Wrapper class – Hey primitive, don’t worry I will wrap you and then let convert to desired respective objects!

---------------------------------------------------------------------------------------------------------------- Description :-

       For every primitive data type like byte, int,  short,  long,  float,  double, char, boolean, there are  equivalent classes Byte, Integer, Short, Long, Float, Double, Character, Boolean respectively in Java.

---------------------------------------------------------------------------------------------------------------- Key points :-

1. Mainly used to convert from one object to another. For more information, see “Program” section.

2. Only objects are allowed in collections like List, Set, Map. In collection, auto-boxing is done internally.

3. Boxing refers to converting from primitive data type (int) to its respective object (Integer).

   Example :-

   int number = 5;

   Integer numberConversion = new Integer(number);

4. Unboxing refers to converting from object (Float) to  its respective primitive data type (float).

   Example :-

   float number = 5.4f;

   Float numberConversion = new Float(number);

   numberConversion.floatValue();

5. Autoboxing refers to internal conversion from primitive data type (double) to its respective object (Double)

   Example :-

   List<Integer> list = new ArrayList<Integer>();

   list.add(1);   //autoboxing

   list.add(5); //autoboxing

---------------------------------------------------------------------------------------------------------------- Program :-

package com.thebeautifuljava.wrapper;

public class WrapperDemo {

 public static void main(String[] args) {
  // TODO Auto-generated method stub

  integerConversions(10, "10");
  System.out.println("----------------------------------------------------");
  
  doubleConversions(10.0, "10.0");
  System.out.println("----------------------------------------------------");
  
  floatConversions(10.0f, "10.0");
  System.out.println("----------------------------------------------------");
  
  short shortValue = 10;
  shortConversions(shortValue, "10");
  System.out.println("----------------------------------------------------");
  
  longConversions(10, "10");
  System.out.println("----------------------------------------------------");
  
  byte byteValue = 10;
  byteConversions(byteValue, "10");
  System.out.println("----------------------------------------------------");
 }

 /***********************BYTE CONVERSIONS*********************************/
 private static void byteConversions(byte byteValue, String numberTenString) {
  // TODO Auto-generated method stub
  Byte numberTenCoversion = new Byte(byteValue);

  byte numberTenByte = numberTenCoversion.byteValue();
  System.out.println("CONVERSION FROM Byte TO byte :" + numberTenByte);

  double numberTenDouble = numberTenCoversion.doubleValue();

  System.out
    .println("CONVERSION FROM Byte TO double :" + numberTenDouble);

  float numberTenFloat = numberTenCoversion.floatValue();
  System.out.println("CONVERSION FROM Byte TO float :" + numberTenFloat);

  int numberTenInt = numberTenCoversion.intValue();
  System.out.println("CONVERSION FROM Byte TO int :" + numberTenInt);

  long numberTenLongConversion = numberTenCoversion.longValue();

  System.out.println("CONVERSION FROM Byte TO long :"
    + numberTenLongConversion);

  short numberTenShort = numberTenCoversion.shortValue();
  System.out.println("CONVERSION FROM Byte TO short :" + numberTenShort);

  byte numberTenByteParse = Byte.parseByte(numberTenString);

  System.out.println("CONVERSION FROM String TO byte :"
    + numberTenByteParse);

  String numberTenStringConvert = Byte.toString(byteValue);

  System.out.println("CONVERSION FROM byte TO String :"
    + numberTenStringConvert);

  Byte numberTenByteConvert = Byte.valueOf(byteValue);
  System.out.println("CONVERSION FROM byte TO Byte :"
    + numberTenByteConvert);

  Byte numberTenStringByteConvert = Byte.valueOf(numberTenString);

  System.out.println("CONVERSION FROM String TO Byte :"
    + numberTenStringByteConvert);
 }

 /***********************LONG CONVERSIONS*********************************/
 private static void longConversions(long numberTen, String numberTenString) {
  // TODO Auto-generated method stub
  Long numberTenLong = new Long(numberTen);

  byte numberTenByte = numberTenLong.byteValue();
  System.out.println("CONVERSION FROM Long TO byte :" + numberTenByte);

  double numberTenDouble = numberTenLong.doubleValue();
  System.out
    .println("CONVERSION FROM Long TO double :" + numberTenDouble);

  float numberTenFloat = numberTenLong.floatValue();
  System.out.println("CONVERSION FROM Long TO float :" + numberTenFloat);

  int numberTenInt = numberTenLong.intValue();
  System.out.println("CONVERSION FROM Long TO int :" + numberTenInt);

  long numberTenLongConversion = numberTenLong.longValue();

