具有端口和数据线的 JavaSound 混音器？

Question

JavaSound API 程序员指南中的图表似乎暗示(第 19-20 页)混合器原则上可以同时拥有数据线和端口。不过，我想知道是否有人真正见过这个配置？我看到的是，在相关的情况下，混合器成对出现，一个带有源/目标数据线，另一个带有相应的端口。

有没有人亲眼目睹过指南中暗示的配置，混音器同时具有端口和数据线(或者我是否误解了指南)？

Answer 1

我正在为我的网站开发此功能，网址为 pscode.org ，但还没有完全完成。无论如何，它都以小程序或应用程序的形式很好地概述了声音系统。

/*
<applet
    code='MediaTypes'
    width='800'
    height='600'>
<param name='show' value='Sound|Sampled|Mixers|Primary Sound Driver'>
</applet>
*/
import javax.imageio.ImageIO;
import javax.sound.sampled.*;
import javax.sound.midi.*;
import java.awt.*;
import java.util.Arrays;
import java.util.ArrayList;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import javax.swing.tree.*;
import javax.swing.event.*;
import javax.swing.text.Position;

public class MediaTypes extends JApplet {

    JTable table;
    boolean sortable = false;
    JTree tree;

    public void init() {
        Runnable r = new Runnable() {
            public void run() {
                MediaTypes mediaTypes = new MediaTypes();

                String show = "";
                if (getParameter("show")!=null) {
                    show = getParameter("show");
                }

                JPanel p = new JPanel();
                mediaTypes.createGui(p, show);
                add(p);
                validate();
            }
        };
        SwingUtilities.invokeLater(r);
    }

    public static void main(String[] args) {
        Runnable r = new Runnable() {
            public void run() {
                MediaTypes mediaTypes = new MediaTypes();

                JPanel p = new JPanel();
                mediaTypes.createGui(p);
                JOptionPane.showMessageDialog(null,p);
            }
        };
        SwingUtilities.invokeLater(r);
    }

    public Object[][] mergeArrays(String name1, Object[] data1, String name2, Object[] data2) {
        Object[][] data = new Object[data1.length+data2.length][2];
        for (int ii=0; ii<data1.length; ii++) {
            data[ii][0] = name1;
            data[ii][1] = data1[ii];
        }
        int offset = data1.length;
        for (int ii=offset; ii<data.length; ii++) {
            data[ii][0] = name2;
            data[ii][1] = data2[ii-offset];
        }
        return data;
    }

    public void createGui(JPanel panel) {
        createGui(panel, "");
    }

    public String getShortLineName(String name) {
        String[] lineTypes = {
            "Clip",
            "SourceDataLine",
            "TargetDataLine",
            "Speaker",
            "Microphone",
            "Master Volume",
            "Line In"
        };
        for (String shortName : lineTypes) {
            if ( name.toLowerCase().replaceAll("_", " ").contains(shortName.toLowerCase() )) {
                return shortName;
            }
        }
        return name;
    }

    public void createGui(JPanel panel, String path) {

        //DefaultMutableTreeNode selected = null;

        panel.setLayout( new BorderLayout(5,5) );
        final JLabel output = new JLabel("Select a tree leaf to see the details.");
        panel.add(output, BorderLayout.SOUTH);

        table = new JTable();
        try {
            table.setAutoCreateRowSorter(true);
            sortable = true;
        } catch (Throwable ignore) {
            // 1.6+ functionality - not vital
        }
        JScrollPane tableScroll = new JScrollPane(table);
        Dimension d = tableScroll.getPreferredSize();
        d = new Dimension(450,d.height);
        tableScroll.setPreferredSize(d);
        panel.add( tableScroll, BorderLayout.CENTER );

        DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode("Media");
        DefaultTreeModel treeModel = new DefaultTreeModel(rootNode);

        DefaultMutableTreeNode imageNode = new DefaultMutableTreeNode("Image");
        rootNode.add(imageNode);

        Object[][] data;
        int offset;
        String[] columnNames;

        data = mergeArrays(
            "Reader",
            ImageIO.getReaderFileSuffixes(),
            "Writer",
            ImageIO.getWriterFileSuffixes() );
        columnNames = new String[]{"Input/Output", "Image File Suffixes"};
        MediaData md = new MediaData( "Suffixes", columnNames, data);
        imageNode.add(new DefaultMutableTreeNode(md));

        data = mergeArrays(
            "Reader",
            ImageIO.getReaderMIMETypes(),
            "Writer",
            ImageIO.getWriterMIMETypes() );
        columnNames = new String[]{"Input/Output", "Image MIME Types"};
        md = new MediaData( "MIME", columnNames, data);
        imageNode.add(new DefaultMutableTreeNode(md));

