Finding fibonacci number series in java

Fibonacci series : a series of numbers in which each number ( Fibonacci number ) is the sum of the two preceding numbers. The simplest is the series 1, 1, 2, 3, 5, 8, 13,21,34 ,55,89 etc.

Solution1 using Recursion : 

/**code to get nth fibonacci number **/

public static int fibonacciNumbers(int n){

  if(n <= 0 ||  n == 1){

   return 1;

  } else {

    return fibonacciNumbers(n-1) + fibonacciNumbers(n-2);

   }

 }

public static void main(String[] args){

int numberOfFibonacci  = 15;

  long start = System.currentTimeMillis();

  java.util.List<Integer> fibnocList = new ArrayList<>();

  for (int i = 0; i <= numberOfFibonacci; i++) {

   fibnocList.add(fibonacciNumbers(i));

  }

  System.out.println(fibnocList);

  long end = System.currentTimeMillis();

  System.out.println("total time taken=" + (end -start)  +  " ms");

 }
Output : 

[1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987]




total time taken=1 ms

Note : Till 40th element its able to print fibonacci numbers after that time of execution

increase exponentially.

Time complexity is O(n) & Space complexity O(n).

Solution2 using  without Recursion : 

       
/**printing the series of fibonacci number upto length n  **/


public static void fibonacciSeries(int n){

  int[] fibArray = new int[n];

  if(n < 0 ){

   System.out.println("invalid value");

  } else {

     for (int i = 0; i < n; i++) {

      if(i== 0 || i==1){

       fibArray[i] =1;

      } else {

       fibArray[i] =  fibArray[i-1] + fibArray[i-2];

      }

   }

   }

  System.out.println("fibonacci number upto lenth n=" + n + " and series=" + Arrays.toString(fibArray));

 }

public static void main(String[] args){

  long start = System.currentTimeMillis();

  fibonacciSeries(20);

  long end = System.currentTimeMillis();

  System.out.println("total time taken=" + (end -start)  +  " ms");

 }

Note : Time complexity O(n) and space complexity is in place as using the arrays.

Output: 



fibonacci number upto lenth n=20 and series=[1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 

233, 377, 610, 987, 1597, 2584, 4181, 6765]

total time taken=0 ms
      

In both the solutions number 2 solutions is best possible solution with respect to time and space complexity.

Enjoy the code and enjoy the journey of Java!!!!

Finding all permutations of a String in Java

There are many ways of finding the permutations of a string . From the mathematics point of view there can be n! permutations where n is number of  character in the string.

Solution1  :

Use recursion.

• Try each of the letters in turn as the first letter and then find all the permutations of the remaining letters using a recursive call.
• The base case is when the input is an empty string the only permutation is the empty string.

       

public static void perm(String s){

  if(s ==null || s.isEmpty()){

         return;

       }

perm("", s);

}


public static void perm(String prefix , String s){

     if(s.length() == 0){

        System.out.println(prefix);

      } else {

   int stringLength = s.length();

   for (int i = 0; i < stringLength; i++) {

   perm(prefix + s.charAt(i), s.substring(0, i) + s.substring(i+1));

    }

}

}

public static void main(String[] args){

  perm("abc");

}
output : 

abc

acb

bac

bca

cab

cba

Time Complexity would be : O(n*n!) as for each element you required n-1 permutations of the 

string so overall n! permutations.




Space complexity would be : O(n)



Note 2: Time taken to execute the method for various length of string:







for n=10 and 10!=3628800 number and total time taken to complete the output is = 93.31 sec

for n=9 and 9!=362880 number and total time taken to complete the output is = 6.312 sec

for n=8 and 8!=40320 number and total time taken to complete the output is = 365 ms

for n=7 and 7!=5040 number and total time taken to complete the output is = 92 ms

for n=6 and 6!=720 number and total time taken to complete the output is = 43 ms

for n=5 and 5!=120 number and total time taken to complete the output is =4 ms

for n=4 and 4!=24 number and total time taken to complete the output is = 1 ms

for n=3 and 3!=6 number and total time taken to complete the output is = 1 ms

for n=2 and 2!=2 number and total time taken to complete the output is = 0 ms

Solution2 :

Use recursion and swapping.

