vedioplayer.java

J2ME程序设计实例教程的源码

import javax.microedition.media.*;
import javax.microedition.media.control.*;
import javax.microedition.media.protocol.*;
import javax.microedition.io.file.*;
import javax.microedition.io.*;
import java.io.*;

/**
 * 该类用于获取视频的播放内容，并且播放视频。
 */
public class VedioPlayer implements Runnable {
    private static final String MPEG_TYPE = "video/mpeg";
    
    private MobilPlayerMIDlet midlet;
    private VedioCanvas canvas;
    private Player player;
    private VolumeControl volumeControl;
    private String vedioFile;
    
    public VedioPlayer(MobilPlayerMIDlet midlet, VedioCanvas canvas) {
        this.midlet = midlet;
        this.canvas = canvas;
    }
    
    //初始化视频资源
    public void initVedioResource(String file) {
        vedioFile = file;
        Thread t = new Thread(this);
        t.start();
    }
    
    //
    public void run() {
        try {
            FileConnection fc = (FileConnection)Connector.open("file://" + vedioFile);
            InputStream is = fc.openInputStream();
            
            //创建播放器
            player = Manager.createPlayer(is, MPEG_TYPE);
            player.addPlayerListener(midlet);
            
            //传输数据
            player.realize();
            //获取播放视频的资源
            player.prefetch();
            
            //获取视频控制器
            VideoControl videoControl = (VideoControl)player.getControl("VideoControl");
            if(videoControl == null) {
                midlet.showAlert("视频播放错误！");
            }
            else {
                //获取声音控制器
                volumeControl = (VolumeControl)player.getControl("VolumeControl");
                
                System.out.println("volumeControl = " + volumeControl.getLevel());
                
                //初始化视频显示模式
                videoControl.initDisplayMode(VideoControl.USE_DIRECT_VIDEO, canvas);
                int x = (canvas.getWidth() - videoControl.getDisplayWidth())/2;
                int y = (canvas.getHeight() - videoControl.getDisplayHeight())/2;
                videoControl.setDisplayLocation(x, y);  //显示位置
                videoControl.setVisible(true);  //显示视频
                startPlayer();    //开始播放
            }
        }
        catch(IOException ioe) {
            midlet.showAlert("不能连接到文件\""+vedioFile+"\"！\n" + ioe);
            closePlayer();
        }
        catch(MediaException me) {
            midlet.showAlert("不能创建播放器！\n" + me);
            closePlayer();
        }
    }
    
    public void startPlayer() throws MediaException {
        if(player != null) {
            player.start();
        }
    }
    
    public void stopPlayer() throws MediaException {
        if(player != null) {
            player.stop();
        }
    }
    
    public void closePlayer() {
        if(player != null) {
            player.close();
        }
        player = null;
        volumeControl = null;
    }
    
    //改变音量，整数表示增大音量，负数表示减小音量
    public void changeVolume(int value) {
        if(volumeControl != null) {
            int val = volumeControl.getLevel() + value;
            if(val < 0) {
                volumeControl.setLevel(0);
            }
            else if(val > 80) { 
                //在模拟器中测试时，音量超过85就会抛出异常
                volumeControl.setLevel(80);
            }
            else {
                volumeControl.setLevel(val);
            }
        }
    }
}