--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/sound/midi/MidiSystem.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,1463 @@
+/*
+ * Copyright 1999-2006 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package javax.sound.midi;
+
+import java.io.FileInputStream;
+import java.io.File;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.IOException;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Set;
+
+import java.net.URL;
+
+import javax.sound.midi.spi.MidiFileWriter;
+import javax.sound.midi.spi.MidiFileReader;
+import javax.sound.midi.spi.SoundbankReader;
+import javax.sound.midi.spi.MidiDeviceProvider;
+
+import com.sun.media.sound.JDK13Services;
+import com.sun.media.sound.ReferenceCountingDevice;
+import com.sun.media.sound.AutoConnectSequencer;
+
+
+/**
+ * The <code>MidiSystem</code> class provides access to the installed MIDI
+ * system resources, including devices such as synthesizers, sequencers, and
+ * MIDI input and output ports. A typical simple MIDI application might
+ * begin by invoking one or more <code>MidiSystem</code> methods to learn
+ * what devices are installed and to obtain the ones needed in that
+ * application.
+ * <p>
+ * The class also has methods for reading files, streams, and URLs that
+ * contain standard MIDI file data or soundbanks. You can query the
+ * <code>MidiSystem</code> for the format of a specified MIDI file.
+ * <p>
+ * You cannot instantiate a <code>MidiSystem</code>; all the methods are
+ * static.
+ *
+ * <p>Properties can be used to specify default MIDI devices.
+ * Both system properties and a properties file are considered.
+ * The properties file is "lib/sound.properties" in the JRE
+ * directory. If a property exists both as a system property and in the
+ * properties file, the system property takes precedence. If none is
+ * specified, a suitable default is chosen among the available devices.
+ * The syntax of the properties file is specified in
+ * {@link java.util.Properties#load(InputStream) Properties.load}. The
+ * following table lists the available property keys and which methods
+ * consider them:
+ *
+ * <table border=0>
+ * <tr>
+ * <th>Property Key</th>
+ * <th>Interface</th>
+ * <th>Affected Method</th>
+ * </tr>
+ * <tr>
+ * <td><code>javax.sound.midi.Receiver</code></td>
+ * <td>{@link Receiver}</td>
+ * <td>{@link #getReceiver}</td>
+ * </tr>
+ * <tr>
+ * <td><code>javax.sound.midi.Sequencer</code></td>
+ * <td>{@link Sequencer}</td>
+ * <td>{@link #getSequencer}</td>
+ * </tr>
+ * <tr>
+ * <td><code>javax.sound.midi.Synthesizer</code></td>
+ * <td>{@link Synthesizer}</td>
+ * <td>{@link #getSynthesizer}</td>
+ * </tr>
+ * <tr>
+ * <td><code>javax.sound.midi.Transmitter</code></td>
+ * <td>{@link Transmitter}</td>
+ * <td>{@link #getTransmitter}</td>
+ * </tr>
+ * </table>
+ *
+ * The property value consists of the provider class name
+ * and the device name, separated by the hash mark ("#").
+ * The provider class name is the fully-qualified
+ * name of a concrete {@link javax.sound.midi.spi.MidiDeviceProvider
+ * MIDI device provider} class. The device name is matched against
+ * the <code>String</code> returned by the <code>getName</code>
+ * method of <code>MidiDevice.Info</code>.
+ * Either the class name, or the device name may be omitted.
+ * If only the class name is specified, the trailing hash mark
+ * is optional.
+ *
+ * <p>If the provider class is specified, and it can be
+ * successully retrieved from the installed providers,
+ * the list of
+ * <code>MidiDevice.Info</code> objects is retrieved
+ * from the provider. Otherwise, or when these devices
+ * do not provide a subsequent match, the list is retrieved
+ * from {@link #getMidiDeviceInfo} to contain
+ * all available <code>MidiDevice.Info</code> objects.
+ *
+ * <p>If a device name is specified, the resulting list of
+ * <code>MidiDevice.Info</code> objects is searched:
+ * the first one with a matching name, and whose
+ * <code>MidiDevice</code> implements the
+ * respective interface, will be returned.
+ * If no matching <code>MidiDevice.Info</code> object
+ * is found, or the device name is not specified,
+ * the first suitable device from the resulting
+ * list will be returned. For Sequencer and Synthesizer,
+ * a device is suitable if it implements the respective
+ * interface; whereas for Receiver and Transmitter, a device is
+ * suitable if it
+ * implements neither Sequencer nor Synthesizer and provides
+ * at least one Receiver or Transmitter, respectively.
+ *
+ * For example, the property <code>javax.sound.midi.Receiver</code>
+ * with a value
+ * <code>"com.sun.media.sound.MidiProvider#SunMIDI1"</code>
+ * will have the following consequences when
+ * <code>getReceiver</code> is called:
+ * if the class <code>com.sun.media.sound.MidiProvider</code> exists
+ * in the list of installed MIDI device providers,
+ * the first <code>Receiver</code> device with name
+ * <code>"SunMIDI1"</code> will be returned. If it cannot
+ * be found, the first <code>Receiver</code> from that provider
+ * will be returned, regardless of name.
+ * If there is none, the first <code>Receiver</code> with name
+ * <code>"SunMIDI1"</code> in the list of all devices
+ * (as returned by <code>getMidiDeviceInfo</code>) will be returned,
+ * or, if not found, the first <code>Receiver</code> that can
+ * be found in the list of all devices is returned.
+ * If that fails, too, a <code>MidiUnavailableException</code>
+ * is thrown.
+ *
+ * @author Kara Kytle
+ * @author Florian Bomers
+ * @author Matthias Pfisterer
+ */
+public class MidiSystem {
+
+ /**
+ * Private no-args constructor for ensuring against instantiation.
+ */
+ private MidiSystem() {
+ }
+
+
+ /**
+ * Obtains an array of information objects representing
+ * the set of all MIDI devices available on the system.
+ * A returned information object can then be used to obtain the
+ * corresponding device object, by invoking
+ * {@link #getMidiDevice(MidiDevice.Info) getMidiDevice}.
+ *
+ * @return an array of <code>MidiDevice.Info</code> objects, one
+ * for each installed MIDI device. If no such devices are installed,
+ * an array of length 0 is returned.