• Try each of the index in turn as the current index and then find all the permutations of the remaining letters using a recursive call and swapping the element to the current index.
• The base case is when the input  is an 0 index the only permutation is the permutated string.

private static void doPerm(StringBuffer str, int index){
     if(index <= 0)

         System.out.println(str);           

     else { 

      int n = str.length();

         int currPos = n-index;


doPerm(str, index-1);
         for (int i = currPos+1; i < n; i++) {

             swap(str,currPos, i);

             doPerm(str, index-1);

             swap(str,i, currPos);


         }
     }

 }

private  static void swap(StringBuffer str, int pos1, int pos2){


     char t1 = str.charAt(pos1);

     str.setCharAt(pos1, str.charAt(pos2));

}


public static void main(String[] args){
  long start = System.currentTimeMillis();

  String str = "abcd";

  StringBuffer strBuf = new StringBuffer(str);

         doPerm(strBuf,str.length());

  long end = System.currentTimeMillis();

  System.out.println("total time taken=" + (end -start)  +  " ms");

 }





Time Complexity would be : O(n*n!) as for each element you required n-1 permutations of the 
string so overall n! permutations.But the use of String buffer and in memory swapping 

the elements reduces the execution time. 





Space complexity would be : O(n)



Note 2: Time taken to execute the method for various length of string:







for n=10 and 10!=3628800 number and total time taken to complete the output is = 33.31 sec

for n=9 and 9!=362880 number and total time taken to complete the output is = 3.312 sec

for n=8 and 8!=40320 number and total time taken to complete the output is = 185 ms

for n=7 and 7!=5040 number and total time taken to complete the output is = 42 ms

for n=6 and 6!=720 number and total time taken to complete the output is = 13 ms

for n=5 and 5!=120 number and total time taken to complete the output is =4 ms

for n=4 and 4!=24 number and total time taken to complete the output is = 1 ms

for n=3 and 3!=6 number and total time taken to complete the output is = 1 ms

for n=2 and 2!=2 number and total time taken to complete the output is = 0 ms





This solution is seems to be more  optimal solution as compare to solution 1.So 
highly recommended. 

solution 1 & solution 2 are taking same time upto 5 elements in the string but as we grow larger say upto 10 characters , solution 2 fit the most with respect to the time complexity and taking 1/3rd time as compare to solution1. It uses the technique to swap the elements in memory and use of string buffer reduces the time.



Solution 2 is highly recommended for finding the permutations of the string.

Two solutions are being mentioned and compare with the time . Clearly 2nd solution is much more optimal solution and its uses in memory swapping the element and making permutation of the other string excluding the current index character. Above two solutions gives all the permutations of a string while to remove the duplicates output need to be write in a Set to avoid any duplicates.

Solution 3 without recursions and without duplicates :  

      

public static Set<String> generatePermutation(String input){

  Set<String> set = new HashSet<String>();

  if(input == null){ return null; }

  if (input == "") {return set;}

  Character a = input.charAt(0);

  if (input.length() > 1){

   input = input.substring(1);

   Set<String> permSet = generatePermutation(input);

   for (String x : permSet){

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

     set.add(x.substring(0, i) + a + x.substring(i));

    }

   }

  } else {

   set.add(a + "");

  }

  return set;

 }

public static void main(String[] args){

  long start = System.currentTimeMillis();

  String str = "AACC";

  System.out.println(generatePermutation(str));

  long end = System.currentTimeMillis();

  System.out.println("total time taken=" + (end -start)  +  " ms");

 }
Output : 



[CACA, ACAC, ACCA, AACC, CCAA, CAAC]

total time taken=1 ms
Note : No duplicates are in the output and this is the most optimal solution for 

finding the permutations  of a string.       
 

