Java 下進行多媒體播放器的開發十分簡單，有著很多成熟的擴充套件類包和相關開源播放器支援，本文將將介紹4類常見的 Java 多媒體框架。

No.1 JMF 與 FMJ

一、簡介

        JMF：The Java Media Framework API (JMF) enables audio, video and other time-based media to be added to applications and applets built on Java technology. This optional package, which can capture, playback, stream, and transcode multiple media formats, extends the Java 2 Platform, Standard Edition (J2SE) for multimedia developers by providing a powerful toolkit to develop scalable, cross-platform technology.

        FMJ：FMJ is an open-source project with the goal of providing an alternative to Java Media Framework (JMF), while remaining API-compatible with JMF. It aims to produce a single API/Framework which can be used to capture, playback, process, and stream media across multiple platforms. 

二、示例

/*
 * @(#)SimplePlayerApplet.java  1.2 01/03/13 //Sun公司給出的簡單視訊播放器程式碼，由於jmf支援格式有限，建議使用mpg格式檔案測試。

 *
 * Copyright (c) 1996-2001 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

import java.applet.Applet;
import java.awt.*;
import java.awt.event.*;
import java.lang.String;
import java.net.URL;
import java.net.MalformedURLException;
import java.io.IOException;
import java.util.Properties;
import javax.media.*;
//import com.sun.media.util.JMFSecurity;

/**
  * This is a Java Applet that demonstrates how to create a simple
  * media player with a media event listener. It will play the
  * media clip right away and continuously loop.
  * 
  *<!-- Sample HTML
  * <applet code=SimplePlayerApplet width=320 height=300>
  * <param name=file value="sun.avi">
  * </applet>
  * --> 
  */
public class SimplePlayerApplet extends Applet implements ControllerListener {
    
    // media Player
    Player player = null;
    // component in which video is playing
    Component visualComponent = null;
    // controls gain, position, start, stop
    Component controlComponent = null;
    // displays progress during download
    Component progressBar = null;
    boolean firstTime = true;
    long CachingSize = 0L;    
    Panel panel = null;
    int controlPanelHeight = 0;
    int videoWidth = 0;
    int videoHeight = 0;

    /**
     * Read the applet file parameter and create the media 
     * player.
     */
    public void init() {
        //$ System.out.println("Applet.init() is called");
        setLayout(null);
        setBackground(Color.white);
        panel = new Panel();
        panel.setLayout( null );
        add(panel);
        panel.setBounds(0, 0, 320, 240);

        // input file name from html param
        String mediaFile = null;
        // URL for our media file
        MediaLocator mrl = null;
        URL url = null;

        // Get the media filename info.
        // The applet tag should contain the path to the
        // source media file, relative to the html page.
        
        if ((mediaFile = getParameter("FILE")) == null)
            Fatal("Invalid media file parameter");

        try {
            url = new URL(getDocumentBase(), mediaFile);
            mediaFile = url.toExternalForm();
        } catch (MalformedURLException mue) {
        }
        
        try {
            // Create a media locator from the file name
            if ((mrl = new MediaLocator(mediaFile)) == null)
                Fatal("Can't build URL for " + mediaFile);

            /*
            try {
                JMFSecurity.enablePrivilege.invoke(JMFSecurity.privilegeManager,
                                                   JMFSecurity.writePropArgs);
                JMFSecurity.enablePrivilege.invoke(JMFSecurity.privilegeManager,
                                                   JMFSecurity.readPropArgs);
                JMFSecurity.enablePrivilege.invoke(JMFSecurity.privilegeManager,
                                                   JMFSecurity.connectArgs);
            } catch (Exception e) {}
            */
            
            // Create an instance of a player for this media
            try {
                player = Manager.createPlayer(mrl);
            } catch (NoPlayerException e) {
                System.out.println(e);
                Fatal("Could not create player for " + mrl);
            }

            // Add ourselves as a listener for a player's events
            player.addControllerListener(this);

        } catch (MalformedURLException e) {
            Fatal("Invalid media file URL!");
        } catch (IOException e) {
            Fatal("IO exception creating player for " + mrl);
        }

        // This applet assumes that its start() calls 
        // player.start(). This causes the player to become
        // realized. Once realized, the applet will get
        // the visual and control panel components and add
        // them to the Applet. These components are not added
        // during init() because they are long operations that
        // would make us appear unresposive to the user.
    }