+ */
+ public static MidiDevice.Info[] getMidiDeviceInfo() {
+ List allInfos = new ArrayList();
+ List providers = getMidiDeviceProviders();
+
+ for(int i = 0; i < providers.size(); i++) {
+ MidiDeviceProvider provider = (MidiDeviceProvider) providers.get(i);
+ MidiDevice.Info[] tmpinfo = provider.getDeviceInfo();
+ for (int j = 0; j < tmpinfo.length; j++) {
+ allInfos.add( tmpinfo[j] );
+ }
+ }
+ MidiDevice.Info[] infosArray = (MidiDevice.Info[]) allInfos.toArray(new MidiDevice.Info[0]);
+ return infosArray;
+ }
+
+
+ /**
+ * Obtains the requested MIDI device.
+ *
+ * @param info a device information object representing the desired device.
+ * @return the requested device
+ * @throws MidiUnavailableException if the requested device is not available
+ * due to resource restrictions
+ * @throws IllegalArgumentException if the info object does not represent
+ * a MIDI device installed on the system
+ * @see #getMidiDeviceInfo
+ */
+ public static MidiDevice getMidiDevice(MidiDevice.Info info) throws MidiUnavailableException {
+ List providers = getMidiDeviceProviders();
+
+ for(int i = 0; i < providers.size(); i++) {
+ MidiDeviceProvider provider = (MidiDeviceProvider) providers.get(i);
+ if (provider.isDeviceSupported(info)) {
+ MidiDevice device = provider.getDevice(info);
+ return device;
+ }
+ }
+ throw new IllegalArgumentException("Requested device not installed: " + info);
+ }
+
+
+ /**
+ * Obtains a MIDI receiver from an external MIDI port
+ * or other default device.
+ *
+ * <p>If the system property
+ * <code>javax.sound.midi.Receiver</code>
+ * is defined or it is defined in the file "sound.properties",
+ * it is used to identify the device that provides the default receiver.
+ * For details, refer to the {@link MidiSystem class description}.
+ *
+ * If a suitable MIDI port is not available, the Receiver is
+ * retrieved from an installed synthesizer.
+ *
+ * <p>If this method returns successfully, the {@link
+ * javax.sound.midi.MidiDevice MidiDevice} the
+ * <code>Receiver</code> belongs to is opened implicitly, if it is
+ * not already open. It is possible to close an implicitly opened
+ * device by calling {@link javax.sound.midi.Receiver#close close}
+ * on the returned <code>Receiver</code>. All open <code>Receiver</code>
+ * instances have to be closed in order to release system resources
+ * hold by the <code>MidiDevice</code>. For a
+ * detailed description of open/close behaviour see the class
+ * description of {@link javax.sound.midi.MidiDevice MidiDevice}.
+ *
+ *
+ * @return the default MIDI receiver
+ * @throws MidiUnavailableException if the default receiver is not
+ * available due to resource restrictions,
+ * or no device providing receivers is installed in the system
+ */
+ public static Receiver getReceiver() throws MidiUnavailableException {
+ // may throw MidiUnavailableException
+ MidiDevice device = getDefaultDeviceWrapper(Receiver.class);
+ Receiver receiver;
+ if (device instanceof ReferenceCountingDevice) {
+ receiver = ((ReferenceCountingDevice) device).getReceiverReferenceCounting();
+ } else {
+ receiver = device.getReceiver();
+ }
+ return receiver;
+ }
+
+
+ /**
+ * Obtains a MIDI transmitter from an external MIDI port
+ * or other default source.
+ *
+ * <p>If the system property
+ * <code>javax.sound.midi.Transmitter</code>
+ * is defined or it is defined in the file "sound.properties",
+ * it is used to identify the device that provides the default transmitter.
+ * For details, refer to the {@link MidiSystem class description}.
+ *
+ * If this method returns successfully, the {@link
+ * javax.sound.midi.MidiDevice MidiDevice} the
+ * <code>Transmitter</code> belongs to is opened implicitly, if it
+ * is not already open. It is possible to close an implicitly
+ * opened device by calling {@link
+ * javax.sound.midi.Transmitter#close close} on the returned
+ * <code>Transmitter</code>. All open <code>Transmitter</code>
+ * instances have to be closed in order to release system resources
+ * hold by the <code>MidiDevice</code>. For a detailed description
+ * of open/close behaviour see the class description of {@link
+ * javax.sound.midi.MidiDevice MidiDevice}.
+ *
+ * @return the default MIDI transmitter
+ * @throws MidiUnavailableException if the default transmitter is not
+ * available due to resource restrictions,
+ * or no device providing transmitters is installed in the system
+ */
+ public static Transmitter getTransmitter() throws MidiUnavailableException {
+ // may throw MidiUnavailableException
+ MidiDevice device = getDefaultDeviceWrapper(Transmitter.class);
+ Transmitter transmitter;
+ if (device instanceof ReferenceCountingDevice) {
+ transmitter = ((ReferenceCountingDevice) device).getTransmitterReferenceCounting();
+ } else {
+ transmitter = device.getTransmitter();
+ }
+ return transmitter;
+ }
+
+
+ /**
+ * Obtains the default synthesizer.
+ *
+ * <p>If the system property
+ * <code>javax.sound.midi.Synthesizer</code>
+ * is defined or it is defined in the file "sound.properties",
+ * it is used to identify the default synthesizer.
+ * For details, refer to the {@link MidiSystem class description}.
+ *
+ * @return the default synthesizer
+ * @throws MidiUnavailableException if the synthesizer is not
+ * available due to resource restrictions,
+ * or no synthesizer is installed in the system
+ */
+ public static Synthesizer getSynthesizer() throws MidiUnavailableException {
+ // may throw MidiUnavailableException
+ return (Synthesizer) getDefaultDeviceWrapper(Synthesizer.class);
+ }
+
+
+ /**
+ * Obtains the default <code>Sequencer</code>, connected to
+ * a default device.
+ * The returned <code>Sequencer</code> instance is
+ * connected to the default <code>Synthesizer</code>,
+ * as returned by {@link #getSynthesizer}.
+ * If there is no <code>Synthesizer</code>
+ * available, or the default <code>Synthesizer</code>
+ * cannot be opened, the <code>sequencer</code> is connected
+ * to the default <code>Receiver</code>, as returned
+ * by {@link #getReceiver}.
+ * The connection is made by retrieving a <code>Transmitter</code>
+ * instance from the <code>Sequencer</code> and setting its
+ * <code>Receiver</code>.
+ * Closing and re-opening the sequencer will restore the
+ * connection to the default device.
+ *
+ * <p>This method is equivalent to calling
+ * <code>getSequencer(true)</code>.