Enjoy coding and enjoy Java!!!!!

Virus affected folder having files is not displaying - How to see the files on Windows

In case of virus affected folders are many time doesn't show the content in the folder. If one open the folder properties then number of files are shown but on entering folder , no file is visible.

To resolve it following 2 steps are to be followed : 

1 .  Show hidden Files,Folders and Drives : 

Go to Control Panel  --> Appearance  and Personalization  --> Folder Options -- > Show hidden files and folders -- > Click on radio button [Show hidden files,folders and drives] 

Now all the hidden files , folders and drives would be visible.

In case of  files are still missing in the folder though size of the folder is showing number of files present in the folder --> follow the step2 

2. Displaying the hidden files of the folder due to affect of  Virus : 

a ) Use some antivirus to scan the folder to clean up the virus.
b)  Go to Start --> Run --> Type cmd and press Enter.

Assuming your drive letter as F: where a folder is affected by virus and folder is not displaying any files though they are exist in the folder.

Copy this command :

attrib -h -r -s /s /d f:\*.*

copy the above command --> Right-click in the Command prompt to paste it --> Enter

Now check your drive for the files in the folder -- > It will display entire files in the folder.

Enjoy the virus free access of the files in your drives. Don't forget to protect your system with an antivirus.

Generating the Pdf from HTML

Generating PDF from PDF template is a time & memory consuming process. It's sometime not feasible to use it while processing larger data set.

One of the very good features of creating PDF using HTML is appropriate and simple to use and easy to maintain.

There are many libraries are available for reference  PDF library link 

I will be discuss here itextpdf library of creation as it is simple and easy to maintain. For the Maven based project pom entry :

<!-- https://mvnrepository.com/artifact/com.itextpdf/itextpdf -->    
<dependency>
    &lt;d&gt;<groupid>com.itextpdf</groupid>
    <artifactid>itextpdf</artifactid>
    <version>5.5.9</version>
</dependency>
   
 

Following is the code snippet to use for conversion of html into pdf :

import com.itextpdf.text.Document;

import com.itextpdf.text.html.simpleparser.HTMLWorker;

import com.itextpdf.text.pdf.PdfWriter;

@SuppressWarnings("deprecation")

public static void createPDFUsingHtml(String htmlFilePath,String outputPDFFilePath){

          try {

   Document document = new Document();

   OutputStream file = new FileOutputStream(outputPDFFilePath);

   PdfWriter writer = PdfWriter.getInstance(document,file );

   ///if want to keep password encrypted then add password here else passwordless pdf will be created

   writer.setEncryption("".getBytes(), "".getBytes(),PdfWriter.ALLOW_PRINTING, PdfWriter.STANDARD_ENCRYPTION_128);

   document.open();

   HTMLWorker htmlWorker = new HTMLWorker(document);

   String htmlcontent = readFile(htmlFilePath);

   htmlWorker.parse(new StringReader(htmlcontent));

   document.close();

  } catch (Exception e)

  {

      e.printStackTrace();

  }

 }

When run a main  program on the html  test.html

   

public static void main(String[] args){

  createPDFUsingHtml("/Users/test/test.html", "/Users/test/test.pdf");

 }

Output of the created pdf : test.pdf

Your PDF is ready with a very  simple way and doesn't require any extra effort of creation of the pdf template. Instead just make a simple HTML  template which can be created from any online tool .
Just make your html ready and then your PDF will be created immediately.

Enjoy Coding !!!!

Reading file in Java

Reading file data is something used day to day life of a developer. Java had continuously  worked on the improvisation of file reading and writing as these are heavy process sometime and memory consuming.

