* Note that the naming convention for this interface reflects the relationship * between the line and its mixer. From the perspective of an application, a * target data line may act as a source for audio data. *
* The target data line can be obtained from a mixer by invoking the * {@link Mixer#getLine getLine} method of {@code Mixer} with an appropriate * {@link DataLine.Info} object. *
* The {@code TargetDataLine} interface provides a method for reading the * captured data from the target data line's buffer. Applications that record * audio should read data from the target data line quickly enough to keep the * buffer from overflowing, which could cause discontinuities in the captured * data that are perceived as clicks. Applications can use the * {@link DataLine#available available} method defined in the {@code DataLine} * interface to determine the amount of data currently queued in the data line's * buffer. If the buffer does overflow, the oldest queued data is discarded and * replaced by new data. * * @author Kara Kytle * @see Mixer * @see DataLine * @see SourceDataLine * @since 1.3 */ public interface TargetDataLine extends DataLine { /** * Opens the line with the specified format and requested buffer size, * causing the line to acquire any required system resources and become * operational. *
* The buffer size is specified in bytes, but must represent an integral * number of sample frames. Invoking this method with a requested buffer * size that does not meet this requirement may result in an * {@code IllegalArgumentException}. The actual buffer size for the open * line may differ from the requested buffer size. The value actually set * may be queried by subsequently calling {@link DataLine#getBufferSize} *
* If this operation succeeds, the line is marked as open, and an * {@link LineEvent.Type#OPEN OPEN} event is dispatched to the line's * listeners. *
* Invoking this method on a line that is already open is illegal and may * result in an {@code IllegalStateException}. *
* Some lines, once closed, cannot be reopened. Attempts to reopen such a * line will always result in a {@code LineUnavailableException}. * * @param format the desired audio format * @param bufferSize the desired buffer size, in bytes * @throws LineUnavailableException if the line cannot be opened due to * resource restrictions * @throws IllegalArgumentException if the buffer size does not represent an * integral number of sample frames, or if {@code format} is not * fully specified or invalid * @throws IllegalStateException if the line is already open * @throws SecurityException if the line cannot be opened due to security * restrictions * @see #open(AudioFormat) * @see Line#open * @see Line#close * @see Line#isOpen * @see LineEvent */ void open(AudioFormat format, int bufferSize) throws LineUnavailableException; /** * Opens the line with the specified format, causing the line to acquire any * required system resources and become operational. *
* The implementation chooses a buffer size, which is measured in bytes but * which encompasses an integral number of sample frames. The buffer size * that the system has chosen may be queried by subsequently calling * {@link DataLine#getBufferSize} *
* If this operation succeeds, the line is marked as open, and an * {@link LineEvent.Type#OPEN OPEN} event is dispatched to the line's * listeners. *
* Invoking this method on a line that is already open is illegal and may * result in an {@code IllegalStateException}. *
* Some lines, once closed, cannot be reopened. Attempts to reopen such a * line will always result in a {@code LineUnavailableException}. * * @param format the desired audio format * @throws LineUnavailableException if the line cannot be opened due to * resource restrictions * @throws IllegalArgumentException if {@code format} is not fully specified * or invalid * @throws IllegalStateException if the line is already open * @throws SecurityException if the line cannot be opened due to security * restrictions * @see #open(AudioFormat, int) * @see Line#open * @see Line#close * @see Line#isOpen * @see LineEvent */ void open(AudioFormat format) throws LineUnavailableException; /** * Reads audio data from the data line's input buffer. The requested number * of bytes is read into the specified array, starting at the specified * offset into the array in bytes. This method blocks until the requested * amount of data has been read. However, if the data line is closed, * stopped, drained, or flushed before the requested amount has been read, * the method no longer blocks, but returns the number of bytes read thus * far. *
* The number of bytes that can be read without blocking can be ascertained * using the {@link DataLine#available available} method of the * {@code DataLine} interface. (While it is guaranteed that this number of * bytes can be read without blocking, there is no guarantee that attempts * to read additional data will block.) *
* The number of bytes to be read must represent an integral number of
* sample frames, such that:
*
*