JAVA NEW PROGRAMMES

String Buffer Trim

public class JavaStringBufferTrimExample

{

public static void main(String[] args)

{

 StringBuffer sbf = new StringBuffer("   Hello World  !  ");

 String str = sbf.toString().trim();

System.out.println("StringBuffer trim: \"" + str +"\"");

System.out.println("\"" + trim(sbf) + "\"");

}

private static String trim(StringBuffer sbf)

{

int start, end;

for(start = 0; start < sbf.length(); start++)

{

if(sbf.charAt(start) != ' ')

break;

}

for(end = sbf.length(); end > start ; end--)

{

if(sbf.charAt(end-1) != ' ')

break;

}

return sbf.substring(start, end);

    }

}

   

Java Convert int Array To String

import java.util.Arrays;

public class ConvertIntArrayToStringExample

{

public static void main(String args[])

{

int[] intNumbers = new int[]{1, 2, 3, 4,5};

StringBuffer sbfNumbers = new StringBuffer();

String strSeparator = " ";

if(intNumbers.length > 0){

sbfNumbers.append(intNumbers[0]);

 for(int i=1; i < intNumbers.length; i++)

{

sbfNumbers.append(strSeparator).append(intNumbers[i]);

}

}

System.out.println("int array converted to String using for loop");

System.out.println(sbfNumbers.toString());

String strNumbers = Arrays.toString(intNumbers);

System.out.println("String generated from Arrays.toString method: " + strNumbers);

 strNumbers = strNumbers.replaceAll(", ", strSeparator).replace("[", "").replace("]", "");

System.out.println("Final String: " + strNumbers);

  }

}

Java Reverse String Array

import java.util.Collections;

import java.util.List;

import java.util.Arrays;   

public class ReverseStringArrayExample

{

public static void main(String args[])

{

String[] strDays = new String[]{"Sunday", "Monday", "Tuesday", "Wednesday"};

List list = Arrays.asList(strDays);

Collections.reverse(list);  strDays = (String[]) list.toArray();

System.out.println("String array reversed");

for(int i=0; i < strDays.length; i++)

{

System.out.println(strDays[i]);

       }

    }

}

String Buffer To byte Array

public class StringBufferToByteArrayExample

{

 public static void main(String[] args)

{           

StringBuffer sbf = new StringBuffer("Java StringBuffer To byte array example");

 byte bytes[] = sbf.toString().getBytes();

 System.out.println("StringBuffer converted to byte array");

   }

}

String Buffer To File

import java.io.BufferedWriter;

import java.io.File;

import java.io.FileWriter;

import java.io.IOException;

public class JavaStringBufferToFileExample

{

 public static void main(String[] args) throws IOException

{

StringBuffer

sbf = new StringBuffer();

sbf.append("StringBuffer contents first line."); sbf.append(System.getProperty("line.separator"));sbf.append("StringBuffer contents second line.");

BufferedWriter bwr = new BufferedWriter(new FileWriter(new File("d:/demo.txt")));

bwr.write(sbf.toString());

bwr.flush();

bwr.close();

System.out.println("Content of StringBuffer written to File.");

   }

}

Convert Byte object to String object

public class ByteToStringExample

{

public static void main(String[] args)

{

Byte bObj = new Byte("10");

String str = bObj.toString();

System.out.println("Byte converted to String as " + str);

    }

}

Display Day of Week using Java Calendar

import java.util.Calendar;

public class DisplayDayOfWeek

{

public static void main(String[] args)

 {

 Calendar now = Calendar.getInstance();

System.out.println("Current date : " + (now.get(Calendar.MONTH) + 1)

+ "-"

+ now.get(Calendar.DATE)

+ "-"

+ now.get(Calendar.YEAR));

String[] strDays = new String[]

{

"Sunday",

"Monday",

"Tuesday",

"Wednesday",

"Thusday",

"Friday",

"Saturday"

};

System.out.println("Current day is : " +

strDays[now.get(Calendar.DAY_OF_WEEK) - 1]);

   

     }

  }

Disable Button

import java.applet.Applet;

import java.awt.Button;

public class DisableButtonExample extends Applet

{

public void init()

{

Button Button1 = new Button("Ok");

Button Button2 = new Button("Cancel");

add(Button1);

add(Button2);

Button2.setEnabled(false);

    }

}

Java String Buffer setLength

public class JavaStringBufferSetLengthExample

{

public static void main(String[] args)

{

StringBuffer sbf = new StringBuffer("StringBuffer setLength method example");

sbf.setLength(12);

System.out.println("StringBuffer contents: " + sbf);

sbf.setLength(0);

System.out.println("StringBuffer contents deleted:" + sbf);

   }

}

Convert String to long

public class StringToPrimitiveLongExample

{

public static void main(String[] args)

{

String str = new String("10");

long l = Long.parseLong(str);

System.out.println(l);

   }

}

Get Selected Item From Single Select AWT List

import java.applet.Applet;

import java.awt.Graphics;

import java.awt.List;

import java.awt.event.ItemEvent;

import java.awt.event.ItemListener;

public class GetSelectedItemFromSingleSelectExample extends Applet implements ItemListener

{  

List list = null;

public void init()

{

list = new List(5, false);

list.add("One");

list.add("Two");

list.add("Three");

list.add("Four");

list.add("Five");

list.add("Six");

list.add("Seven");

add(list);

list.addItemListener(this);