Lets take case by case :

1. Reading a file data using FileReader : 

Method to used :

public static String readFile(String filePath) {
  StringBuilder sb = new StringBuilder();
  BufferedReader br = null;
  try {
   br = new BufferedReader(new FileReader(filePath));
   String line = br.readLine();
   while (line != null) {
    sb.append(line);
    sb.append("\n");
    line = br.readLine();
   }
  } catch(Exception e){
   e.printStackTrace();
  } finally {
   if(br!=null){
    try {
     br.close();
    } catch (IOException e) {
     e.printStackTrace();
    }
   }
  }
  return sb.toString();
 }   

2. Reading a file data using NIO: 

Method to used :

public static String readFileUsingNio(String filePath){

  String content = null;

   try {

   content = new String(Files.readAllBytes(Paths.get(filePath)));

  } catch (Exception e) {

      e.printStackTrace();

  }

  return content;

 } 

There are other libraries available of apache common etc where utility of reading file is given.

But as an Architect I feel adding Non Blocking I/O  features in Java 7  is being one of the finest revolution in the I/O  operation . It is always recommended to use Java features are they are fully trusted and robust. Using lesser third party libraries is always advisable as lesser dependencies means lesser chances of getting the bug and code maintainability remains cleans. 

To check if object attribute exist or not in Freemarker

Starting from freemarker 2.3.7, you can use this syntax :

${(object.attribute)!}

or, if you want display a default text when the attribute is null :

${(object.attribute)!"some text”}

OR you can use the ??  test operator:

This checks if the attribute of the object is not null:

<#if object.attribute??></#if>

This checks if object or attribute is not null:

<#if (object.attribute)??></#if>

OR you can use the ?has_content operator :

<#if object.attribute?has_content>

          Attribute exist!!

</#if>

OR you can use the _exists operator :

<#if_exists object.attribute>

  Attribute exists = ${ object.attribute} 

</#if_exists>

Use of Freemarker :  

Freemarker is being used massively in the Emailing , SMS, Content Feeder and also the View part of the MVC frameworks like Spring.

Maven Dependency : 

<!-- https://mvnrepository.com/artifact/org.freemarker/freemarker -->

<dependency>

    <groupId>org.freemarker</groupId>

    <artifactId>freemarker</artifactId>

    <version>2.3.23</version>

</dependency>

Happy to help post your query in the blog.

Iteration of a Collection in Freemarker Template

In this blog , we will be demonstrating the iteration of Java Collection viz. Map , List etc with the different examples in the freemarker templates. As all the Java collection implements the Iterable interface, so iteration technique is same for different sort of collections.

    

1. Iteration of a Map in Freemarker Template (FTL)

Lets look how the Map iteration looks like in Java : 

Map<String,Object> personMap = new HashMap<String, Object>();

person.put("name","sachin");

person.put("age, 29);

person.put("occupation","blogger");

for (String key : person.keySet()) {

           System.out.println("key=" + key + ", value=" + person.get(key));

}

Similar Map if we need to iterate in freemarker template then it's as follow: 

<#if personMap?has_content>

<#list personMap?keys as key>

"keys= "${key}, "value=" ${personMap[key]}; 

</#list>

</#if>

Here ?keys is a built-in function in freemarker just like keySet() in Java to 

provide the list of all the keys.

Output :

---------------------------------------

key=name, value=sachin

key=age, value=29

key=occupation, value=blogger

---------------------------------------

2. Iteration of a List in Freemarker Template (FTL)

Lets look how the List iteration looks like in Java 

List<String> nameList = new ArrayList<>();

nameList.add("Amar");

nameList.add("Akbar");

nameList.add("Anthony");

for (String name : nameList) {

System.out.println("name=" + name);

}

Similar List if we need to iterate in freemarker template then it's as follow: 

<#if nameList?has_content>

<#list nameList as name>

"name= "${name}

</#list>

</#if>

Output:

-------------------

name=Amar

name=Akbar

name=Anthony

--------------------------

Here has_content is a built-in function in freemarker just to check the emptiness 

of the collection return true if non-empty else return false.

Enjoy the power of the freemarker template for various purpose like Email Templating , View part of the framework , Generating News Feed etc .

