Java Collection Pro

Iterate Over Unmodifiable Collection

import java.util.ArrayList;

import java.util.Collection;

import java.util.Collections;

import java.util.Iterator;

import java.util.List;

public class UnmodifiableCollection

{

public static void main(String args[])

{

List list = new ArrayList();

list.add("This");

list.add("is");

list.add("Unmodifiable Collection");

System.out.println("Element added to list: " + list.get(2));

Collection immutableCol = Collections.unmodifiableCollection(list);

Iterator iterator = immutableCol.iterator();

while(iterator.hasNext())

{

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

    }

  }

}

Iterate through the values of Java Tree Map

import java.util.Collection;

import java.util.TreeMap;

import java.util.Iterator;

public class IterateValuesOfTreeMapExample

{

public static void main(String[] args)

{

TreeMap treeMap = new TreeMap();

treeMap.put("1","One");

treeMap.put("2","Two");

treeMap.put("3","Three");

Collection c = treeMap.values();  Iterator itr = c.iterator();

while(itr.hasNext())

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

  }

}

Iterate through the values of Java HashMap

import java.util.Collection;

import java.util.HashMap;

import java.util.Iterator;

public class IterateValuesOfHashMapExample

{

public static void main(String[] args)

{

HashMap hMap = new HashMap();

hMap.put("1","One");

hMap.put("2","Two");

hMap.put("3","Three");

Collection c = hMap.values(); Iterator itr = c.iterator();

while(itr.hasNext())

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

  }

}

Checked and unchecked exceptions in java

import java.io.*;

class Example 

{  

 public static void main(String args[]) 

{

   FileInputStream fis = null;

             fis = new FileInputStream("B:/myfile.txt"); 

   int k; 

            while(( k = fis.read() ) != -1) 

   { 

               System.out.print((char)k); 

   } 

   fis.close();        

   }

}