+ *
+ * <p>If the system property
+ * <code>javax.sound.midi.Sequencer</code>
+ * is defined or it is defined in the file "sound.properties",
+ * it is used to identify the default sequencer.
+ * For details, refer to the {@link MidiSystem class description}.
+ *
+ * @return the default sequencer, connected to a default Receiver
+ * @throws MidiUnavailableException if the sequencer is not
+ * available due to resource restrictions,
+ * or there is no <code>Receiver</code> available by any
+ * installed <code>MidiDevice</code>,
+ * or no sequencer is installed in the system.
+ * @see #getSequencer(boolean)
+ * @see #getSynthesizer
+ * @see #getReceiver
+ */
+ public static Sequencer getSequencer() throws MidiUnavailableException {
+ return getSequencer(true);
+ }
+
+
+
+ /**
+ * Obtains the default <code>Sequencer</code>, optionally
+ * connected to a default device.
+ *
+ * <p>If <code>connected</code> is true, the returned
+ * <code>Sequencer</code> instance is
+ * connected to the default <code>Synthesizer</code>,
+ * as returned by {@link #getSynthesizer}.
+ * If there is no <code>Synthesizer</code>
+ * available, or the default <code>Synthesizer</code>
+ * cannot be opened, the <code>sequencer</code> is connected
+ * to the default <code>Receiver</code>, as returned
+ * by {@link #getReceiver}.
+ * The connection is made by retrieving a <code>Transmitter</code>
+ * instance from the <code>Sequencer</code> and setting its
+ * <code>Receiver</code>.
+ * Closing and re-opening the sequencer will restore the
+ * connection to the default device.
+ *
+ * <p>If <code>connected</code> is false, the returned
+ * <code>Sequencer</code> instance is not connected, it
+ * has no open <code>Transmitters</code>. In order to
+ * play the sequencer on a MIDI device, or a <code>Synthesizer</code>,
+ * it is necessary to get a <code>Transmitter</code> and set its
+ * <code>Receiver</code>.
+ *
+ * <p>If the system property
+ * <code>javax.sound.midi.Sequencer</code>
+ * is defined or it is defined in the file "sound.properties",
+ * it is used to identify the default sequencer.
+ * For details, refer to the {@link MidiSystem class description}.
+ *
+ * @return the default sequencer
+ * @throws MidiUnavailableException if the sequencer is not
+ * available due to resource restrictions,
+ * or no sequencer is installed in the system,
+ * or if <code>connected</code> is true, and there is
+ * no <code>Receiver</code> available by any installed
+ * <code>MidiDevice</code>
+ * @see #getSynthesizer
+ * @see #getReceiver
+ * @since 1.5
+ */
+ public static Sequencer getSequencer(boolean connected)
+ throws MidiUnavailableException {
+ Sequencer seq = (Sequencer) getDefaultDeviceWrapper(Sequencer.class);
+
+ if (connected) {
+ // IMPORTANT: this code needs to be synch'ed with
+ // all AutoConnectSequencer instances,
+ // (e.g. RealTimeSequencer) because the
+ // same algorithm for synth retrieval
+ // needs to be used!
+
+ Receiver rec = null;
+ MidiUnavailableException mue = null;
+
+ // first try to connect to the default synthesizer
+ try {
+ Synthesizer synth = getSynthesizer();
+ if (synth instanceof ReferenceCountingDevice) {
+ rec = ((ReferenceCountingDevice) synth).getReceiverReferenceCounting();
+ // only use MixerSynth if it could successfully load a soundbank
+ if (synth.getClass().toString().contains("com.sun.media.sound.MixerSynth")
+ && (synth.getDefaultSoundbank() == null)) {
+ // don't use this receiver if no soundbank available
+ rec = null;
+ synth.close();
+ }
+ } else {
+ synth.open();
+ try {
+ rec = synth.getReceiver();
+ } finally {
+ // make sure that the synth is properly closed
+ if (rec == null) {
+ synth.close();
+ }
+ }
+ }
+ } catch (MidiUnavailableException e) {
+ // something went wrong with synth
+ if (e instanceof MidiUnavailableException) {
+ mue = (MidiUnavailableException) e;
+ }
+ }
+ if (rec == null) {
+ // then try to connect to the default Receiver
+ try {
+ rec = MidiSystem.getReceiver();
+ } catch (Exception e) {
+ // something went wrong. Nothing to do then!
+ if (e instanceof MidiUnavailableException) {
+ mue = (MidiUnavailableException) e;
+ }
+ }
+ }
+ if (rec != null) {
+ seq.getTransmitter().setReceiver(rec);
+ if (seq instanceof AutoConnectSequencer) {
+ ((AutoConnectSequencer) seq).setAutoConnect(rec);
+ }
+ } else {
+ if (mue != null) {
+ throw mue;
+ }
+ throw new MidiUnavailableException("no receiver available");
+ }
+ }
+ return seq;
+ }
+
+
+
+
+ /**
+ * Constructs a MIDI sound bank by reading it from the specified stream.
+ * The stream must point to
+ * a valid MIDI soundbank file. In general, MIDI soundbank providers may
+ * need to read some data from the stream before determining whether they
+ * support it. These parsers must
+ * be able to mark the stream, read enough data to determine whether they
+ * support the stream, and, if not, reset the stream's read pointer to
+ * its original position. If the input stream does not support this,
+ * this method may fail with an IOException.
+ * @param stream the source of the sound bank data.
+ * @return the sound bank
+ * @throws InvalidMidiDataException if the stream does not point to
+ * valid MIDI soundbank data recognized by the system
+ * @throws IOException if an I/O error occurred when loading the soundbank
+ * @see InputStream#markSupported
+ * @see InputStream#mark
+ */
+ public static Soundbank getSoundbank(InputStream stream)
+ throws InvalidMidiDataException, IOException {
+
+ SoundbankReader sp = null;
+ Soundbank s = null;
+
+ List providers = getSoundbankReaders();
+
+ for(int i = 0; i < providers.size(); i++) {
+ sp = (SoundbankReader)providers.get(i);
+ s = sp.getSoundbank(stream);
+
+ if( s!= null) {
+ return s;
+ }
+ }
+ throw new InvalidMidiDataException("cannot get soundbank from stream");
+
+ }
+
+
+ /**
+ * Constructs a <code>Soundbank</code> by reading it from the specified URL.
+ * The URL must point to a valid MIDI soundbank file.
