Java Sound为各种声线功能提供了FloatControl个实例，MASTER_GAIN和{ VOLUME控制类型。
这些控件可用于更改系统音量吗？
答案 0 :(得分：11)
不，它不能。以下是源代码改为Adjusting master volume的答案。源迭代可用行，检查它们是否具有正确类型的控件，如果是，则将它们放在附加到JSlider
import java.awt.*;
import javax.swing.*;
import javax.sound.sampled.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class SoundMixer {
public Component getGui() {
JPanel gui = new JPanel(new GridLayout(0,1));
Mixer.Info[] mixers = AudioSystem.getMixerInfo();
System.out.println(
"There are " + mixers.length + " mixer info objects");
for (Mixer.Info mixerInfo : mixers) {
System.out.println("mixer name: " + mixerInfo.getName());
Mixer mixer = AudioSystem.getMixer(mixerInfo);
Line.Info[] lineInfos = mixer.getSourceLineInfo();
for (Line.Info lineInfo : lineInfos) {
System.out.println(" Line.Info: " + lineInfo);
try {
Line line = mixer.getLine(lineInfo);
FloatControl volCtrl = (FloatControl)line.getControl(
FloatControl.Type.MASTER_GAIN);
VolumeSlider vs = new VolumeSlider(volCtrl);
gui.add( new JLabel(volCtrl.toString()) );
gui.add( vs.getVolume() );
System.out.println(
" volCtrl.getValue() = " + volCtrl.getValue());
} catch (LineUnavailableException e) {
e.printStackTrace();
} catch (IllegalArgumentException iaEx) {
System.out.println(" " + iaEx);
}
}
}
return gui;
}
public static void main(String[] args) {
Runnable r = new Runnable() {
@Override
public void run() {
SoundMixer sm = new SoundMixer();
Component c = sm.getGui();
JOptionPane.showMessageDialog(null, c);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
SwingUtilities.invokeLater(r);
}
}
class VolumeSlider {
JSlider volume;
VolumeSlider(final FloatControl volumeControl) {
volume = new JSlider(
(int) volumeControl.getMinimum() * 100,
(int) volumeControl.getMaximum() * 100,
(int) volumeControl.getValue() * 100);
ChangeListener listener = new ChangeListener() {
@Override
public void stateChanged(ChangeEvent e) {
float val = volume.getValue() / 100f;
volumeControl.setValue(val);
System.out.println(
"Setting volume of " + volumeControl.toString() +
" to " + val);
}
};
volume.addChangeListener(listener);
}
public JSlider getVolume() {
return volume;
}
}
在这台Windows 7机器上，我从“Java Sound Audio Engine”获得两个控件。对当前的系统容量都没有任何影响。
run:
There are 4 mixer info objects
mixer name: Primary Sound Driver
Line.Info: interface SourceDataLine supporting 8 audio formats, and buffers of at least 32 bytes
java.lang.IllegalArgumentException: Unsupported control type: Master Gain
Line.Info: interface Clip supporting 8 audio formats, and buffers of at least 32 bytes
java.lang.IllegalArgumentException: Unsupported control type: Master Gain
mixer name: Speakers (VIA High Definition Audio)
Line.Info: interface SourceDataLine supporting 8 audio formats, and buffers of at least 32 bytes
java.lang.IllegalArgumentException: Unsupported control type: Master Gain
Line.Info: interface Clip supporting 8 audio formats, and buffers of at least 32 bytes
java.lang.IllegalArgumentException: Unsupported control type: Master Gain
mixer name: Java Sound Audio Engine
Line.Info: interface SourceDataLine supporting 8 audio formats
volCtrl.getValue() = 0.0
Line.Info: interface Clip supporting 8 audio formats, and buffers of 0 to 4194304 bytes
volCtrl.getValue() = 0.0
mixer name: Port Speakers (VIA High Definition A
Setting volume of Master Gain with current value: 0.0 dB (range: -80.0 - 13.9794) to 0.0
Setting volume of Master Gain with current value: 0.0 dB (range: -80.0 - 13.9794) to -0.41
Setting volume of Master Gain with current value: 0.0 dB (range: -80.0 - 13.9794) to -0.68
...
