package test.lang;
import org.apache.log4j.Category;
 
public class Blocking
{
  public static final String MESSAGE 
    = "This is the message to access in the Blocking call";
    
  public static final int MAX_TIME = 2500;
    
  Category log;
  
  public Blocking()
  {
    log = Category.getInstance (Blocking.class);
  }
 
  public String call (int aDelay)
  {
    log.info ("Blocking call");
    try
    {
      Thread.sleep (aDelay);
    }catch (Exception e)
    {
      log.warn ("Thread was Interrupted");
    
    }
    return MESSAGE;
  }
  
  public String call ()
  {
    return this.call (MAX_TIME);
  }  
}

package test.lang;
 
public class BlockingThread
  extends Thread
{
  public Blocking blk = null;
  public Object returnedValue = null;
  
  BlockingThread ()
  {
    blk = new Blocking ();
  }
  
  public void run ()
  {
    returnedValue = blk.call ();
  }
 
  public Object getValue()
  {
    return returnedValue;
  }  
}

/**
  * Who ever wants to use this code could allegdly place the following 
  * line :
  *       Based upon an idea of Duffy JohnJ
  *       
  *   as posted on yahoogroups Advanced Java mailing list 
  *   SomeType callBlockingMethod(Blocking obj, long timeout) 
  *   {
  *     Thread t = new BlockingThread(obj);
  *     t.start();
  *     t.join(timeout);
  *     if (t.isAlive()) 
  *     {
  *        return null;
  *     } else 
  *     {
  *        return t.someValue();
  *     }
  *   }
  *
  */
package test.lang;
 
import org.apache.log4j.Category;
import org.apache.log4j.BasicConfigurator;
 
 
public class NonBlockingWrapper
{
  public Object callBlockingMethod(long timeout) 
  {
    BlockingThread t = new BlockingThread();
    t.start();
    Thread.currentThread ().yield ();
    try 
    {
      t.join(timeout);
    }
    catch (Exception ex) 
    {
      System.out.print ("Exception thrown");
    }
    
    if (t.isAlive()) 
    {
      return null;
    } else 
    {
      return t.getValue ();
    }
  }
 
/** 
  *
  */
  public static void main (String[] args)
  {
    BasicConfigurator.resetConfiguration ();
    BasicConfigurator.configure ();
    NonBlockingWrapper NBW = new NonBlockingWrapper();
    System.out.println ("Response is " + NBW.callBlockingMethod (3500));
  }
}