+ *
+ * @param url the source of the sound bank data
+ * @return the sound bank
+ * @throws InvalidMidiDataException if the URL does not point to valid MIDI
+ * soundbank data recognized by the system
+ * @throws IOException if an I/O error occurred when loading the soundbank
+ */
+ public static Soundbank getSoundbank(URL url)
+ throws InvalidMidiDataException, IOException {
+
+ SoundbankReader sp = null;
+ Soundbank s = null;
+
+ List providers = getSoundbankReaders();
+
+ for(int i = 0; i < providers.size(); i++) {
+ sp = (SoundbankReader)providers.get(i);
+ s = sp.getSoundbank(url);
+
+ if( s!= null) {
+ return s;
+ }
+ }
+ throw new InvalidMidiDataException("cannot get soundbank from stream");
+
+ }
+
+
+ /**
+ * Constructs a <code>Soundbank</code> by reading it from the specified
+ * <code>File</code>.
+ * The <code>File</code> must point to a valid MIDI soundbank file.
+ *
+ * @param file the source of the sound bank data
+ * @return the sound bank
+ * @throws InvalidMidiDataException if the <code>File</code> does not
+ * point to valid MIDI soundbank data recognized by the system
+ * @throws IOException if an I/O error occurred when loading the soundbank
+ */
+ public static Soundbank getSoundbank(File file)
+ throws InvalidMidiDataException, IOException {
+
+ SoundbankReader sp = null;
+ Soundbank s = null;
+
+ List providers = getSoundbankReaders();
+
+ for(int i = 0; i < providers.size(); i++) {
+ sp = (SoundbankReader)providers.get(i);
+ s = sp.getSoundbank(file);
+
+ if( s!= null) {
+ return s;
+ }
+ }
+ throw new InvalidMidiDataException("cannot get soundbank from stream");
+ }
+
+
+
+ /**
+ * Obtains the MIDI file format of the data in the specified input stream.
+ * The stream must point to valid MIDI file data for a file type recognized
+ * by the system.
+ * <p>
+ * This method and/or the code it invokes may need to read some data from
+ * the stream to determine whether its data format is supported. The
+ * implementation may therefore
+ * need to mark the stream, read enough data to determine whether it is in
+ * a supported format, and reset the stream's read pointer to its original
+ * position. If the input stream does not permit this set of operations,
+ * this method may fail with an <code>IOException</code>.
+ * <p>
+ * This operation can only succeed for files of a type which can be parsed
+ * by an installed file reader. It may fail with an InvalidMidiDataException
+ * even for valid files if no compatible file reader is installed. It
+ * will also fail with an InvalidMidiDataException if a compatible file reader
+ * is installed, but encounters errors while determining the file format.
+ *
+ * @param stream the input stream from which file format information
+ * should be extracted
+ * @return an <code>MidiFileFormat</code> object describing the MIDI file
+ * format
+ * @throws InvalidMidiDataException if the stream does not point to valid
+ * MIDI file data recognized by the system
+ * @throws IOException if an I/O exception occurs while accessing the
+ * stream
+ * @see #getMidiFileFormat(URL)
+ * @see #getMidiFileFormat(File)
+ * @see InputStream#markSupported
+ * @see InputStream#mark
+ */
+ public static MidiFileFormat getMidiFileFormat(InputStream stream)
+ throws InvalidMidiDataException, IOException {
+
+ List providers = getMidiFileReaders();
+ MidiFileFormat format = null;
+
+ for(int i = 0; i < providers.size(); i++) {
+ MidiFileReader reader = (MidiFileReader) providers.get(i);
+ try {
+ format = reader.getMidiFileFormat( stream ); // throws IOException
+ break;
+ } catch (InvalidMidiDataException e) {
+ continue;
+ }
+ }
+
+ if( format==null ) {
+ throw new InvalidMidiDataException("input stream is not a supported file type");
+ } else {
+ return format;
+ }
+ }
+
+
+ /**
+ * Obtains the MIDI file format of the data in the specified URL. The URL
+ * must point to valid MIDI file data for a file type recognized
+ * by the system.
+ * <p>
+ * This operation can only succeed for files of a type which can be parsed
+ * by an installed file reader. It may fail with an InvalidMidiDataException
+ * even for valid files if no compatible file reader is installed. It
+ * will also fail with an InvalidMidiDataException if a compatible file reader
+ * is installed, but encounters errors while determining the file format.
+ *
+ * @param url the URL from which file format information should be
+ * extracted
+ * @return a <code>MidiFileFormat</code> object describing the MIDI file
+ * format
+ * @throws InvalidMidiDataException if the URL does not point to valid MIDI
+ * file data recognized by the system
+ * @throws IOException if an I/O exception occurs while accessing the URL
+ *
+ * @see #getMidiFileFormat(InputStream)
+ * @see #getMidiFileFormat(File)
+ */
+ public static MidiFileFormat getMidiFileFormat(URL url)
+ throws InvalidMidiDataException, IOException {
+
+ List providers = getMidiFileReaders();
+ MidiFileFormat format = null;
+
+ for(int i = 0; i < providers.size(); i++) {
+ MidiFileReader reader = (MidiFileReader) providers.get(i);
+ try {
+ format = reader.getMidiFileFormat( url ); // throws IOException
+ break;
+ } catch (InvalidMidiDataException e) {
+ continue;
+ }
+ }
+
+ if( format==null ) {
+ throw new InvalidMidiDataException("url is not a supported file type");
+ } else {
+ return format;
+ }
+ }
+
+
+ /**
+ * Obtains the MIDI file format of the specified <code>File</code>. The
+ * <code>File</code> must point to valid MIDI file data for a file type
+ * recognized by the system.
+ * <p>
+ * This operation can only succeed for files of a type which can be parsed
+ * by an installed file reader. It may fail with an InvalidMidiDataException
+ * even for valid files if no compatible file reader is installed. It
+ * will also fail with an InvalidMidiDataException if a compatible file reader
+ * is installed, but encounters errors while determining the file format.