为FloatControl.Type.MASTER_GAIN交换FloatControl.Type.VOLUME以查看..无控件。
答案 1 :(得分：1)
在初始化Line之后添加以下行。这是打开线路所必需的。
boolean opened = line.isOpen() || line instanceof Clip;
if(!opened){
System.out.println("Line is not open, trying to open it...");
line.open();
opened = true;
}
答案 2 :(得分：0)
试试这个它不会让你失望....我们可以相应地修改上面的例子。
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.FloatControl;
import javax.sound.sampled.Line;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.Mixer;
import javax.swing.BoxLayout;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JProgressBar;
public class SoundMeter {
JFrame j;
public SoundMeter() {
j = new JFrame("SoundMeter");
j.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
j.setLayout(new BoxLayout(j.getContentPane(), BoxLayout.Y_AXIS));
printMixersDetails();
j.setVisible(true);
}
public void printMixersDetails(){
javax.sound.sampled.Mixer.Info[] mixers = AudioSystem.getMixerInfo();
System.out.println("There are " + mixers.length + " mixer info objects");
for(int i=0;i<mixers.length;i++){
Mixer.Info mixerInfo = mixers[i];
System.out.println("Mixer Name:"+mixerInfo.getName());
Mixer mixer = AudioSystem.getMixer(mixerInfo);
Line.Info[] lineinfos = mixer.getTargetLineInfo();
for(Line.Info lineinfo : lineinfos){
System.out.println("line:" + lineinfo);
try {
Line line = mixer.getLine(lineinfo);
line.open();
if(line.isControlSupported(FloatControl.Type.VOLUME)){
FloatControl control = (FloatControl) line.getControl(FloatControl.Type.VOLUME);
System.out.println("Volume:"+control.getValue());
JProgressBar pb = new JProgressBar();
// if you want to set the value for the volume 0.5 will be 50%
// 0.0 being 0%
// 1.0 being 100%
control.setValue((float) 0.5);
int value = (int) (control.getValue()*100);
pb.setValue(value);
j.add(new JLabel(lineinfo.toString()));
j.add(pb);
j.pack();
}
} catch (LineUnavailableException e) {
e.printStackTrace();
}
}
}
}
public static void main(String[] args) {
new SoundMeter();
}
}
答案 3 :(得分：0)
我正在使用VOLUME控件类型。这段代码适用于XP和WIN 7，但不适用于OSX。看我的例子：
import java.io.IOException;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.FloatControl;
import javax.sound.sampled.Line;
import javax.sound.sampled.Mixer;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class VolumeExample extends JPanel {
/**
* @return main sound control object
* @throws Exception for any problem
*/
private FloatControl getVolumeControl() throws Exception {
try {
Mixer.Info mixers[] = AudioSystem.getMixerInfo();
for (Mixer.Info mixerInfo : mixers) {
Mixer mixer = AudioSystem.getMixer(mixerInfo);
mixer.open();
//we check only target type lines, because we are looking for "SPEAKER target port"
for (Line.Info info : mixer.getTargetLineInfo()) {
if (info.toString().contains("SPEAKER")) {
Line line = mixer.getLine(info);
try {
line.open();
} catch (IllegalArgumentException iae) {}
return (FloatControl) line.getControl(FloatControl.Type.VOLUME);
}
}
}
} catch (Exception ex) {
System.out.println("problem creating volume control object:"+ex);
throw ex;
}
throw new Exception("unknown problem creating volume control object");
}
VolumeExample() {
JSlider slider = new JSlider();
add(slider);
//this is for setting the value
slider.addChangeListener(new ChangeListener() {
@Override
public void stateChanged(ChangeEvent e) {
JSlider src = (JSlider)e.getSource();
//if (src.getValueIsAdjusting()) return; //optional
if (src.getValue() % 5 !=0) return;
float value = src.getValue() / 100.0f;
try {
getVolumeControl().setValue(value);
//you can put a click play code here to have nice feedback when moving slider
} catch (Exception ex) {
System.out.println(ex);
}
}
});
//and this is for getting the value
try {
slider.setValue((int) (getVolumeControl().getValue()*100.0f));
} catch (Exception e) {
System.out.println(e);
}
}
}
答案 4 :(得分：0)
我最近关注同样的问题。最后，我决定在C ++中编写一个名为VolumeChanger.exe的程序，并从java中调用它。效果很好。您可以使用
从java调用exe Process process = new ProcessBuilder(vcpath,"-u").start();
wehre vcpath是你的exe文件的路径（当然可以是实例）。
如果您对我使用此工具感兴趣，请访问muteFritz
如果您对整个源代码感兴趣，请随时PM我...
答案 5 :(得分：0)
这是一个仅适用于OS X的解决方案（我正在运行10.10）：
import java.io.BufferedReader;
import java.io.File;
import java.io.InputStreamReader;
public class MasterVolume
{
public void setMasterVolume(float value)
{
String command = "set volume " + value;
try
{
ProcessBuilder pb = new ProcessBuilder("osascript","-e",command);
pb.directory(new File("/usr/bin"));
System.out.println(command);
StringBuffer output = new StringBuffer();
Process p = pb.start();
p.waitFor();
BufferedReader reader =
new BufferedReader(new InputStreamReader(p.getInputStream()));
String line;
while ((line = reader.readLine())!= null)
{
output.append(line + "\n");
}
System.out.println(output);
}
catch(Exception e)
{
System.out.println(e);
}
}
}
你可以这样调用这个方法：
MasterVolume.setMasterVolume(3.5f);
由于范围为.1到7.0
，因此将音量设置为50％