如何从JMF中的类路径加载媒体资源

时间:2011-11-29 02:03:08

标签: java jar jmf

所以,我有一个Java应用程序,我想变成一个可执行jar。我在这个应用程序中使用JMF,我似乎无法使声音文件正常工作......

我使用

创建jar
jar cvfm jarname.jar manifest.txt *.class *.gif *.wav

因此,所有声音文件都放在jar中,在代码中,我正在使用

创建播放器
Player player = Manager.createPlayer(ClassName.class.getResource("song1.wav"));

jar在我的桌面上,当我尝试运行它时,会发生以下异常:

javax.media.NoPlayerException: Cannot find a Player for :jar:file:/C:/Users/Pojo/
Desktop/jarname.jar!/song1.wav

...它没有获得IOExceptions,所以它似乎至少可以找到文件本身。

另外,在我使用getResource之前,我曾经这样说过:

Player player = Manager.createPlayer(new File("song1.wav").toURL());

它播放得很好,所以我知道声音文件本身没有任何问题。

我尝试切换到此方法而不是File方法的原因是声音文件可以打包在jar本身内,而不必是目录中的兄弟节点。

3 个答案:

答案 0 :(得分:3)

这与生产代码相差甚远,但这似乎解决了任何运行时异常(虽然它实际上还没有连接起来播放任何内容):

import javax.media.Manager;
import javax.media.Player;
import javax.media.protocol.URLDataSource;

// ...

URL url = JmfTest.class.getResource("song1.wav");
System.out.println("url: " + url);
URLDataSource uds = new URLDataSource(url);
uds.connect();
Player player = Manager.createPlayer(uds);

答案 1 :(得分:2)

新解决方案:

首先,需要一个返回DataSource的自定义SourceStream类来实现Seekable

package com.ziesemer.test;

import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.net.JarURLConnection;
import java.net.URL;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

import javax.media.Duration;
import javax.media.MediaLocator;
import javax.media.Time;
import javax.media.protocol.ContentDescriptor;
import javax.media.protocol.PullDataSource;
import javax.media.protocol.PullSourceStream;
import javax.media.protocol.Seekable;

/**
 * @author Mark A. Ziesemer
 *  <a href="http://www.ziesemer.com.">&lt;www.ziesemer.com&gt;</a>
 */
public class JarDataSource extends PullDataSource{

    protected JarURLConnection conn;
    protected ContentDescriptor contentType;
    protected JarPullSourceStream[] sources;
    protected boolean connected;

    public JarDataSource(URL url) throws IOException{
        setLocator(new MediaLocator(url));
        connected = false;
    }

    @Override
    public PullSourceStream[] getStreams(){
        return sources;
    }

    @Override
    public void connect() throws IOException{
        conn = (JarURLConnection)getLocator().getURL().openConnection();
        conn.connect();
        connected = true;

        JarFile jf = conn.getJarFile();
        JarEntry je = jf.getJarEntry(conn.getEntryName());

        String mimeType = conn.getContentType();
        if(mimeType == null){
            mimeType = ContentDescriptor.CONTENT_UNKNOWN;
        }
        contentType = new ContentDescriptor(ContentDescriptor.mimeTypeToPackageName(mimeType));

        sources = new JarPullSourceStream[1];
        sources[0] = new JarPullSourceStream(jf, je, contentType);
    }

    @Override
    public String getContentType(){
        return contentType.getContentType();
    }

    @Override
    public void disconnect(){
        if(connected){
            try{
                sources[0].close();
            }catch(IOException e){
                e.printStackTrace();
            }
            connected = false;
        }
    }

    @Override
    public void start() throws IOException{
        // Nothing to do.
    }

    @Override
    public void stop() throws IOException{
        // Nothing to do.
    }

    @Override
    public Time getDuration(){
        return Duration.DURATION_UNKNOWN;
    }

    @Override
    public Object[] getControls(){
        return new Object[0];
    }

    @Override
    public Object getControl(String controlName){
        return null;
    }

    protected class JarPullSourceStream implements PullSourceStream, Seekable, Closeable{

        protected final JarFile jarFile;
        protected final JarEntry jarEntry;
        protected final ContentDescriptor type;

        protected InputStream stream;
        protected long position;

        public JarPullSourceStream(JarFile jarFile, JarEntry jarEntry, ContentDescriptor type) throws IOException{
            this.jarFile = jarFile;
            this.jarEntry = jarEntry;
            this.type = type;
            this.stream = jarFile.getInputStream(jarEntry);
        }