Installing Freemarker IDE in Eclipse

Steps to install Freemarker IDE in eclipse Mars  :

1. Go to Help  --> Install New Software 
2.  Out of the  following URL for updating site of http://download.jboss.org/jbosstools/updates/stable/mars/
3. For Older eclipse version use from the following 

• http://download.jboss.org/jbosstools/updates/stable/luna/
• http://download.jboss.org/jbosstools/updates/stable/juno/
• http://download.jboss.org/jbosstools/updates/stable/indigo/
• http://download.jboss.org/jbosstools/updates/stable/helios/

 4.  Update the  work with : 

         http://download.jboss.org/jbosstools/updates/stable/mars/    and select JBoss                                        Application Developers ---> Select FreeMarker IDE

4. Click on Finish and then FreeMarker IDE is installed on your eclipse with a restart.

Congrats your template engine is ready to work !!!!!!!!

TimeZone Ids In Java and Date Serialization with TimeZone using Jackson

1. There are total of 617 number  of  supported time zone IDs  available in the JDK version 1.8  and following is the list of all the IDs obtained from the java.util.TimeZone  :
--------------------

Africa/Abidjan

Africa/Accra

Africa/Addis_Ababa

Africa/Algiers

Africa/Asmara

Africa/Asmera

Africa/Bamako

Africa/Bangui

Africa/Banjul

Africa/Bissau

Africa/Blantyre

Africa/Brazzaville

Africa/Bujumbura

Africa/Cairo

Africa/Casablanca

Africa/Ceuta

Africa/Conakry

Africa/Dakar

Africa/Dar_es_Salaam

Africa/Djibouti

Africa/Douala

Africa/El_Aaiun

Africa/Freetown

Africa/Gaborone

Africa/Harare

Africa/Johannesburg

Africa/Juba

Africa/Kampala

Africa/Khartoum

Africa/Kigali

Africa/Kinshasa

Africa/Lagos

Africa/Libreville

Africa/Lome

Africa/Luanda

Africa/Lubumbashi

Africa/Lusaka

Africa/Malabo

Africa/Maputo

Africa/Maseru

Africa/Mbabane

Africa/Mogadishu

Africa/Monrovia

Africa/Nairobi

Africa/Ndjamena

Africa/Niamey

Africa/Nouakchott

Africa/Ouagadougou

Africa/Porto-Novo

Africa/Sao_Tome

Africa/Timbuktu

Africa/Tripoli

Africa/Tunis

Africa/Windhoek

America/Adak

America/Anchorage

America/Anguilla

America/Antigua

America/Araguaina

America/Argentina/Buenos_Aires

America/Argentina/Catamarca

America/Argentina/ComodRivadavia

America/Argentina/Cordoba

America/Argentina/Jujuy

America/Argentina/La_Rioja

America/Argentina/Mendoza

America/Argentina/Rio_Gallegos

America/Argentina/Salta

America/Argentina/San_Juan

America/Argentina/San_Luis

America/Argentina/Tucuman

America/Argentina/Ushuaia

America/Aruba

America/Asuncion

America/Atikokan

America/Atka

America/Bahia

America/Bahia_Banderas

America/Barbados

America/Belem

America/Belize

America/Blanc-Sablon

America/Boa_Vista

America/Bogota

America/Boise

America/Buenos_Aires

America/Cambridge_Bay

America/Campo_Grande

America/Cancun

America/Caracas

America/Catamarca

America/Cayenne

America/Cayman

America/Chicago

