There three Distributed Commit Protocols :
  1. One-phase Commit
  2. Two-phase Commit
  3. Three-phase Commit
Requirements:
  1. Eclipse IDE 
Instruction to Run the code: 
  1. First run the Server.java 
  2. Then run multiple times Client.java
  3. To see output Go to Console -> Client of Small Computer icon (Display Selected Console)
JAVA Codes:

1. Create a class name Server.java and paste the below code:

//Professional Cipher (www.professionalcipher.com)
import java.io.*;
import java.net.*;
import java.util.*;

public class Server
 {
  boolean closed=false,inputFromAll=false;
  List<clientThread> t;          
  List<String> data; 

 Server()
 {
   t= new ArrayList<clientThread>();          
   data= new ArrayList<String>();
 }

  public static void main(String args[])
  {
      Socket clientSocket = null;
      ServerSocket serverSocket = null;
      int port_number=8989;

      Server ser=new Server();
 
      try {
        serverSocket = new ServerSocket(port_number);
        }
        catch (IOException e)
        {System.out.println(e);}
   
    while(!ser.closed)
                {
        try {
        clientSocket = serverSocket.accept();
                                clientThread th=new clientThread(ser,clientSocket);
                                (ser.t).add(th);
        System.out.println("\nNow Total clients are : "+(ser.t).size());
        (ser.data).add("NOT_SENT");
        th.start();
               }
               catch (IOException e) {}
    }

        try
       {
         serverSocket.close();
       }catch(Exception e1){}
   
}
}

 class clientThread extends Thread
 {
   
 DataInputStream is = null;
 String line;
 String destClient="";
 String name;
 PrintStream os = null;
 Socket clientSocket = null;      
 String clientIdentity;
 Server ser;

   public clientThread(Server ser,Socket clientSocket)
    {
       this.clientSocket=clientSocket;
       this.ser=ser;
    }


   public void run()
    {
    try
                {
           is = new DataInputStream(clientSocket.getInputStream());
           os = new PrintStream(clientSocket.getOutputStream());
           os.println("Enter your name.");
           name = is.readLine();
                       clientIdentity=name;
os.println("Welcome "+name+" to this 2 Phase Application.\nYou will receive a vote Request now...");
os.println("VOTE_REQUEST\nPlease enter COMMIT or ABORT to proceed : ");
           for(int i=0; i<(ser.t).size(); i++)
           {
                if((ser.t).get(i)!=this)
                                    {
                          ((ser.t).get(i)).os.println("---A new user "+name+" entered the Appilcation---");
                                     }
                       }

                 while (true)
                 {
                     line = is.readLine();

                     if(line.equalsIgnoreCase("ABORT"))
                      {
                             System.out.println("\nFrom '"+clientIdentity+"' : ABORT\n\nSince aborted we will not wait for inputs from other clients.");
                             System.out.println("\nAborted....");
                 for(int i=0; i<(ser.t).size(); i++)
                 {
                               ((ser.t).get(i)).os.println("GLOBAL_ABORT");
                               ((ser.t).get(i)).os.close();
                               ((ser.t).get(i)).is.close();
                              }

                        break;
                  }


               if(line.equalsIgnoreCase("COMMIT"))
              {
                 System.out.println("\nFrom '"+clientIdentity+"' : COMMIT");
                 if((ser.t).contains(this))
                   {
                      (ser.data).set((ser.t).indexOf(this), "COMMIT");
                       for(int j=0;j<(ser.data).size();j++)
                       {
                              if(!(((ser.data).get(j)).equalsIgnoreCase("NOT_SENT")))
                                 {
                                    ser.inputFromAll=true;
                                    continue;
         }
           else
        {
           ser.inputFromAll=false;
                                   System.out.println("\nWaiting for inputs from other clients.");
           break;
        }
          }

                         if(ser.inputFromAll)
                         {
                            System.out.println("\n\nCommited....");
            
                            for(int i=0; i<(ser.t).size(); i++)
                 {
                                  ((ser.t).get(i)).os.println("GLOBAL_COMMIT");
                                  ((ser.t).get(i)).os.close();
                                  ((ser.t).get(i)).is.close();
                               }
                            break;
                        }

                         }//if t.contains
                     }//commit

                 }//while
              ser.closed=true;
             clientSocket.close();

       }    catch(IOException e){};
    }
}



2. Create a class name Client.java and paste the below code:

//Professional Cipher (www.professionalcipher.com)

import java.io.*;
import java.net.*;

public class Client implements Runnable{
    static Socket clientSocket = null;
    static PrintStream os = null;
    static DataInputStream is = null;
    static BufferedReader inputLine = null;
    static boolean closed = false;


    public static void main(String[] args)
    {
     int port_number=8989;
     String host="localhost";

    try {
            clientSocket = new Socket(host, port_number);
            inputLine = new BufferedReader(new InputStreamReader(System.in));
            os = new PrintStream(clientSocket.getOutputStream());
            is = new DataInputStream(clientSocket.getInputStream());
            } catch (Exception e) {
            System.out.println("Exception occurred : "+e.getMessage());
                }

        if (clientSocket != null && os != null && is != null)
        {
           try
               {
                    new Thread(new Client()).start();
       
                      while (!closed)
                     {
                       os.println(inputLine.readLine());
                     }

         os.close();
         is.close();
         clientSocket.close();

              } catch (IOException e)
                  {
                System.err.println("IOException:  " + e);
                  }
       }
  }          
   
    public void run()
    {       
    String responseLine;
    try
                {
        while ((responseLine = is.readLine()) != null)
                        {
                     System.out.println("\n"+responseLine);
if (responseLine.equalsIgnoreCase("GLOBAL_COMMIT")==true || responseLine.equalsIgnoreCase("GLOBAL_ABORT")==true )
                                  {
                                     break;
                                  }
            }
                   closed=true;
    } catch (IOException e)
                       {
             System.err.println("IOException:  " + e);
           }
    }
}


CONSOLE OUTPUTS:
*************SERVER************
Now Total clients are : 1
Now Total clients are : 2
Now Total clients are : 3
From 'Client 1' : COMMIT
Waiting for inputs from other clients.
From 'Client 2' : COMMIT
Waiting for inputs from other clients.
From 'Client 3' : ABORT
Since aborted we will not wait for inputs from other clients.
Aborted....

************CLIENT 1************
Enter your name.
Client 1
Welcome Client 1 to this 2 Phase Application.
You will receive a vote Request now...
VOTE_REQUEST
Please enter COMMIT or ABORT to proceed : 
---A new user Client 2 entered the Appilcation---
---A new user Client 3 entered the Appilcation---
COMMIT
GLOBAL_ABORT

************CLIENT 2************
Enter your name.
Client 2
Welcome Client 2 to this 2 Phase Application.
You will receive a vote Request now...
VOTE_REQUEST
Please enter COMMIT or ABORT to proceed : 
---A new user Client 3 entered the Appilcation---
COMMIT
GLOBAL_ABORT

************CLIENT 3************
Enter your name.
Client 3
Welcome Client 3 to this 2 Phase Application.
You will receive a vote Request now...
VOTE_REQUEST
Please enter COMMIT or ABORT to proceed : ABORT