        DefaultMutableTreeNode soundNode = new DefaultMutableTreeNode("Sound");
        rootNode.add(soundNode);

        DefaultMutableTreeNode soundSampledNode = new DefaultMutableTreeNode("Sampled");
        soundNode.add(soundSampledNode);

        md = new MediaData("Suffixes", "Sound File Suffixes", AudioSystem.getAudioFileTypes());
        soundSampledNode.add(new DefaultMutableTreeNode(md));

        Mixer.Info[] mixerInfo = AudioSystem.getMixerInfo();
        String[][] mixerData = new String[mixerInfo.length][4];
        for (int ii=0; ii<mixerData.length; ii++) {
            mixerData[ii][0] = mixerInfo[ii].getName();
            mixerData[ii][1] = mixerInfo[ii].getVendor();
            mixerData[ii][2] = mixerInfo[ii].getVersion();
            mixerData[ii][3] = mixerInfo[ii].getDescription();
        }
        columnNames = new String[]{"Name", "Vendor", "Version", "Description"};
        md = new MediaData("Mixers", columnNames, mixerData);
        DefaultMutableTreeNode soundSampledMixersNode = new DefaultMutableTreeNode(md);
        soundSampledNode.add(soundSampledMixersNode);

        for (int ii=0; ii<mixerInfo.length; ii++) {
            Mixer mixer = AudioSystem.getMixer(mixerInfo[ii]);
            data = mergeArrays(
                "Source",
                mixer.getSourceLineInfo(),
                "Target",
                mixer.getTargetLineInfo() );
            columnNames = new String[]{ "Input/Output", "Line Info" };
            md = new MediaData(mixerInfo[ii].getName(), columnNames, data);
            DefaultMutableTreeNode soundSampledMixerNode = new DefaultMutableTreeNode(md);
            soundSampledMixersNode.add( soundSampledMixerNode );

            //Mixer mixer = AudioSystem.getMixer(mixerInfo[ii]);
            Line.Info[] source = mixer.getSourceLineInfo();
            Line.Info[] target = mixer.getTargetLineInfo();
            Line[] all = new Line[source.length + target.length];
            try {
                for (int jj=0; jj<source.length; jj++) {
                    all[jj] = AudioSystem.getLine(source[jj]);
                }
                for (int jj=source.length; jj<all.length; jj++) {
                    all[jj] = AudioSystem.getLine(target[jj-source.length]);
                }
                columnNames = new String[]{"Attribute", "Value"};
                for (Line line : all) {
                    Control[] controls = line.getControls();
                    if (line instanceof DataLine) {
                        DataLine dataLine = (DataLine)line;
                        AudioFormat audioFormat = dataLine.getFormat();
                        data = new Object[7+controls.length][2];

                        data[0][0] = "Channels";
                        data[0][1] = new Integer(audioFormat.getChannels());

                        data[1][0] = "Encoding";
                        data[1][1] = audioFormat.getEncoding();

                        data[2][0] = "Frame Rate";
                        data[2][1] = new Float(audioFormat.getFrameRate());

                        data[3][0] = "Sample Rate";
                        data[3][1] = new Float(audioFormat.getSampleRate());

                        data[4][0] = "Sample Size (bits)";
                        data[4][1] = new Integer(audioFormat.getSampleSizeInBits());

                        data[5][0] = "Big Endian";
                        data[5][1] = new Boolean(audioFormat.isBigEndian());

                        data[6][0] = "Level";
                        data[6][1] = new Float(dataLine.getLevel());

                    } else if (line instanceof Port) {
                        Port port = (Port)line;
                        Port.Info portInfo = (Port.Info)port.getLineInfo();
                        data = new Object[2+controls.length][2];

                        data[0][0] = "Name";
                        data[0][1] = portInfo.getName();

                        data[1][0] = "Source";
                        data[1][1] = new Boolean(portInfo.isSource());
                    } else {
                        System.out.println( "?? " + line );
                    }
                    int start = data.length-controls.length;
                    for (int kk=start; kk<data.length; kk++) {
                        data[kk][0] = "Control";
                        int index = kk-start;
                        data[kk][1] = controls[index];
                    }
                    md = new MediaData(getShortLineName(line.getLineInfo().toString()), columnNames, data);
                    soundSampledMixerNode.add(new DefaultMutableTreeNode(md));
                }
            } catch(Exception e) {
                e.printStackTrace();
            }
        }