America/Chihuahua

America/Coral_Harbour

America/Cordoba

America/Costa_Rica

America/Creston

America/Cuiaba

America/Curacao

America/Danmarkshavn

America/Dawson

America/Dawson_Creek

America/Denver

America/Detroit

America/Dominica

America/Edmonton

America/Eirunepe

America/El_Salvador

America/Ensenada

America/Fort_Wayne

America/Fortaleza

America/Glace_Bay

America/Godthab

America/Goose_Bay

America/Grand_Turk

America/Grenada

America/Guadeloupe

America/Guatemala

America/Guayaquil

America/Guyana

America/Halifax

America/Havana

America/Hermosillo

America/Indiana/Indianapolis

America/Indiana/Knox

America/Indiana/Marengo

America/Indiana/Petersburg

America/Indiana/Tell_City

America/Indiana/Vevay

America/Indiana/Vincennes

America/Indiana/Winamac

America/Indianapolis

America/Inuvik

America/Iqaluit

America/Jamaica

America/Jujuy

America/Juneau

America/Kentucky/Louisville

America/Kentucky/Monticello

America/Knox_IN

America/Kralendijk

America/La_Paz

America/Lima

America/Los_Angeles

America/Louisville

America/Lower_Princes

America/Maceio

America/Managua

America/Manaus

America/Marigot

America/Martinique

America/Matamoros

America/Mazatlan

America/Mendoza

America/Menominee

America/Merida

America/Metlakatla

America/Mexico_City

America/Miquelon

America/Moncton

America/Monterrey

America/Montevideo

America/Montreal

America/Montserrat

America/Nassau

America/New_York

America/Nipigon

America/Nome

America/Noronha

America/North_Dakota/Beulah

America/North_Dakota/Center

America/North_Dakota/New_Salem

America/Ojinaga

America/Panama

America/Pangnirtung

America/Paramaribo

America/Phoenix

America/Port-au-Prince

America/Port_of_Spain

America/Porto_Acre

America/Porto_Velho

America/Puerto_Rico

America/Rainy_River

America/Rankin_Inlet

America/Recife

America/Regina

America/Resolute

America/Rio_Branco

America/Rosario

America/Santa_Isabel

America/Santarem

America/Santiago

America/Santo_Domingo

America/Sao_Paulo

America/Scoresbysund

America/Shiprock

America/Sitka

America/St_Barthelemy

America/St_Johns

America/St_Kitts

America/St_Lucia

America/St_Thomas

America/St_Vincent

America/Swift_Current

America/Tegucigalpa

America/Thule

America/Thunder_Bay

America/Tijuana

America/Toronto

America/Tortola

America/Vancouver

America/Virgin

America/Whitehorse

America/Winnipeg

America/Yakutat

America/Yellowknife

Antarctica/Casey

Antarctica/Davis

Antarctica/DumontDUrville

Antarctica/Macquarie

Antarctica/Mawson

Antarctica/McMurdo

Antarctica/Palmer

Antarctica/Rothera

Antarctica/South_Pole

Antarctica/Syowa

Antarctica/Troll

Antarctica/Vostok

Arctic/Longyearbyen

Asia/Aden

Asia/Almaty

Asia/Amman

Asia/Anadyr

Asia/Aqtau

Asia/Aqtobe

Asia/Ashgabat

Asia/Ashkhabad

Asia/Baghdad

Asia/Bahrain

Asia/Baku

Asia/Bangkok

Asia/Beirut

Asia/Bishkek

Asia/Brunei

Asia/Calcutta

Asia/Chita

