import java.io.*;
import java.util.*;

import java.sql.*;
import javax.sql.*;
import oracle.jdbc.xa.OracleXid;
import oracle.jdbc.xa.client.*;
import javax.transaction.xa.*;

public class DistributedTransaction {

  public static Xid createXid (int p_bID) throws XAException {
    byte[] l_gID = new byte[1];  // Global ID
    l_gID[0]     = (byte) 9;     // Set Global Id to 9
    byte[] l_bID = new byte[1];  // Branch ID
    l_bID[0]     = (byte) p_bID; // Set branch ID to the parameter passed

    byte[] l_globalID = new byte[64];
    byte[] l_branchID = new byte[64];

    // Copy the Global ID and branch ID to a 64 bit string
    System.arraycopy (l_gID, 0, l_globalID, 0, 1);
    System.arraycopy (l_bID, 0, l_branchID, 0, 1);
    // Call OracleXid() to generate the Xid
    Xid l_xid = new OracleXid(0x1234, l_globalID, l_branchID);
    // Return the Transaction ID
    return l_xid;
  }

  public static void main (String args[]) throws SQLException {
    OracleXADataSource ds1 = new OracleXADataSource ();
    OracleXADataSource ds2 = new OracleXADataSource ();
    ds1.setURL ("jdbc:oracle:thin:@antarctica:1521:mydb");
    ds2.setURL ("jdbc:oracle:thin:@arctic:1521:yourdb");

    // Verbindung mit Hilfe des Connection-Pools aufbauen
    XAConnection xacon1 = ds1.getXAConnection ("tux", "pingus");
    XAConnection xacon2 = ds2.getXAConnection ("tux", "pingus");

    Connection c1 = xacon1.getConnection ();
    Connection c2 = xacon2.getConnection ();
 
    // Transaktionsressourcen ermittlen
    XAResource xares1 = xacon1.getXAResource ();
    XAResource xares2 = xacon2.getXAResource ();

    // globale Transaktions-ID erzeugen
    Xid xid1 = createXid (1);
    Xid xid2 = createXid (2);

    // ... und starten
    xares1.start (xid1, XAResource.TMNOFLAGS);
    xares2.start (xid2, XAResource.TMNOFLAGS); 

    // Statement erzeugen
    String updStmt =
      "UPDATE book SET price = price * 0.9";
    Statement stmt1 = c1.createStatement ();
    Statement stmt2 = c2.createStatement ();

    // ... und ausführen
    stmt1.executeUpdate (updStmt);
    stmt2.executeUpdate (updStmt);

    // Suspend
    xares1.end (xid1, XAResource.TMSUCCESS);
    xares2.end (xid2, XAResource.TMSUCCESS);
 
    // Transaktionen auf Commit vorbereiten 
    int prep1 = xares1.prepare (xid1);
    int prep2 = xares2.prepare (xid2);
    if (prep1 == XAResource.XA_OK && prep2 == XAResource.XA_OK) {
	// Commit durchführen
      xares1.commit (xid1, false);
      xares2.commit (xid2, false);
    }
    else {
	// Transaktionen zurücksetzen
      xares1.rollback (xid1);
      xares2.rollback (xid2);
    }           
  }
}