Jlayer MP3 Player，Java中mp3文件的控制音量

Question

I need to know what should i use for controlling volume in MP3 player which I've created using jLayer? Which API or Methods I can use to control volume of mp3 file ?

Answer 1

  public class VolumeSlider{
 // to get the aydiosystem gain control
     public void setGain(float ctrl)  
    {          
        try {  
        Mixer.Info[] infos = AudioSystem.getMixerInfo();    
        for (Mixer.Info info: infos)    
        {    
           Mixer mixer = AudioSystem.getMixer(info);  
           if (mixer.isLineSupported(Port.Info.SPEAKER))    
           {    
              Port port = (Port)mixer.getLine(Port.Info.SPEAKER);    
              port.open();    
              if (port.isControlSupported(FloatControl.Type.VOLUME))    
              {    
                 FloatControl volume =  (FloatControl)port.getControl(FloatControl.Type.VOLUME);                    
                 volume.setValue(ctrl);  
              }    
              port.close();    
           }    
         }    
        } catch (Exception e) {   
            JOptionPane.showMessageDialog(null,"Erro\n"+e);  
        }  
    }