Example usage for java.nio ByteBuffer flip

List of usage examples for java.nio ByteBuffer flip

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Introduction

In this page you can find the example usage for java.nio ByteBuffer flip.

Prototype

public final Buffer flip()

Source Link

Document

Flips this buffer.

Usage

From source file:com.sunchenbin.store.feilong.core.io.IOWriteUtil.java

/**
 * NIO API ?? ()./*from  w ww . j  a v  a 2s  .c o m*/
 * 
 * <h3>NIO</h3>
 * 
 * <blockquote>
 * <p>
 * nionew io,jdk1.4,??<br>
 * nio??<br>
 * </p>
 * 
 * <p>
 * ??,<br>
 * ?,,??? ????cpu,?cpu? <br>
 * ? Java IO ,? IO,NIO ?? IO
 * </p>
 * 
 * <p>
 * The new I/O (NIO) APIs introduced in v 1.4 provide new features and improved performance in the areas of buffer management, scalable
 * network and file I/O, character-set support, and regular-expression matching. The NIO APIs supplement the I/O facilities in the
 * java.io package.
 * </p>
 * 
 * <p>
 * The NIO APIs include the following features:
 * </p>
 * 
 * <ol>
 * <li>Buffers for data of primitive types</li>
 * <li>Character-set encoders and decoders</li>
 * <li>A pattern-matching facility based on Perl-style regular expressions</li>
 * <li>Channels, a new primitive I/O abstraction</li>
 * <li>A file interface that supports locks and memory mapping</li>
 * <li>A multiplexed, non-blocking I/O facility for writing scalable servers</li>
 * </ol>
 * </blockquote>
 * 
 * <p>
 * As creme de la creme with regard to performance,you could use NIO {@link java.nio.channels.Channels} and {@link java.nio.ByteBuffer}.
 * </p>
 *
 * @param bufferLength
 *            the buffer length
 * @param inputStream
 *            the input stream
 * @param outputStream
 *            the output stream
 * @since 1.0.8
 * @since jdk1.4
 */
private static void writeUseNIO(int bufferLength, InputStream inputStream, OutputStream outputStream) {
    Date beginDate = new Date();
    ReadableByteChannel readableByteChannel = Channels.newChannel(inputStream);
    WritableByteChannel writableByteChannel = Channels.newChannel(outputStream);
    ByteBuffer byteBuffer = ByteBuffer.allocate(bufferLength);

    try {
        int loopCount = 0;
        int sumSize = 0;
        while (readableByteChannel.read(byteBuffer) != -1) {
            byteBuffer.flip();
            sumSize += writableByteChannel.write(byteBuffer);
            byteBuffer.clear();
            loopCount++;
        }
        if (LOGGER.isDebugEnabled()) {
            String formatSize = FileUtil.formatSize(sumSize);
            String time = DateExtensionUtil.getIntervalForView(beginDate, new Date());
            LOGGER.debug("Write data over,sumSize:[{}],bufferLength:[{}],loopCount:[{}],time:{}", formatSize,
                    bufferLength, loopCount, time);
        }
    } catch (IOException e) {
        throw new UncheckedIOException(e);
    } finally {
        IOUtils.closeQuietly(outputStream);
        IOUtils.closeQuietly(writableByteChannel);
        IOUtils.closeQuietly(inputStream);
        IOUtils.closeQuietly(readableByteChannel);
    }
}

From source file:com.feilong.commons.core.io.IOWriteUtil.java

/**
 * NIO API ?? ()./*  ww  w  . j av  a  2 s.c  o m*/
 *
 * @param bufferLength
 *            the buffer length
 * @param inputStream
 *            the input stream
 * @param outputStream
 *            the output stream
 * @throws UncheckedIOException
 *             the unchecked io exception
 * @since 1.0.8
 */
private static void writeUseNIO(int bufferLength, InputStream inputStream, OutputStream outputStream)
        throws UncheckedIOException {
    int i = 0;
    int sumSize = 0;
    int j = 0;

    ///2 
    //As creme de la creme with regard to performance, you could use NIO Channels and ByteBuffer. 

    ReadableByteChannel readableByteChannel = Channels.newChannel(inputStream);
    WritableByteChannel writableByteChannel = Channels.newChannel(outputStream);

    ByteBuffer byteBuffer = ByteBuffer.allocate(bufferLength);

    try {
        while (readableByteChannel.read(byteBuffer) != -1) {
            byteBuffer.flip();
            j = writableByteChannel.write(byteBuffer);
            sumSize += j;
            byteBuffer.clear();
            i++;
        }

        if (log.isDebugEnabled()) {
            log.debug("Write data over,sumSize:[{}],bufferLength:[{}],loopCount:[{}]",
                    FileUtil.formatSize(sumSize), bufferLength, i);
        }
    } catch (IOException e) {
        throw new UncheckedIOException(e);
    } finally {
        try {
            if (writableByteChannel != null) {
                outputStream.close();
                writableByteChannel.close();
            }
            if (readableByteChannel != null) {
                inputStream.close();
                readableByteChannel.close();
            }
        } catch (IOException e) {
            throw new UncheckedIOException(e);
        }
    }
}