    /**
     * Start media file playback. This function is called the
     * first time that the Applet runs and every
     * time the user re-enters the page.
     */

    public void start() {
        //$ System.out.println("Applet.start() is called");
        // Call start() to prefetch and start the player.
        if (player != null)
            player.start();
    }

    /**
     * Stop media file playback and release resource before
     * leaving the page.
     */
    public void stop() {
        //$ System.out.println("Applet.stop() is called");
        if (player != null) {
            player.stop();
            player.deallocate();
        }
    }

    public void destroy() {
        //$ System.out.println("Applet.destroy() is called");
        player.close();
    }


    /**
     * This controllerUpdate function must be defined in order to
     * implement a ControllerListener interface. This 
     * function will be called whenever there is a media event
     */
    public synchronized void controllerUpdate(ControllerEvent event) {
        // If we're getting messages from a dead player, 
        // just leave
        if (player == null)
            return;
        
        // When the player is Realized, get the visual 
        // and control components and add them to the Applet
        if (event instanceof RealizeCompleteEvent) {
            if (progressBar != null) {
                panel.remove(progressBar);
                progressBar = null;
            }

            int width = 320;
            int height = 0;
            if (controlComponent == null)
                if (( controlComponent = 
                      player.getControlPanelComponent()) != null) {
                    
                    controlPanelHeight = controlComponent.getPreferredSize().height;
                    panel.add(controlComponent);
                    height += controlPanelHeight;
                }
            if (visualComponent == null)
                if (( visualComponent =
                      player.getVisualComponent())!= null) {
                    panel.add(visualComponent);
                    Dimension videoSize = visualComponent.getPreferredSize();
                    videoWidth = videoSize.width;
                    videoHeight = videoSize.height;
                    width = videoWidth;
                    height += videoHeight;
                    visualComponent.setBounds(0, 0, videoWidth, videoHeight);
                }

            panel.setBounds(0, 0, width, height);
            if (controlComponent != null) {
                controlComponent.setBounds(0, videoHeight,
                                           width, controlPanelHeight);
                controlComponent.invalidate();
            }
            
        } else if (event instanceof CachingControlEvent) {
            if (player.getState() > Controller.Realizing)
                return;
            // Put a progress bar up when downloading starts, 
            // take it down when downloading ends.
            CachingControlEvent e = (CachingControlEvent) event;
            CachingControl cc = e.getCachingControl();

            // Add the bar if not already there ...
            if (progressBar == null) {
                if ((progressBar = cc.getControlComponent()) != null) {
                    panel.add(progressBar);
                    panel.setSize(progressBar.getPreferredSize());
                    validate();
                }
            }
        } else if (event instanceof EndOfMediaEvent) {
            // We've reached the end of the media; rewind and
            // start over
            player.setMediaTime(new Time(0));
            player.start();
        } else if (event instanceof ControllerErrorEvent) {
            // Tell TypicalPlayerApplet.start() to call it a day
            player = null;
            Fatal(((ControllerErrorEvent)event).getMessage());
        } else if (event instanceof ControllerClosedEvent) {
            panel.removeAll();
        }
    }

    void Fatal (String s) {
        // Applications will make various choices about what
        // to do here. We print a message
        System.err.println("FATAL ERROR: " + s);
        throw new Error(s); // Invoke the uncaught exception
                            // handler System.exit() is another
                            // choice.
        
    }
}
 

FMJ本人沒用過，而且個人認為意義也不大，就不貼程式碼了。

三、評價

        JMF 算是 Java 平臺上最早的多媒體綜合解決方案了（ Sun 公司官方出品），不過由於種種原因 JMF 早已不再更新（最新版本為2.1.1e，可以再 Oracle 官網免費獲得），導致無論是格式支援還是功能擴充套件如今都很難再滿足我們的開發需求了，雖然各種 Java 教程倒是喜歡那它作為教學案例。而後出現的 FMJ 從名字就可以看出和 JMF 有很大關係，目標是扛過 JMF 的大旗。這裡特別注意的是，它的發展思路對之後的 Java 多媒體框架開發有著重要的啟示作用，其核心思想是利用 FFMPEG 等專業的多媒體解碼器提供 Java 擴充套件介面，不過據說（我也沒用過）實際效果不是很好，現在已經很少有人用了。總之，JMF 和 FMJ 如今只能算是 Java 多媒體開發歷史上的里程牌，實際用處不多。