+ *
+ * @param file the <code>File</code> from which file format information
+ * should be extracted
+ * @return a <code>MidiFileFormat</code> object describing the MIDI file
+ * format
+ * @throws InvalidMidiDataException if the <code>File</code> does not point
+ * to valid MIDI file data recognized by the system
+ * @throws IOException if an I/O exception occurs while accessing the file
+ *
+ * @see #getMidiFileFormat(InputStream)
+ * @see #getMidiFileFormat(URL)
+ */
+ public static MidiFileFormat getMidiFileFormat(File file)
+ throws InvalidMidiDataException, IOException {
+
+ List providers = getMidiFileReaders();
+ MidiFileFormat format = null;
+
+ for(int i = 0; i < providers.size(); i++) {
+ MidiFileReader reader = (MidiFileReader) providers.get(i);
+ try {
+ format = reader.getMidiFileFormat( file ); // throws IOException
+ break;
+ } catch (InvalidMidiDataException e) {
+ continue;
+ }
+ }
+
+ if( format==null ) {
+ throw new InvalidMidiDataException("file is not a supported file type");
+ } else {
+ return format;
+ }
+ }
+
+
+ /**
+ * Obtains a MIDI sequence from the specified input stream. The stream must
+ * point to valid MIDI file data for a file type recognized
+ * by the system.
+ * <p>
+ * This method and/or the code it invokes may need to read some data
+ * from the stream to determine whether
+ * its data format is supported. The implementation may therefore
+ * need to mark the stream, read enough data to determine whether it is in
+ * a supported format, and reset the stream's read pointer to its original
+ * position. If the input stream does not permit this set of operations,
+ * this method may fail with an <code>IOException</code>.
+ * <p>
+ * This operation can only succeed for files of a type which can be parsed
+ * by an installed file reader. It may fail with an InvalidMidiDataException
+ * even for valid files if no compatible file reader is installed. It
+ * will also fail with an InvalidMidiDataException if a compatible file reader
+ * is installed, but encounters errors while constructing the <code>Sequence</code>
+ * object from the file data.
+ *
+ * @param stream the input stream from which the <code>Sequence</code>
+ * should be constructed
+ * @return a <code>Sequence</code> object based on the MIDI file data
+ * contained in the input stream
+ * @throws InvalidMidiDataException if the stream does not point to
+ * valid MIDI file data recognized by the system
+ * @throws IOException if an I/O exception occurs while accessing the
+ * stream
+ * @see InputStream#markSupported
+ * @see InputStream#mark
+ */
+ public static Sequence getSequence(InputStream stream)
+ throws InvalidMidiDataException, IOException {
+
+ List providers = getMidiFileReaders();
+ Sequence sequence = null;
+
+ for(int i = 0; i < providers.size(); i++) {
+ MidiFileReader reader = (MidiFileReader) providers.get(i);
+ try {
+ sequence = reader.getSequence( stream ); // throws IOException
+ break;
+ } catch (InvalidMidiDataException e) {
+ continue;
+ }
+ }
+
+ if( sequence==null ) {
+ throw new InvalidMidiDataException("could not get sequence from input stream");
+ } else {
+ return sequence;
+ }
+ }
+
+
+ /**
+ * Obtains a MIDI sequence from the specified URL. The URL must
+ * point to valid MIDI file data for a file type recognized
+ * by the system.
+ * <p>
+ * This operation can only succeed for files of a type which can be parsed
+ * by an installed file reader. It may fail with an InvalidMidiDataException
+ * even for valid files if no compatible file reader is installed. It
+ * will also fail with an InvalidMidiDataException if a compatible file reader
+ * is installed, but encounters errors while constructing the <code>Sequence</code>
+ * object from the file data.
+ *
+ * @param url the URL from which the <code>Sequence</code> should be
+ * constructed
+ * @return a <code>Sequence</code> object based on the MIDI file data
+ * pointed to by the URL
+ * @throws InvalidMidiDataException if the URL does not point to valid MIDI
+ * file data recognized by the system
+ * @throws IOException if an I/O exception occurs while accessing the URL
+ */
+ public static Sequence getSequence(URL url)
+ throws InvalidMidiDataException, IOException {
+
+ List providers = getMidiFileReaders();
+ Sequence sequence = null;
+
+ for(int i = 0; i < providers.size(); i++) {
+ MidiFileReader reader = (MidiFileReader) providers.get(i);
+ try {
+ sequence = reader.getSequence( url ); // throws IOException
+ break;
+ } catch (InvalidMidiDataException e) {
+ continue;
+ }
+ }
+
+ if( sequence==null ) {
+ throw new InvalidMidiDataException("could not get sequence from URL");
+ } else {
+ return sequence;
+ }
+ }
+
+
+ /**
+ * Obtains a MIDI sequence from the specified <code>File</code>.
+ * The <code>File</code> must point to valid MIDI file data
+ * for a file type recognized by the system.
+ * <p>
+ * This operation can only succeed for files of a type which can be parsed
+ * by an installed file reader. It may fail with an InvalidMidiDataException
+ * even for valid files if no compatible file reader is installed. It
+ * will also fail with an InvalidMidiDataException if a compatible file reader
+ * is installed, but encounters errors while constructing the <code>Sequence</code>
+ * object from the file data.
+ *
+ * @param file the <code>File</code> from which the <code>Sequence</code>
+ * should be constructed
+ * @return a <code>Sequence</code> object based on the MIDI file data
+ * pointed to by the File
+ * @throws InvalidMidiDataException if the File does not point to valid MIDI
+ * file data recognized by the system
+ * @throws IOException if an I/O exception occurs
+ */
+ public static Sequence getSequence(File file)
+ throws InvalidMidiDataException, IOException {
+
+ List providers = getMidiFileReaders();
+ Sequence sequence = null;
+
+ for(int i = 0; i < providers.size(); i++) {
+ MidiFileReader reader = (MidiFileReader) providers.get(i);
+ try {
+ sequence = reader.getSequence( file ); // throws IOException
+ break;
+ } catch (InvalidMidiDataException e) {
+ continue;
+ }
+ }
+
+ if( sequence==null ) {
+ throw new InvalidMidiDataException("could not get sequence from file");
+ } else {
+ return sequence;
+ }
+ }
+
+
+ /**
+ * Obtains the set of MIDI file types for which file writing support is
+ * provided by the system.
+ * @return array of unique file types. If no file types are supported,
+ * an array of length 0 is returned.
+ */
+ public static int[] getMidiFileTypes() {
+
+ List providers = getMidiFileWriters();
+ Set allTypes = new HashSet();
+
+ // gather from all the providers
+
+ for (int i = 0; i < providers.size(); i++ ) {
+ MidiFileWriter writer = (MidiFileWriter) providers.get(i);
+ int[] types = writer.getMidiFileTypes();
+ for (int j = 0; j < types.length; j++ ) {
+ allTypes.add(new Integer(types[j]));
+ }
+ }
+ int resultTypes[] = new int[allTypes.size()];
+ int index = 0;
+ Iterator iterator = allTypes.iterator();
+ while (iterator.hasNext()) {
+ Integer integer = (Integer) iterator.next();
+ resultTypes[index++] = integer.intValue();
+ }
+ return resultTypes;
+ }
+
+
+ /**
+ * Indicates whether file writing support for the specified MIDI file type
+ * is provided by the system.
