statehelper.java

一些基本的代码,还有一些事例.值得一看

package jsounddemo2;


import javax.media.ControllerListener;
import javax.media.ControllerEvent;

import javax.media.*;
import javax.media.control.*;
import javax.media.datasink.*;
import javax.media.format.*;
import javax.media.protocol.*;

public class StateHelper implements ControllerListener {


  Player player = null;

  boolean configured = false;
  boolean realized = false;
  boolean prefetched = false;
  boolean failed = false;
  boolean closed = false;



  public StateHelper(Player player) {

    this.player=player;
    this.player.addControllerListener(this);
  }

  public boolean configure(int timeOutMillis){
    long startTime = System.currentTimeMillis();

    synchronized(this){
      if (player instanceof Processor){
        ((Processor)player).configure();
      }else{
        return false;
      }

      while (!configured && !failed){
        try{
          wait(timeOutMillis);
        }catch(InterruptedException err){

        }
        if (System.currentTimeMillis()-startTime>timeOutMillis)
          break;
      }
    }
    return this.configured;
  }


  public boolean realize(int timeOutMillis){
    long startTime = System.currentTimeMillis();
    synchronized(this){

      player.realize();
      while(!realized && !failed){
        try{
          wait(timeOutMillis);
        }catch(InterruptedException err){

        }
        if (System.currentTimeMillis()-startTime>timeOutMillis)
          break;

      }
    }

    return this.realized;
  }

  public boolean prefetch(int timeOutMillis){
    long startTime = System.currentTimeMillis();

    synchronized(this){
      player.prefetch();
      while( !prefetched && !failed){
        try{

          wait(timeOutMillis);
        }catch(InterruptedException err){

        }
        if (System.currentTimeMillis()-startTime>timeOutMillis)
          break;

      }
    }
    return this.prefetched;
  }

  public void close(){
    synchronized(this){
      player.close();
      while (!closed){
        try{
          wait(200);

        }catch(InterruptedException err){

        }

      }
    }
    player.removeControllerListener(this);
  }


  public void controllerUpdate(ControllerEvent parm1) {
    /**@todo Implement this javax.media.ControllerListener method*/
    //throw new java.lang.UnsupportedOperationException("Method controllerUpdate() not yet implemented.");
    if (parm1 instanceof RealizeCompleteEvent)
      this.realized = true;
    else
      if (parm1 instanceof ConfigureCompleteEvent)
        this.configured = true;
      else
        if (parm1 instanceof PrefetchCompleteEvent)
          this.prefetched = true;
        else
          if (parm1 instanceof ControllerErrorEvent)
            this.failed = true;
          else
            if (parm1 instanceof ControllerClosedEvent)
              this.closed = true;
            else
              return;

    notifyAll();



  }
}