Asia/Choibalsan

Asia/Chongqing

Asia/Chungking

Asia/Colombo

Asia/Dacca

Asia/Damascus

Asia/Dhaka

Asia/Dili

Asia/Dubai

Asia/Dushanbe

Asia/Gaza

Asia/Harbin

Asia/Hebron

Asia/Ho_Chi_Minh

Asia/Hong_Kong

Asia/Hovd

Asia/Irkutsk

Asia/Istanbul

Asia/Jakarta

Asia/Jayapura

Asia/Jerusalem

Asia/Kabul

Asia/Kamchatka

Asia/Karachi

Asia/Kashgar

Asia/Kathmandu

Asia/Katmandu

Asia/Khandyga

Asia/Kolkata

Asia/Krasnoyarsk

Asia/Kuala_Lumpur

Asia/Kuching

Asia/Kuwait

Asia/Macao

Asia/Macau

Asia/Magadan

Asia/Makassar

Asia/Manila

Asia/Muscat

Asia/Nicosia

Asia/Novokuznetsk

Asia/Novosibirsk

Asia/Omsk

Asia/Oral

Asia/Phnom_Penh

Asia/Pontianak

Asia/Pyongyang

Asia/Qatar

Asia/Qyzylorda

Asia/Rangoon

Asia/Riyadh

Asia/Saigon

Asia/Sakhalin

Asia/Samarkand

Asia/Seoul

Asia/Shanghai

Asia/Singapore

Asia/Srednekolymsk

Asia/Taipei

Asia/Tashkent

Asia/Tbilisi

Asia/Tehran

Asia/Tel_Aviv

Asia/Thimbu

Asia/Thimphu

Asia/Tokyo

Asia/Ujung_Pandang

Asia/Ulaanbaatar

Asia/Ulan_Bator

Asia/Urumqi

Asia/Ust-Nera

Asia/Vientiane

Asia/Vladivostok

Asia/Yakutsk

Asia/Yekaterinburg

Asia/Yerevan

Atlantic/Azores

Atlantic/Bermuda

Atlantic/Canary

Atlantic/Cape_Verde

Atlantic/Faeroe

Atlantic/Faroe

Atlantic/Jan_Mayen

Atlantic/Madeira

Atlantic/Reykjavik

Atlantic/South_Georgia

Atlantic/St_Helena

Atlantic/Stanley

Australia/ACT

Australia/Adelaide

Australia/Brisbane

Australia/Broken_Hill

Australia/Canberra

Australia/Currie

Australia/Darwin

Australia/Eucla

Australia/Hobart

Australia/LHI

Australia/Lindeman

Australia/Lord_Howe

Australia/Melbourne

Australia/NSW

Australia/North

Australia/Perth

Australia/Queensland

Australia/South

Australia/Sydney

Australia/Tasmania

Australia/Victoria

Australia/West

Australia/Yancowinna

Brazil/Acre

Brazil/DeNoronha

Brazil/East

Brazil/West

CET

CST6CDT

Canada/Atlantic

Canada/Central

Canada/East-Saskatchewan

Canada/Eastern

Canada/Mountain

Canada/Newfoundland

Canada/Pacific

Canada/Saskatchewan

Canada/Yukon

Chile/Continental

Chile/EasterIsland

Cuba

EET

EST5EDT

Egypt

Eire

Etc/GMT

Etc/GMT+0

Etc/GMT+1

Etc/GMT+10

Etc/GMT+11

Etc/GMT+12

Etc/GMT+2

Etc/GMT+3

Etc/GMT+4

Etc/GMT+5

Etc/GMT+6

Etc/GMT+7

Etc/GMT+8

Etc/GMT+9

Etc/GMT-0

Etc/GMT-1

Etc/GMT-10

Etc/GMT-11

Etc/GMT-12

Etc/GMT-13

Etc/GMT-14

Etc/GMT-2

Etc/GMT-3

Etc/GMT-4

Etc/GMT-5

Etc/GMT-6

Etc/GMT-7

Etc/GMT-8

Etc/GMT-9

Etc/GMT0

Etc/Greenwich

Etc/UCT

Etc/UTC

Etc/Universal

Etc/Zulu

Europe/Amsterdam

Europe/Andorra

Europe/Athens

Europe/Belfast

Europe/Belgrade

Europe/Berlin

Europe/Bratislava

Europe/Brussels

Europe/Bucharest

Europe/Budapest

Europe/Busingen

Europe/Chisinau

Europe/Copenhagen

Europe/Dublin

Europe/Gibraltar

Europe/Guernsey

Europe/Helsinki

Europe/Isle_of_Man

Europe/Istanbul

Europe/Jersey

Europe/Kaliningrad

Europe/Kiev

Europe/Lisbon

Europe/Ljubljana

Europe/London

Europe/Luxembourg