}

public void paint(Graphics g)

{

g.drawString("Selected Item: "+ list.getSelectedItem(), 10, 120);

}

public void itemStateChanged(ItemEvent arg0)

                    {

repaint();     

  }

}

Performing Binary Search on Java float Array

import java.util.Arrays;

public class BinarySearchFloatArrayExample

{

public static void main(String[] args)

{

float floatArray[] = {1.23f,2.10f,4.74f,5.34f};

Arrays.sort(floatArray);float searchValue = 4.74f;

int intResult = Arrays.binarySearch(floatArray,searchValue);

System.out.println("Result of binary search of 4.74 is : " + intResult);

searchValue = 3.33f;

intResult = Arrays.binarySearch(floatArray,searchValue);

System.out.println("Result of binary search of 3.33 is : " + intResult);

   }

}

Get Synchronized List from Java ArrayList

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

public class GetSynchronizedListFromArrayListExample

{

public static void main(String[] args)

{

ArrayList arrayList = new ArrayList();

List list = Collections.synchronizedList(arrayList);  

   }

}

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);

   }

}

Get Foreground Color Of an Applet Window

import java.applet.Applet;

import java.awt.Color;

import java.awt.Graphics;

public class GetForgroundColorExample extends Applet

{

public void paint(Graphics g)

{

  Color c = getForeground();

  g.drawString(c.toString(),50,50);

   }

}

Replace an element at specified index of Java ArrayList

import java.util.ArrayList;

public class ReplaceElementAtSpecifiedIndexArrayListExample

{

public static void main(String[] args)

{

ArrayList arrayList = new ArrayList();

arrayList.add("1");

arrayList.add("2");

arrayList.add("3");

arrayList.set(1,"REPLACED ELEMENT");

System.out.println("ArrayList contains...");

for(int index=0; index < arrayList.size(); index++)

System.out.println(arrayList.get(index));

   }

}

Replace an element at specified index of Java ArrayList

import java.util.ArrayList;

public class ReplaceElementAtSpecifiedIndexArrayListExample

{

public static void main(String[] args)

 {

ArrayList arrayList = new ArrayList();

arrayList.add("1");

arrayList.add("2");

arrayList.add("3");

arrayList.set(1,"REPLACED ELEMENT");

System.out.println("ArrayList contains...");

for(int index=0; index < arrayList.size(); index++)

System.out.println(arrayList.get(index));

   }

}

Create Custom Color Using HSB

import java.applet.Applet;

import java.awt.Color;

import java.awt.Graphics;

public class CreateCustomColorUsingHSB extends Applet

{ 

public void paint(Graphics g)

 {

Color customColor = Color.getHSBColor(0.9f,0.5f,0.8f);

this.setForeground(customColor);

g.drawString("This is a custom HSB color", 10, 50);

  }

}

Convert short primitive to Short object

public class shortToShortExample

 {

public static void main(String[] args)

{

short s = 10;

Short sObj = new Short(s);

System.out.println(sObj);

   }

}

Read short from file using DataInputStream

import java.io.DataInputStream;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

public class ReadShortFromFile

{

public static void main(String[] args)

{

 String strFilePath = "C://FileIO//readShort.txt";

   

try

{

FileInputStream fin = new FileInputStream(strFilePath);

DataInputStream din = new DataInputStream(fin);

short s = din.readShort();

System.out.println("short : " + s);

din.close();

}

catch(FileNotFoundException fe)

{

System.out.println("FileNotFoundException : " + fe);

}

catch(IOException ioe)

{

System.out.println("IOException : " + ioe);

      }

   }

}

Java String isEmpty

public class JavaStringIsEmptyExample

{

public static void main(String args[])

{

String str1 = "";

String str2 = null;

String str3 = "Hello World";

System.out.println("Is String 1 empty? :" + str1.isEmpty()); System.out.println("Is String 3 empty? :" + str3.isEmpty());

   }

}

Java float

import java.util.*;

public class JavaFloatExample

 {

public static void main(String[] args)

{

float = ;

float f = 10.4f;

System.out.println("Value of float variable f is :" + f);                

   }

}

Compare Two Numbers

public class CompareTwoNumbers

{

public static void main(String[] args)

{

int num1 = 324;

int num2 = 234;               

if(num1 > num2)

{

System.out.println(num1 + " is greater than " + num2);

}

else if(num1 < num2)

{

System.out.println(num1 + " is less than " + num2);

}

else

{

System.out.println(num1 + " is equal to " + num2);

      }

   }

}

Determine If Year Is Leap Year

public class DetermineLeapYearExample

{

 public static void main(String[] args)

{

 int year = 2004;                

 if((year % 400 == 0) || ((year % 4 == 0) && (year % 100 != 0)))

System.out.println("Year " + year + " is a leap year");

else

System.out.println("Year " + year + " is not a leap year");

  }

}

   

If Else statement

public class SimpleIfElseStatementExample

 {

public static void main(String[] args)

{

int i = 0;       

if(i == 0)

System.out.println("i is 0");

else

System.out.println("i is not 0");

    }

}

If Else If statement

public class IfElseIfElseExample

{

public static void main(String[] args)

{

int i = 10;

if(i > 100)

System.out.println("i is grater than 100");

else if(i > 50)

System.out.println("i is grater than 50");

else

System.out.println("i is less than 50");

   }

}