+ * @param fileType the file type for which write capabilities are queried
+ * @return <code>true</code> if the file type is supported,
+ * otherwise <code>false</code>
+ */
+ public static boolean isFileTypeSupported(int fileType) {
+
+ List providers = getMidiFileWriters();
+
+ for (int i = 0; i < providers.size(); i++ ) {
+ MidiFileWriter writer = (MidiFileWriter) providers.get(i);
+ if( writer.isFileTypeSupported(fileType)) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+
+ /**
+ * Obtains the set of MIDI file types that the system can write from the
+ * sequence specified.
+ * @param sequence the sequence for which MIDI file type support
+ * is queried
+ * @return the set of unique supported file types. If no file types are supported,
+ * returns an array of length 0.
+ */
+ public static int[] getMidiFileTypes(Sequence sequence) {
+
+ List providers = getMidiFileWriters();
+ Set allTypes = new HashSet();
+
+ // gather from all the providers
+
+ for (int i = 0; i < providers.size(); i++ ) {
+ MidiFileWriter writer = (MidiFileWriter) providers.get(i);
+ int[] types = writer.getMidiFileTypes(sequence);
+ for (int j = 0; j < types.length; j++ ) {
+ allTypes.add(new Integer(types[j]));
+ }
+ }
+ int resultTypes[] = new int[allTypes.size()];
+ int index = 0;
+ Iterator iterator = allTypes.iterator();
+ while (iterator.hasNext()) {
+ Integer integer = (Integer) iterator.next();
+ resultTypes[index++] = integer.intValue();
+ }
+ return resultTypes;
+ }
+
+
+ /**
+ * Indicates whether a MIDI file of the file type specified can be written
+ * from the sequence indicated.
+ * @param fileType the file type for which write capabilities
+ * are queried
+ * @param sequence the sequence for which file writing support is queried
+ * @return <code>true</code> if the file type is supported for this
+ * sequence, otherwise <code>false</code>
+ */
+ public static boolean isFileTypeSupported(int fileType, Sequence sequence) {
+
+ List providers = getMidiFileWriters();
+
+ for (int i = 0; i < providers.size(); i++ ) {
+ MidiFileWriter writer = (MidiFileWriter) providers.get(i);
+ if( writer.isFileTypeSupported(fileType,sequence)) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+
+ /**
+ * Writes a stream of bytes representing a file of the MIDI file type
+ * indicated to the output stream provided.
+ * @param in sequence containing MIDI data to be written to the file
+ * @param fileType the file type of the file to be written to the output stream
+ * @param out stream to which the file data should be written
+ * @return the number of bytes written to the output stream
+ * @throws IOException if an I/O exception occurs
+ * @throws IllegalArgumentException if the file format is not supported by
+ * the system
+ * @see #isFileTypeSupported(int, Sequence)
+ * @see #getMidiFileTypes(Sequence)
+ */
+ public static int write(Sequence in, int fileType, OutputStream out) throws IOException {
+
+ List providers = getMidiFileWriters();
+ //$$fb 2002-04-17: Fix for 4635287: Standard MidiFileWriter cannot write empty Sequences
+ int bytesWritten = -2;
+
+ for (int i = 0; i < providers.size(); i++ ) {
+ MidiFileWriter writer = (MidiFileWriter) providers.get(i);
+ if( writer.isFileTypeSupported( fileType, in ) ) {
+
+ bytesWritten = writer.write(in, fileType, out);
+ break;
+ }
+ }
+ if (bytesWritten == -2) {
+ throw new IllegalArgumentException("MIDI file type is not supported");
+ }
+ return bytesWritten;
+ }
+
+
+ /**
+ * Writes a stream of bytes representing a file of the MIDI file type
+ * indicated to the external file provided.
+ * @param in sequence containing MIDI data to be written to the file
+ * @param type the file type of the file to be written to the output stream
+ * @param out external file to which the file data should be written
+ * @return the number of bytes written to the file
+ * @throws IOException if an I/O exception occurs
+ * @throws IllegalArgumentException if the file type is not supported by
+ * the system
+ * @see #isFileTypeSupported(int, Sequence)
+ * @see #getMidiFileTypes(Sequence)
+ */
+ public static int write(Sequence in, int type, File out) throws IOException {
+
+ List providers = getMidiFileWriters();
+ //$$fb 2002-04-17: Fix for 4635287: Standard MidiFileWriter cannot write empty Sequences
+ int bytesWritten = -2;
+
+ for (int i = 0; i < providers.size(); i++ ) {
+ MidiFileWriter writer = (MidiFileWriter) providers.get(i);
+ if( writer.isFileTypeSupported( type, in ) ) {
+
+ bytesWritten = writer.write(in, type, out);
+ break;
+ }
+ }
+ if (bytesWritten == -2) {
+ throw new IllegalArgumentException("MIDI file type is not supported");
+ }
+ return bytesWritten;
+ }
+
+
+
+ // HELPER METHODS
+
+ private static List getMidiDeviceProviders() {
+ return getProviders(MidiDeviceProvider.class);
+ }
+
+
+ private static List getSoundbankReaders() {
+ return getProviders(SoundbankReader.class);
+ }
+
+
+ private static List getMidiFileWriters() {
+ return getProviders(MidiFileWriter.class);
+ }
+
+
+ private static List getMidiFileReaders() {
+ return getProviders(MidiFileReader.class);
+ }
+
+
+ /** Attempts to locate and return a default MidiDevice of the specified
+ * type.
+ *
+ * This method wraps {@link #getDefaultDevice}. It catches the
+ * <code>IllegalArgumentException</code> thrown by
+ * <code>getDefaultDevice</code> and instead throws a
+ * <code>MidiUnavailableException</code>, with the catched
+ * exception chained.
+ *
+ * @param deviceClass The requested device type, one of Synthesizer.class,
+ * Sequencer.class, Receiver.class or Transmitter.class.
+ * @throws MidiUnavalableException on failure.