Europe/Madrid

Europe/Malta

Europe/Mariehamn

Europe/Minsk

Europe/Monaco

Europe/Moscow

Europe/Nicosia

Europe/Oslo

Europe/Paris

Europe/Podgorica

Europe/Prague

Europe/Riga

Europe/Rome

Europe/Samara

Europe/San_Marino

Europe/Sarajevo

Europe/Simferopol

Europe/Skopje

Europe/Sofia

Europe/Stockholm

Europe/Tallinn

Europe/Tirane

Europe/Tiraspol

Europe/Uzhgorod

Europe/Vaduz

Europe/Vatican

Europe/Vienna

Europe/Vilnius

Europe/Volgograd

Europe/Warsaw

Europe/Zagreb

Europe/Zaporozhye

Europe/Zurich

GB

GB-Eire

GMT

GMT0

Greenwich

Hongkong

Iceland

Indian/Antananarivo

Indian/Chagos

Indian/Christmas

Indian/Cocos

Indian/Comoro

Indian/Kerguelen

Indian/Mahe

Indian/Maldives

Indian/Mauritius

Indian/Mayotte

Indian/Reunion

Iran

Israel

Jamaica

Japan

Kwajalein

Libya

MET

MST7MDT

Mexico/BajaNorte

Mexico/BajaSur

Mexico/General

NZ

NZ-CHAT

Navajo

PRC

PST8PDT

Pacific/Apia

Pacific/Auckland

Pacific/Bougainville

Pacific/Chatham

Pacific/Chuuk

Pacific/Easter

Pacific/Efate

Pacific/Enderbury

Pacific/Fakaofo

Pacific/Fiji

Pacific/Funafuti

Pacific/Galapagos

Pacific/Gambier

Pacific/Guadalcanal

Pacific/Guam

Pacific/Honolulu

Pacific/Johnston

Pacific/Kiritimati

Pacific/Kosrae

Pacific/Kwajalein

Pacific/Majuro

Pacific/Marquesas

Pacific/Midway

Pacific/Nauru

Pacific/Niue

Pacific/Norfolk

Pacific/Noumea

Pacific/Pago_Pago

Pacific/Palau

Pacific/Pitcairn

Pacific/Pohnpei

Pacific/Ponape

Pacific/Port_Moresby

Pacific/Rarotonga

Pacific/Saipan

Pacific/Samoa

Pacific/Tahiti

Pacific/Tarawa

Pacific/Tongatapu

Pacific/Truk

Pacific/Wake

Pacific/Wallis

Pacific/Yap

Poland

Portugal

ROK

Singapore

SystemV/AST4

SystemV/AST4ADT

SystemV/CST6

SystemV/CST6CDT

SystemV/EST5

SystemV/EST5EDT

SystemV/HST10

SystemV/MST7

SystemV/MST7MDT

SystemV/PST8

SystemV/PST8PDT

SystemV/YST9

SystemV/YST9YDT

Turkey

UCT

US/Alaska

US/Aleutian

US/Arizona

US/Central

US/East-Indiana

US/Eastern

US/Hawaii

US/Indiana-Starke

US/Michigan

US/Mountain

US/Pacific

US/Pacific-New

US/Samoa

UTC

Universal

W-SU

WET

Zulu

EST

HST

MST

ACT

AET

AGT

ART

AST

BET

BST

CAT

CNT

CST

CTT

EAT

ECT

IET

IST

JST

MIT

NET

NST

PLT

PNT

PRT

PST

SST

VST

-----------------------

2. In the Jackson setting the Timezone can help in the serialization of the Date data correct with the given timezone , there are two ways of setting the timezone for Jackson frequently used in the Spring framework : 

a) Using Object wrapper : 

         ObjectMapper mapper = new ObjectMapper();

         DateFormat dateFormat = new SimpleDateFormat("dd-MM-yyyy'T'HH:mm:ss.SSSZ");

         dateFormat.setTimeZone(TimeZone.getTimeZone("IST"));

         mapper.setDateFormat(dateFormat);

b)  In the  Jackson 2.x version using the  annotation : 

@JsonFormat(shape=JsonFormat.Shape.STRING,pattern="dd-MM-yyyy'T'HH:mm:ss.SSSZ", timezone="IST")

private Date date;