教你如何使用javax.sound.midi包

package lookbook.midi;
import javax.sound.midi.*;
import java.io.*;
import java.net.*;
/**
* Title:
* Description: how to use java midi from javax.sound.midi's Package
* Copyright: Copyright (c) 2003
* Company:
* @author lookbook
* @version 1.0
*/
public class MidiMain {
private static String midiFile = "town.mid";
private static String midiURI = "http://hostname/midifile";
private Sequence sequence =null;
public MidiMain() {
this.loadAndPlay();
}
public void loadAndPlay(){
try {
// From file
sequence = MidiSystem.getSequence(new File(midiFile));
// From URL
// sequence = MidiSystem.getSequence(new URL("http://hostname/midifile"));
// Create a sequencer for the sequence
Sequencer sequencer = MidiSystem.getSequencer();
sequencer.open();
sequencer.setSequence(sequence);
//Determining the Duration of a Midi Audio File
double durationInSecs = sequencer.getMicrosecondLength() / 1000000.0;
System.out.println("the duration of this audio is "+durationInSecs+"secs.");
//Determining the Position of a Midi Sequencer
double seconds = sequencer.getMicrosecondPosition() / 1000000.0;
System.out.println("the Position of this audio is "+seconds+"secs.");
//Setting the Volume of Playing Midi Audio
if (sequencer instanceof Synthesizer) {
Synthesizer synthesizer = (Synthesizer)sequencer;
MidiChannel[] channels = synthesizer.getChannels();
// gain is a value between 0 and 1 (loudest)
double gain = 0.9D;
for (int i=0; i<channels.length; i++) {
channels[i].controlChange(7, (int)(gain * 127.0));
}
}
// Start playing
sequencer.start();
//Determining the Position of a Midi Sequencer
Thread.currentThread().sleep(5000);
seconds = sequencer.getMicrosecondPosition() / 1000000.0;
System.out.println("the Position of this audio is "+seconds+"secs.");
//Add a listener for meta message events
sequencer.addMetaEventListener(
new MetaEventListener() {
public void meta(MetaMessage event) {
// Sequencer is done playing
if (event.getType() == 47) {
System.out.println("Sequencer is done playing.");
}
}
});
}catch (MalformedURLException e) {
}catch (IOException e) {
}catch (MidiUnavailableException e) {
}catch (InvalidMidiDataException e) {
}catch (InterruptedException e){
}
}
public static void main(String[] args) {
MidiMain midi = new MidiMain();
}
}