+ */
+ private static MidiDevice getDefaultDeviceWrapper(Class deviceClass)
+ throws MidiUnavailableException{
+ try {
+ return getDefaultDevice(deviceClass);
+ } catch (IllegalArgumentException iae) {
+ MidiUnavailableException mae = new MidiUnavailableException();
+ mae.initCause(iae);
+ throw mae;
+ }
+ }
+
+
+ /** Attempts to locate and return a default MidiDevice of the specified
+ * type.
+ *
+ * @param deviceClass The requested device type, one of Synthesizer.class,
+ * Sequencer.class, Receiver.class or Transmitter.class.
+ * @throws IllegalArgumentException on failure.
+ */
+ private static MidiDevice getDefaultDevice(Class deviceClass) {
+ List providers = getMidiDeviceProviders();
+ String providerClassName = JDK13Services.getDefaultProviderClassName(deviceClass);
+ String instanceName = JDK13Services.getDefaultInstanceName(deviceClass);
+ MidiDevice device;
+
+ if (providerClassName != null) {
+ MidiDeviceProvider defaultProvider = getNamedProvider(providerClassName, providers);
+ if (defaultProvider != null) {
+ if (instanceName != null) {
+ device = getNamedDevice(instanceName, defaultProvider, deviceClass);
+ if (device != null) {
+ return device;
+ }
+ }
+ device = getFirstDevice(defaultProvider, deviceClass);
+ if (device != null) {
+ return device;
+ }
+ }
+ }
+
+ /* Provider class not specified or cannot be found, or
+ provider class specified, and no appropriate device available or
+ provider class and instance specified and instance cannot be found or is not appropriate */
+ if (instanceName != null) {
+ device = getNamedDevice(instanceName, providers, deviceClass);
+ if (device != null) {
+ return device;
+ }
+ }
+
+ /* No default are specified, or if something is specified, everything
+ failed. */
+ device = getFirstDevice(providers, deviceClass);
+ if (device != null) {
+ return device;
+ }
+ throw new IllegalArgumentException("Requested device not installed");
+ }
+
+
+
+ /** Return a MidiDeviceProcider of a given class from the list of
+ MidiDeviceProviders.
+
+ @param providerClassName The class name of the provider to be returned.
+ @param provider The list of MidiDeviceProviders that is searched.
+ @return A MidiDeviceProvider of the requested class, or null if none
+ is found.
+ */
+ private static MidiDeviceProvider getNamedProvider(String providerClassName, List providers) {
+ for(int i = 0; i < providers.size(); i++) {
+ MidiDeviceProvider provider = (MidiDeviceProvider) providers.get(i);
+ if (provider.getClass().getName().equals(providerClassName)) {
+ return provider;
+ }
+ }
+ return null;
+ }
+
+
+ /** Return a MidiDevice with a given name from a given MidiDeviceProvider.
+ @param deviceName The name of the MidiDevice to be returned.
+ @param provider The MidiDeviceProvider to check for MidiDevices.
+ @param deviceClass The requested device type, one of Synthesizer.class,
+ Sequencer.class, Receiver.class or Transmitter.class.
+
+ @return A MidiDevice matching the requirements, or null if none is found.
+ */
+ private static MidiDevice getNamedDevice(String deviceName,
+ MidiDeviceProvider provider,
+ Class deviceClass) {
+ MidiDevice device;
+ // try to get MIDI port
+ device = getNamedDevice(deviceName, provider, deviceClass,
+ false, false);
+ if (device != null) {
+ return device;
+ }
+
+ if (deviceClass == Receiver.class) {
+ // try to get Synthesizer
+ device = getNamedDevice(deviceName, provider, deviceClass,
+ true, false);
+ if (device != null) {
+ return device;
+ }
+ }
+
+ return null;
+ }
+
+
+ /** Return a MidiDevice with a given name from a given MidiDeviceProvider.
+ @param deviceName The name of the MidiDevice to be returned.
+ @param provider The MidiDeviceProvider to check for MidiDevices.
+ @param deviceClass The requested device type, one of Synthesizer.class,
+ Sequencer.class, Receiver.class or Transmitter.class.
+
+ @return A MidiDevice matching the requirements, or null if none is found.
+ */
+ private static MidiDevice getNamedDevice(String deviceName,
+ MidiDeviceProvider provider,
+ Class deviceClass,
+ boolean allowSynthesizer,
+ boolean allowSequencer) {
+ MidiDevice.Info[] infos = provider.getDeviceInfo();
+ for (int i = 0; i < infos.length; i++) {
+ if (infos[i].getName().equals(deviceName)) {
+ MidiDevice device = provider.getDevice(infos[i]);
+ if (isAppropriateDevice(device, deviceClass,
+ allowSynthesizer, allowSequencer)) {
+ return device;
+ }
+ }
+ }
+ return null;
+ }
+
+
+ /** Return a MidiDevice with a given name from a list of
+ MidiDeviceProviders.
+ @param deviceName The name of the MidiDevice to be returned.
+ @param providers The List of MidiDeviceProviders to check for
+ MidiDevices.
+ @param deviceClass The requested device type, one of Synthesizer.class,
+ Sequencer.class, Receiver.class or Transmitter.class.
+ @return A Mixer matching the requirements, or null if none is found.
+ */
+ private static MidiDevice getNamedDevice(String deviceName,
+ List providers,
+ Class deviceClass) {
+ MidiDevice device;
+ // try to get MIDI port
+ device = getNamedDevice(deviceName, providers, deviceClass,
+ false, false);
+ if (device != null) {
+ return device;
+ }
+
+ if (deviceClass == Receiver.class) {
+ // try to get Synthesizer
+ device = getNamedDevice(deviceName, providers, deviceClass,
+ true, false);
+ if (device != null) {
+ return device;
+ }
+ }
+
+ return null;
+ }
+
+
+ /** Return a MidiDevice with a given name from a list of
+ MidiDeviceProviders.
+ @param deviceName The name of the MidiDevice to be returned.
+ @param providers The List of MidiDeviceProviders to check for
+ MidiDevices.
+ @param deviceClass The requested device type, one of Synthesizer.class,
+ Sequencer.class, Receiver.class or Transmitter.class.
+ @return A Mixer matching the requirements, or null if none is found.
+ */
+ private static MidiDevice getNamedDevice(String deviceName,
+ List providers,
+ Class deviceClass,
+ boolean allowSynthesizer,
+ boolean allowSequencer) {
+ for(int i = 0; i < providers.size(); i++) {
+ MidiDeviceProvider provider = (MidiDeviceProvider) providers.get(i);
+ MidiDevice device = getNamedDevice(deviceName, provider,
+ deviceClass,
+ allowSynthesizer,
+ allowSequencer);
+ if (device != null) {
+ return device;
+ }
+ }
+ return null;
+ }
+
+
+ /** From a given MidiDeviceProvider, return the first appropriate device.
