ELEMENTS OF JAVA PROGRAM

Read file using FileInputStream

import java.io.*;

public class ReadStringFromFile

{ 

public static void main(String[] args)

{

File file = new File("C://FileIO//ReadString.txt");

int ch;

StringBuffer strContent = new StringBuffer("");

FileInputStream fin = null;

try 

 { 

 fin = new FileInputStream(file);

while( (ch = fin.read()) != -1)

strContent.append((char)ch);

fin.close();

}

catch(FileNotFoundException e)

{

System.out.println("File " + file.getAbsolutePath() +

" could not be found on filesystem");

}

catch(IOException ioe)

{

System.out.println("Exception while reading the file" + ioe);

}

System.out.println("File contents :");

System.out.println(strContent);

  }

}

Iterate through elements Java Vector using ListIterator

import java.util.Vector;

import java.util.ListIterator; 

public class IterateThroughVectorUsingListIteratorExample

{

public static void main(String[] args)

{

Vector v = new Vector();

v.add("1");

v.add("2");

v.add("3");

v.add("4");

v.add("5");

ListIterator itr = v.listIterator();

System.out.println("Iterating through Vector elements in forward direction...");

while(itr.hasNext())

System.out.println(itr.next());

System.out.println("Iterating through Vector elements in backward direction...");

while(itr.hasPrevious())

System.out.println(itr.previous());

  }

}

Remove All Items From a List

import java.applet.Applet;

import java.awt.List;

public class RemoveAllItemsFromAList extends Applet

{

public void init()

{

List list = new List(5, true);

list.add("One");

list.add("Two");

list.add("Three");

list.add("Four");

list.add("Five");

list.add("Six");

list.add("Seven");

add(list);

list.removeAll();

  }

}

Swap elements of Java ArrayList

import java.util.ArrayList;

import java.util.Collections;

public class SwapElementsOfArrayListExample

{

 public static void main(String[] args)

{

ArrayList arrayList = new ArrayList();

arrayList.add("A");

arrayList.add("B");

arrayList.add("C");

arrayList.add("D");

arrayList.add("E");

System.out.println("Before swaping, ArrayList contains : " arrayList);

Collections.swap(arrayList,0,4);

System.out.println("After swaping, ArrayList contains : " + arrayList);

   }

}