  System.out.println("CONVERSION FROM Long TO long :"
    + numberTenLongConversion);

  short numberTenShort = numberTenLong.shortValue();
  System.out.println("CONVERSION FROM Long TO short :" + numberTenShort);

  long numberTenLongParse = Long.parseLong(numberTenString);

  System.out.println("CONVERSION FROM String TO long :"
    + numberTenLongParse);

  String numberTenStringConvert = Long.toString(numberTen);

  System.out.println("CONVERSION FROM long TO String :"
    + numberTenStringConvert);

  Long numberTenLongConvert = Long.valueOf(numberTen);
  System.out.println("CONVERSION FROM long TO Long :"
    + numberTenLongConvert);

  Long numberTenStringLongConvert = Long.valueOf(numberTenString);

  System.out.println("CONVERSION FROM String TO Long :"
    + numberTenStringLongConvert);
 }

  /***********************SHORT CONVERSIONS*********************************/
 private static void shortConversions(short numberTen, String numberTenString) {
  // TODO Auto-generated method stub
  Short numberTenShort = new Short(numberTen);

  byte numberTenByte = numberTenShort.byteValue();
  System.out.println("CONVERSION FROM Short TO byte :" + numberTenByte);

  double numberTenDouble = numberTenShort.doubleValue();
  System.out.println("CONVERSION FROM Short TO double :"
    + numberTenDouble);

  float numberTenFloat = numberTenShort.floatValue();
  System.out.println("CONVERSION FROM Short TO float :" + numberTenFloat);

  int numberTenInt = numberTenShort.intValue();
  System.out.println("CONVERSION FROM Short TO int :" + numberTenInt);

  long numberTenLong = numberTenShort.longValue();
  System.out.println("CONVERSION FROM Short TO long :" + numberTenLong);

  short numberTenShortConversion = numberTenShort.shortValue();

  System.out.println("CONVERSION FROM Short TO short :"
    + numberTenShortConversion);

  short numberTenShortParse = Short.parseShort(numberTenString);

  System.out.println("CONVERSION FROM String TO short :"
    + numberTenShortParse);

  String numberTenStringConvert = Short.toString(numberTen);

  System.out.println("CONVERSION FROM short TO String :"
    + numberTenStringConvert);

  Short numberTenShortConvert = Short.valueOf(numberTen);

  System.out.println("CONVERSION FROM short TO Integer :"
    + numberTenShortConvert);

  Short numberTenStringShortConvert = Short.valueOf(numberTenString);

  System.out.println("CONVERSION FROM String TO Integer :"
    + numberTenStringShortConvert);
 }

 /***********************FLOAT CONVERSIONS*********************************/
 private static void floatConversions(float numberFloat,
   String numberFloatString) {
  // TODO Auto-generated method stub
  Float numberTenFloat = new Float(numberFloat);

  byte numberTenByte = numberTenFloat.byteValue();
  System.out.println("CONVERSION FROM Float TO byte :" + numberTenByte);

  double numberTenDouble = numberTenFloat.doubleValue();
  System.out.println("CONVERSION FROM Float TO double :"
    + numberTenDouble);

  float numberTenFloatConversion = numberTenFloat.floatValue();

  System.out.println("CONVERSION FROM Float TO float :"
    + numberTenFloatConversion);

  int numberTenInt = numberTenFloat.intValue();
  System.out.println("CONVERSION FROM Float TO int :" + numberTenInt);

  long numberTenLong = numberTenFloat.longValue();
  System.out.println("CONVERSION FROM Float TO long :" + numberTenLong);

  short numberTenShort = numberTenFloat.shortValue();
  System.out.println("CONVERSION FROM Float TO short :" + numberTenShort);

  float numberTenFloatParse = Float.parseFloat(numberFloatString);

  System.out.println("CONVERSION FROM String TO float :"
    + numberTenFloatParse);

  String numberTenStringConvert = Float.toString(numberFloat);

  System.out.println("CONVERSION FROM float TO String :"
    + numberTenStringConvert);

  Float numberTenFloatConvert = Float.valueOf(numberFloat);