+ @param provider The MidiDeviceProvider to check for MidiDevices.
+ @param deviceClass The requested device type, one of Synthesizer.class,
+ Sequencer.class, Receiver.class or Transmitter.class.
+ @return A MidiDevice is considered appropriate, or null if no
+ appropriate device is found.
+ */
+ private static MidiDevice getFirstDevice(MidiDeviceProvider provider,
+ Class deviceClass) {
+ MidiDevice device;
+ // try to get MIDI port
+ device = getFirstDevice(provider, deviceClass,
+ false, false);
+ if (device != null) {
+ return device;
+ }
+
+ if (deviceClass == Receiver.class) {
+ // try to get Synthesizer
+ device = getFirstDevice(provider, deviceClass,
+ true, false);
+ if (device != null) {
+ return device;
+ }
+ }
+
+ return null;
+ }
+
+
+ /** From a given MidiDeviceProvider, return the first appropriate device.
+ @param provider The MidiDeviceProvider to check for MidiDevices.
+ @param deviceClass The requested device type, one of Synthesizer.class,
+ Sequencer.class, Receiver.class or Transmitter.class.
+ @return A MidiDevice is considered appropriate, or null if no
+ appropriate device is found.
+ */
+ private static MidiDevice getFirstDevice(MidiDeviceProvider provider,
+ Class deviceClass,
+ boolean allowSynthesizer,
+ boolean allowSequencer) {
+ MidiDevice.Info[] infos = provider.getDeviceInfo();
+ for (int j = 0; j < infos.length; j++) {
+ MidiDevice device = provider.getDevice(infos[j]);
+ if (isAppropriateDevice(device, deviceClass,
+ allowSynthesizer, allowSequencer)) {
+ return device;
+ }
+ }
+ return null;
+ }
+
+
+ /** From a List of MidiDeviceProviders, return the first appropriate
+ MidiDevice.
+ @param providers The List of MidiDeviceProviders to search.
+ @param deviceClass The requested device type, one of Synthesizer.class,
+ Sequencer.class, Receiver.class or Transmitter.class.
+ @return A MidiDevice that is considered appropriate, or null
+ if none is found.
+ */
+ private static MidiDevice getFirstDevice(List providers,
+ Class deviceClass) {
+ MidiDevice device;
+ // try to get MIDI port
+ device = getFirstDevice(providers, deviceClass,
+ false, false);
+ if (device != null) {
+ return device;
+ }
+
+ if (deviceClass == Receiver.class) {
+ // try to get Synthesizer
+ device = getFirstDevice(providers, deviceClass,
+ true, false);
+ if (device != null) {
+ return device;
+ }
+ }
+
+ return null;
+ }
+
+
+ /** From a List of MidiDeviceProviders, return the first appropriate
+ MidiDevice.
+ @param providers The List of MidiDeviceProviders to search.
+ @param deviceClass The requested device type, one of Synthesizer.class,
+ Sequencer.class, Receiver.class or Transmitter.class.
+ @return A MidiDevice that is considered appropriate, or null
+ if none is found.
+ */
+ private static MidiDevice getFirstDevice(List providers,
+ Class deviceClass,
+ boolean allowSynthesizer,
+ boolean allowSequencer) {
+ for(int i = 0; i < providers.size(); i++) {
+ MidiDeviceProvider provider = (MidiDeviceProvider) providers.get(i);
+ MidiDevice device = getFirstDevice(provider, deviceClass,
+ allowSynthesizer,
+ allowSequencer);
+ if (device != null) {
+ return device;
+ }
+ }
+ return null;
+ }
+
+
+ /** Checks if a MidiDevice is appropriate.
+ If deviceClass is Synthesizer or Sequencer, a device implementing
+ the respective interface is considered appropriate. If deviceClass
+ is Receiver or Transmitter, a device is considered appropriate if
+ it implements neither Synthesizer nor Transmitter, and if it can
+ provide at least one Receiver or Transmitter, respectively.
+
+ @param device the MidiDevice to test
+ @param allowSynthesizer if true, Synthesizers are considered
+ appropriate. Otherwise only pure MidiDevices are considered
+ appropriate (unless allowSequencer is true). This flag only has an
+ effect for deviceClass Receiver and Transmitter. For other device
+ classes (Sequencer and Synthesizer), this flag has no effect.
+ @param allowSequencer if true, Sequencers are considered
+ appropriate. Otherwise only pure MidiDevices are considered
+ appropriate (unless allowSynthesizer is true). This flag only has an
+ effect for deviceClass Receiver and Transmitter. For other device
+ classes (Sequencer and Synthesizer), this flag has no effect.
+ @return true if the device is considered appropriate according to the
+ rules given above, false otherwise.
+ */
+ private static boolean isAppropriateDevice(MidiDevice device,
+ Class deviceClass,
+ boolean allowSynthesizer,
+ boolean allowSequencer) {
+ if (deviceClass.isInstance(device)) {
+ // This clause is for deviceClass being either Synthesizer
+ // or Sequencer.
+ return true;
+ } else {
+ // Now the case that deviceClass is Transmitter or
+ // Receiver. If neither allowSynthesizer nor allowSequencer is
+ // true, we require device instances to be
+ // neither Synthesizer nor Sequencer, since we only want
+ // devices representing MIDI ports.
+ // Otherwise, the respective type is accepted, too
+ if ( (! (device instanceof Sequencer) &&
+ ! (device instanceof Synthesizer) ) ||
+ ((device instanceof Sequencer) && allowSequencer) ||
+ ((device instanceof Synthesizer) && allowSynthesizer)) {
+ // And of cource, the device has to be able to provide
+ // Receivers or Transmitters.
+ if ((deviceClass == Receiver.class &&
+ device.getMaxReceivers() != 0) ||
+ (deviceClass == Transmitter.class &&
+ device.getMaxTransmitters() != 0)) {
+ return true;
+ }
+ }
+ }
+ return false;
+ }
+
+
+ /**
+ * Obtains the set of services currently installed on the system
+ * using sun.misc.Service, the SPI mechanism in 1.3.
+ * @return a List of instances of providers for the requested service.
+ * If no providers are available, a List of length 0 will be returned.
+ */
+ private static List getProviders(Class providerClass) {
+ return JDK13Services.getProviders(providerClass);
+ }
+}