        @Override
        public ContentDescriptor getContentDescriptor(){
            return type;
        }

        @Override
        public long getContentLength(){
            return jarEntry.getSize();
        }

        @Override
        public boolean endOfStream(){
            return position < getContentLength();
        }

        @Override
        public Object[] getControls(){
            return new Object[0];
        }

        @Override
        public Object getControl(String controlType){
            return null;
        }

        @Override
        public boolean willReadBlock(){
            if(endOfStream()){
                return true;
            }
            try{
                return stream.available() == 0;
            }catch(IOException e){
                return true;
            }
        }

        @Override
        public int read(byte[] buffer, int offset, int length) throws IOException{
            int read = stream.read(buffer, offset, length);
            position += read;
            return read;
        }

        @Override
        public long seek(long where){
            try{
                if(where < position){
                    stream.close();
                    stream = jarFile.getInputStream(jarEntry);
                    position = 0;
                }
                long skip = where - position;
                while(skip > 0){
                    long skipped = stream.skip(skip);
                    skip -= skipped;
                    position += skipped;
                }
            }catch(IOException ioe){
                // Made a best effort.
                ioe.printStackTrace();
            }
            return position;
        }

        @Override
        public long tell(){
            return position;
        }

        @Override
        public boolean isRandomAccess(){
            return true;
        }

        @Override
        public void close() throws IOException{
            try{
                stream.close();
            }finally{
                jarFile.close();
            }
        }

    }

}

然后,上面的自定义数据源用于创建播放器,并添加ControllerListener以使播放器循环:

package com.ziesemer.test;

import java.net.URL;

import javax.media.ControllerEvent;
import javax.media.ControllerListener;
import javax.media.EndOfMediaEvent;
import javax.media.Manager;
import javax.media.Player;
import javax.media.Time;

/**
 * @author Mark A. Ziesemer
 *  <a href="http://www.ziesemer.com.">&lt;www.ziesemer.com&gt;</a>
 */
public class JmfTest{
    public static void main(String[] args) throws Exception{
        URL url = JmfTest.class.getResource("Test.wav");
        JarDataSource jds = new JarDataSource(url);
        jds.connect();
        final Player player = Manager.createPlayer(jds);

        player.addControllerListener(new ControllerListener(){
            @Override
            public void controllerUpdate(ControllerEvent ce){
                if(ce instanceof EndOfMediaEvent){
                    player.setMediaTime(new Time(0));
                    player.start();
                }
            }
        });
        player.start();
    }
}

请注意,如果没有自定义数据源,JMF会反复尝试回头 - 但会失败,并最终放弃。这可以通过调试相同的ControllerListener来看出,每次尝试都会收到几个事件。

或者,使用MediaPlayer方法循环(您在我之前的回答中提到过):

package com.ziesemer.test;

import java.net.URL;

import javax.media.Manager;
import javax.media.Player;
import javax.media.bean.playerbean.MediaPlayer;

/**
 * @author Mark A. Ziesemer
 *  <a href="http://www.ziesemer.com.">&lt;www.ziesemer.com&gt;</a>
 */
public class JmfTest{
    public static void main(String[] args) throws Exception{
        URL url = JmfTest.class.getResource("Test.wav");
        JarDataSource jds = new JarDataSource(url);
        jds.connect();
        final Player player = Manager.createPlayer(jds);

        MediaPlayer mp = new MediaPlayer();
        mp.setPlayer(player);
        mp.setPlaybackLoop(true);
        mp.start();
    }
}

同样,我不会考虑这个生产就绪的代码(可以使用更多的Javadoc和日志记录等),但它经过测试和运行(Java 1.6),并且应该很好地满足您的需求。

圣诞快乐,节日快乐!

答案 2 :(得分:0)

Manager.createPlayer(this.getClass().getResource("/song1.wav"));

如果song1.wav位于应用程序的运行时类路径上的Jar的根目录中,那么这将有效。