  System.out.println("CONVERSION FROM float TO Float :"
    + numberTenFloatConvert);

  Float numberTenStringFloatConvert = Float.valueOf(numberFloatString);

  System.out.println("CONVERSION FROM String TO Float :"
    + numberTenStringFloatConvert);

 }

 /***********************DOUBLE CONVERSIONS*********************************/
 private static void doubleConversions(double numberTen,
   String numberTenString) {

  Double numberTenDouble = new Double(numberTen);

  byte numberTenByte = numberTenDouble.byteValue();
  System.out.println("CONVERSION FROM Double TO byte :" + numberTenByte);

  double numberTenDoubleConversion = numberTenDouble.doubleValue();

  System.out.println("CONVERSION FROM Double TO double :"
    + numberTenDoubleConversion);

  float numberTenFloat = numberTenDouble.floatValue();
  System.out
    .println("CONVERSION FROM Double TO float :" + numberTenFloat);

  int numberTenInt = numberTenDouble.intValue();
  System.out.println("CONVERSION FROM Double TO int :" + numberTenInt);

  long numberTenLong = numberTenDouble.longValue();
  System.out.println("CONVERSION FROM Double TO long :" + numberTenLong);

  short numberTenShort = numberTenDouble.shortValue();
  System.out
    .println("CONVERSION FROM Double TO short :" + numberTenShort);

  double numberTenDoubleParse = Double.parseDouble(numberTenString);

  System.out.println("CONVERSION FROM String TO double :"
    + numberTenDoubleParse);

  String numberTenStringConvert = Double.toString(numberTen);

  System.out.println("CONVERSION FROM double TO String :"
    + numberTenStringConvert);

  Double numberTenDoubleConvert = Double.valueOf(numberTenString);

  System.out.println("CONVERSION FROM double TO Double :"
    + numberTenDoubleConvert);

  Double numberTenStringDoubleConvert = Double.valueOf(numberTenString);

  System.out.println("CONVERSION FROM String TO Double :"
    + numberTenStringDoubleConvert);

 }

 /***********************INTEGER CONVERSIONS*********************************/
 private static void integerConversions(int numberTen, String numberTenString) {

  // TODO Auto-generated method stub
  Integer numberTenInteger = new Integer(numberTen);

  byte numberTenByte = numberTenInteger.byteValue();
  System.out.println("CONVERSION FROM Integer TO byte :" + numberTenByte);

  double numberTenDouble = numberTenInteger.doubleValue();

  System.out.println("CONVERSION FROM Integer TO double :"
    + numberTenDouble);

  float numberTenFloat = numberTenInteger.floatValue();
  System.out.println("CONVERSION FROM Integer TO float :"
    + numberTenFloat);

  int numberTenInt = numberTenInteger.intValue();
  System.out.println("CONVERSION FROM Integer TO int :" + numberTenInt);

  long numberTenLong = numberTenInteger.longValue();
  System.out.println("CONVERSION FROM Integer TO long :" + numberTenLong);

  short numberTenShort = numberTenInteger.shortValue();
  System.out.println("CONVERSION FROM Integer TO short :"
    + numberTenShort);

  int numberTenIntParse = Integer.parseInt(numberTenString);
  System.out.println("CONVERSION FROM String TO int :"
    + numberTenIntParse);

  String numberTenStringConvert = Integer.toString(numberTen);

  System.out.println("CONVERSION FROM int TO String :"
    + numberTenStringConvert);

  Integer numberTenIntegerConvert = Integer.valueOf(numberTen);

  System.out.println("CONVERSION FROM int TO Integer :"
    + numberTenIntegerConvert);

  Integer numberTenStringIntegerConvert = Integer
    .valueOf(numberTenString);
  System.out.println("CONVERSION FROM String TO Integer :"
    + numberTenStringIntegerConvert);

 }

}

---------------------------------------------------------------------------------------------------------------- References :-

https://docs.oracle.com/javase/7/docs/api/java/lang/Integer.html

https://docs.oracle.com/javase/7/docs/api/java/lang/Float.html

https://docs.oracle.com/javase/7/docs/api/java/lang/Double.html

https://docs.oracle.com/javase/7/docs/api/java/lang/Short.html

https://docs.oracle.com/javase/7/docs/api/java/lang/Long.html

https://docs.oracle.com/javase/7/docs/api/java/lang/Byte.html