        int[] midiTypes = MidiSystem.getMidiFileTypes();
        data = new Object[midiTypes.length][2];
        for (int ii=0; ii<midiTypes.length; ii++) {
            data[ii][0] = new Integer(midiTypes[ii]);
            String description = "Unknown";
            switch (midiTypes[ii]) {
                case 0:
                    description = "Single Track";
                    break;
                case 1:
                    description = "Multi Track";
                    break;
                case 2:
                    description = "Multi Song";
            }
            data[ii][1] = description;
        }
        columnNames = new String[]{"Type", "Description"};
        md = new MediaData("MIDI", columnNames, data);
        DefaultMutableTreeNode soundMIDINode = new DefaultMutableTreeNode(md);
        soundNode.add(soundMIDINode);

        columnNames = new String[]{
            "Attribute",
            "Value"};
        MidiDevice.Info[] midiDeviceInfo = MidiSystem.getMidiDeviceInfo() ;
        for (int ii=0; ii<midiDeviceInfo.length; ii++) {
            data = new Object[6][2];
            data[0][0] = "Name";
            data[0][1] = midiDeviceInfo[ii].getName();

            data[1][0] = "Vendor";
            data[1][1] = midiDeviceInfo[ii].getVendor();

            data[2][0] = "Version";
            String version = midiDeviceInfo[ii].getVersion();
            data[2][1] = version.replaceAll("Version ", "");

            data[3][0] = "Description";
            data[3][1] = midiDeviceInfo[ii].getDescription();

            data[4][0] = "Maximum Transmitters";
            data[5][0] = "Maximum Receivers";
            try {
                MidiDevice midiDevice = MidiSystem.getMidiDevice(midiDeviceInfo[ii]);
                Object valueTransmitter;
                if (midiDevice.getMaxTransmitters()==AudioSystem.NOT_SPECIFIED) {
                    valueTransmitter = "Not specified";
                } else {
                    valueTransmitter = new Integer(midiDevice.getMaxTransmitters());
                }

                Object valueReceiver;
                if (midiDevice.getMaxReceivers()==AudioSystem.NOT_SPECIFIED) {
                    valueReceiver = "Not specified";
                } else {
                    valueReceiver = new Integer(midiDevice.getMaxReceivers());
                }

                data[4][1] = valueTransmitter;
                data[5][1] = valueReceiver;
            } catch(MidiUnavailableException mue) {
                data[4][1] = "Unknown";
                data[5][1] = "Unknown";
            }
            md = new MediaData(midiDeviceInfo[ii].getName(), columnNames, data);
            soundMIDINode.add( new DefaultMutableTreeNode(md) );
        }

        tree = new JTree(treeModel);
        tree.setRootVisible(false);
        tree.getSelectionModel().setSelectionMode
            (TreeSelectionModel.SINGLE_TREE_SELECTION);
        tree.addTreeSelectionListener( new TreeSelectionListener() {
            public void valueChanged(TreeSelectionEvent tse) {
                if (sortable) {
                    output.setText("Click table column headers to sort.");
                }

                DefaultMutableTreeNode node = (DefaultMutableTreeNode)
                    tree.getLastSelectedPathComponent();

                if (node == null) return;

                Object nodeInfo = node.getUserObject();
                if (nodeInfo instanceof MediaData) {
                    MediaData mediaData = (MediaData)nodeInfo;
                    table.setModel( new DefaultTableModel(
                        mediaData.getData(),
                        mediaData.getColumnNames()) );
                }
            }
        } );

        for (int ii=0; ii<tree.getRowCount(); ii++) {
            tree.expandRow(ii);
        }

        String[] paths = path.split("\\|");
        int row = 0;
        TreePath treePath = null;
        for (String prefix : paths) {
            treePath = tree.getNextMatch( prefix, row, Position.Bias.Forward );
            row = tree.getRowForPath(treePath);
        }

        panel.add(new JScrollPane(tree),BorderLayout.WEST);

        tree.setSelectionPath(treePath);
        tree.scrollRowToVisible(row);
    }
}

class MediaData {

    String name;
    String[] columnNames;
    Object[][] data;

    MediaData(String name, String columnName, Object[] data) {
        this.name = name;

        columnNames = new String[1];
        columnNames[0] = columnName;

        this.data = new Object[data.length][1];
        for (int ii=0; ii<data.length; ii++) {
            this.data[ii][0] = data[ii];
        }
    }

    MediaData(String name, String[] columnNames, Object[][] data) {
        this.name = name;
        this.columnNames = columnNames;
        this.data = data;
    }

    public String toString() {
        return name;
    }

    public String[] getColumnNames() {
        return columnNames;
    }

    public Object[][] getData() {
        return data;
    }
}

屏幕截图