add("a");//hetero geneous objects are allowed.
        ts.add("b");
        ts.add("c");
        System.out.println(ts);
    }
}

Collections----------->>>>>>>>>Stack

Stack:[LAST IN FIRST OUT]

import java.util.Stack;
class StackExamp
{
public static void main(String[] args)
{Stack s=new Stack();
s.push("a");
s.push("b");
s.push("c");
s.push("d");
s.push("e");
System.out.println(s);
s.pop();
System.out.println(s);
System.out.println(s.peek());
System.out.println(s.size());
System.out.println(s.search("b"));// returns the position of b i.e.3
System.out.println(s.search("z"));//-1
ArrayList al=new ArrayList(s);// convertion  object  stack to arraylist
System.out.println(al);



}
}


OUTPUT:
D:\anvesh_java>java StackExamp
[a, b, c, d, e]
[a, b, c, d]
d
4
3
-1

collections-------------->>>>>>>>>>>Linkedlist

LinkedList;   It is best for Insrtion and deletion operations

LL is Given by java.util.LinkedList Package.
programe;
import java.util.LinkedList;
class LnkdListExamp
{
public static void main(String[] args)
{LinkedList ll=new LinkedList();
ll.add("c");
ll.add("c");
ll.add("c");
ll.add("c");
ll.add("c");
System.out.println(ll);
ll.addFirst("f");
ll.addLast("l");
System.out.println(ll);

System.out.println(ll.getFirst());
System.out.println(ll.getLast());

}
}
output:
D:\anvesh_java>java LnkdListExamp
[c, c, c, c, c]
[f, c, c, c, c, c, l]
f
l





D:\anvesh_java>javap java.util.LinkedList
Compiled from "LinkedList.java"
public class java.util.LinkedList extends java.util.AbstractSequentialList imple
ments java.util.List,java.util.Deque,java.lang.Cloneable,java.io.Serializable{
    public java.util.LinkedList();
    public java.util.LinkedList(java.util.Collection);
    public java.lang.Object getFirst();
    public java.lang.Object getLast();
    public java.lang.Object removeFirst();
    public java.lang.Object removeLast();
    public void addFirst(java.lang.Object);
    public void addLast(java.lang.Object);
    public boolean contains(java.lang.Object);
    public int size();
    public boolean add(java.lang.Object);
    public boolean remove(java.lang.Object);
    public boolean addAll(java.util.Collection);
    public boolean addAll(int, java.util.Collection);
    public void clear();
    public java.lang.Object get(int);
    public java.lang.Object set(int, java.lang.Object);
    public void add(int, java.lang.Object);
    public java.lang.Object remove(int);
    public int indexOf(java.lang.Object);
    public int lastIndexOf(java.lang.Object);
    public java.lang.Object peek();
    public java.lang.Object element();
    public java.lang.Object poll();
    public java.lang.Object remove();
    public boolean offer(java.lang.Object);
    public boolean offerFirst(java.lang.Object);
    public boolean offerLast(java.lang.Object);
    public java.lang.Object peekFirst();
    public java.lang.Object peekLast();
    public java.lang.Object pollFirst();
    public java.lang.Object pollLast();
    public void push(java.lang.Object);
    public java.lang.Object pop();
    public boolean removeFirstOccurrence(java.lang.Object);
    public boolean removeLastOccurrence(java.lang.Object);
    public java.util.ListIterator listIterator(int);
    public java.util.Iterator descendingIterator();
    public java.lang.Object clone();
    public java.lang.Object[] toArray();
    public java.lang.Object[] toArray(java.lang.Object[]);
    static java.util.LinkedList$Entry access$000(java.util.LinkedList);
    static int access$100(java.util.LinkedList);
    static java.lang.Object access$200(java.util.LinkedList, java.util.LinkedLis
t$Entry);
    static java.util.LinkedList$Entry access$300(java.util.LinkedList, java.lang
.Object, java.util.LinkedList$Entry);
}


D:\anvesh_java>

collections---------->>>>>>>>>>>>Vectro Class----------------->>>>>>>>>>>Synchronized Methods

D:\anvesh_java>javap java.util.Vector
Compiled from "Vector.java"
public class java.util.Vector extends java.util.AbstractList implements java
l.List,java.util.RandomAccess,java.lang.Cloneable,java.io.Serializable{
    protected java.lang.Object[] elementData;
    protected int elementCount;
    protected int capacityIncrement;
    public java.util.Vector(int, int);
    public java.util.Vector(int);
    public java.util.Vector();
    public java.util.Vector(java.util.Collection);
    public synchronized void copyInto(java.lang.Object[]);
    public synchronized void trimToSize();
    public synchronized void ensureCapacity(int);
    public synchronized void setSize(int);
    public synchronized int capacity();
    public synchronized int size();
    public synchronized boolean isEmpty();
    public java.util.Enumeration elements();
    public boolean contains(java.lang.Object);
    public int indexOf(java.lang.Object);
    public synchronized int indexOf(java.lang.Object, int);
    public synchronized int lastIndexOf(java.lang.Object);
    public synchronized int lastIndexOf(java.lang.Object, int);
    public synchronized java.lang.Object elementAt(int);
    public synchronized java.lang.Object firstElement();
    public synchronized java.lang.Object lastElement();
    public synchronized void setElementAt(java.lang.Object, int);
    public synchronized void removeElementAt(int);
    public synchronized void insertElementAt(java.lang.Object, int);
    public synchronized void addElement(java.lang.Object);
    public synchronized boolean removeElement(java.lang.Object);
    public synchronized void removeAllElements();
    public synchronized java.lang.Object clone();
    public synchronized java.lang.Object[] toArray();
    public synchronized java.lang.Object[] toArray(java.lang.Object[]);
    public synchronized java.lang.Object get(int);
    public synchronized java.lang.Object set(int, java.lang.Object);
    public synchronized boolean add(java.lang.Object);
    public boolean remove(java.lang.Object);
    public void add(int, java.lang.Object);
    public synchronized java.lang.Object remove(int);
    public void clear();
    public synchronized boolean containsAll(java.util.Collection);
    public synchronized boolean addAll(java.util.Collection);
    public synchronized boolean removeAll(java.util.Collection);
    public synchronized boolean retainAll(java.util.Collection);
    public synchronized boolean addAll(int, java.util.Collection);
    public synchronized boolean equals(java.lang.Object);
    public synchronized int hashCode();
    public synchronized java.lang.String toString();
    public synchronized java.util.List subList(int, int);
    protected synchronized void removeRange(int, int);
}

Programme;
import java.util.Vector;
class VectorExamp
{
public static void main(String[] args)
{Vector v=new Vector();
v.addElement("a");
v.addElement("b");
v.addElement("c");
v.addElement("d");
v.addElement("d");
System.out.println(v);
v.removeElement("d");
System.out.println(v);System.out.println(v.size());
}
}

out put:

D:\anvesh_java>java VectorExamp
[a, b, c, d, d]
[a, b, c, d]
4

D:\anvesh_java>

Array List Method------------->>>>>>>>>>>clone()

import java.util.GregorianCalendar;

public class ObjectDemo {

   public static void main(String[] args) {

      GregorianCalendar calendar = new GregorianCalendar();

     
      GregorianCalendar  y = (GregorianCalendar) calendar.clone();

   
      System.out.println("" + calendar.getTime());
      System.out.println("" + y.getTime());


   }
}