Java InputStreamWrapper.available方法代码示例

import org.hsqldb.lib.InputStreamWrapper; //导入方法依赖的package包/类
/**
 * After instantiating a TarEntrySupplicant, the user must either invoke
 * write() or close(), to release system resources on the input
 * File/Stream.
 * <P>
 * <B>WARNING:</B>
 * Do not use this method unless the quantity of available RAM is
 * sufficient to accommodate the specified maxBytes all at one time.
 * This constructor loads all input from the specified InputStream into
 * RAM before anything is written to disk.
 * </P>
 *
 * @param maxBytes This method will fail if more than maxBytes bytes
 *                 are supplied on the specified InputStream.
 *                 As the type of this parameter enforces, the max
 *                 size you can request is 2GB.
 */
public TarEntrySupplicant(String path, InputStream origStream,
                          int maxBytes, char typeFlag,
                          TarFileOutputStream tarStream)
        throws IOException, TarMalformatException {

    /*
     * If you modify this, make sure to not intermix reading/writing of
     * the PipedInputStream and the PipedOutputStream, or you could
     * cause dead-lock.  Everything is safe if you close the
     * PipedOutputStream before reading the PipedInputStream.
     */
    this(path, typeFlag, tarStream, 0100000000000L);

    if (maxBytes < 1) {
        throw new IllegalArgumentException(RB.read_lt_1.getString());
    }

    int               i;
    PipedOutputStream outPipe = new PipedOutputStream();

    /*
     *  This constructor not available until Java 1.6:
     * inputStream = new PipedInputStream(outPipe, maxBytes);
     */
    try {
        inputStream =
            new InputStreamWrapper(new PipedInputStream(outPipe));

        while ((i =
                origStream.read(tarStream.writeBuffer, 0,
                                tarStream.writeBuffer.length)) > 0) {
            outPipe.write(tarStream.writeBuffer, 0, i);
        }

        outPipe.flush();    // Do any good on a pipe?
        dataSize = inputStream.available();

        if (TarFileOutputStream.debug) {
            System.out.println(
                RB.stream_buffer_report.getString(
                    Long.toString(dataSize)));
        }
    } catch (IOException ioe) {
        close();

        throw ioe;
    } finally {
        try {
            outPipe.close();
        } finally {
            outPipe = null;    // Encourage buffer GC
        }
    }

    modTime = new java.util.Date().getTime() / 1000L;
}