From source file:com.chicm.cmraft.rpc.PacketUtils.java

public static RpcCall parseRpcRequestFromChannel(AsynchronousSocketChannel channel, BlockingService service)
        throws InterruptedException, ExecutionException, IOException {
    RpcCall call = null;//w  w w .j  a va 2  s.  c  om
    long t = System.currentTimeMillis();
    InputStream in = Channels.newInputStream(channel);
    byte[] datasize = new byte[MESSAGE_LENGHT_FIELD_SIZE];
    in.read(datasize);
    int nDataSize = bytes2Int(datasize);

    int len = 0;
    ByteBuffer buf = ByteBuffer.allocateDirect(nDataSize);
    for (; len < nDataSize;) {
        len += channel.read(buf).get();
    }
    if (len < nDataSize) {
        LOG.error("SOCKET READ FAILED, len:" + len);
        return call;
    }
    byte[] data = new byte[nDataSize];
    buf.flip();
    buf.get(data);
    int offset = 0;
    CodedInputStream cis = CodedInputStream.newInstance(data, offset, nDataSize - offset);
    int headerSize = cis.readRawVarint32();
    offset += cis.getTotalBytesRead();
    RequestHeader header = RequestHeader.newBuilder().mergeFrom(data, offset, headerSize).build();

    offset += headerSize;
    cis.skipRawBytes(headerSize);
    cis.resetSizeCounter();
    int bodySize = cis.readRawVarint32();
    offset += cis.getTotalBytesRead();
    //LOG.debug("header parsed:" + header.toString());

    MethodDescriptor md = service.getDescriptorForType().findMethodByName(header.getRequestName());
    Builder builder = service.getRequestPrototype(md).newBuilderForType();
    Message body = null;
    if (builder != null) {
        body = builder.mergeFrom(data, offset, bodySize).build();
        //LOG.debug("server : request parsed:" + body.toString());
    }
    call = new RpcCall(header.getId(), header, body, md);
    if (LOG.isTraceEnabled()) {
        LOG.trace("Parse Rpc request from socket: " + call.getCallId() + ", takes"
                + (System.currentTimeMillis() - t) + " ms");
    }

    return call;
}

From source file:com.chicm.cmraft.rpc.PacketUtils.java

public static RpcCall parseRpcResponseFromChannel(AsynchronousSocketChannel channel, BlockingService service)
        throws InterruptedException, ExecutionException, IOException {
    RpcCall call = null;/*from  w w w  .  j  a va  2  s . c o m*/
    long t = System.currentTimeMillis();
    InputStream in = Channels.newInputStream(channel);
    byte[] datasize = new byte[MESSAGE_LENGHT_FIELD_SIZE];
    in.read(datasize);
    int nDataSize = bytes2Int(datasize);

    LOG.debug("message size: " + nDataSize);

    int len = 0;
    ByteBuffer buf = ByteBuffer.allocateDirect(nDataSize);
    for (; len < nDataSize;) {
        len += channel.read(buf).get();
    }
    if (len < nDataSize) {
        LOG.error("SOCKET READ FAILED, len:" + len);
        return call;
    }
    byte[] data = new byte[nDataSize];
    buf.flip();
    buf.get(data);
    int offset = 0;
    CodedInputStream cis = CodedInputStream.newInstance(data, offset, nDataSize - offset);
    int headerSize = cis.readRawVarint32();
    offset += cis.getTotalBytesRead();
    ResponseHeader header = ResponseHeader.newBuilder().mergeFrom(data, offset, headerSize).build();

    offset += headerSize;
    cis.skipRawBytes(headerSize);
    cis.resetSizeCounter();
    int bodySize = cis.readRawVarint32();
    offset += cis.getTotalBytesRead();

    MethodDescriptor md = service.getDescriptorForType().findMethodByName(header.getResponseName());
    Builder builder = service.getResponsePrototype(md).newBuilderForType();
    Message body = null;
    if (builder != null) {
        body = builder.mergeFrom(data, offset, bodySize).build();
    }
    call = new RpcCall(header.getId(), header, body, md);
    if (LOG.isTraceEnabled()) {
        LOG.trace("Parse Rpc response from socket: " + call.getCallId() + ", takes"
                + (System.currentTimeMillis() - t) + " ms");
    }

    return call;
}

From source file:com.flexive.shared.FxFileUtils.java

/**
 * Copy data from source to destination nio channel
 *
 * @param source      source channel//from  w  w w . j  av  a2  s.  c  o m
 * @param destination destination channel
 * @return total number of bytes copied
 * @throws java.io.IOException on errors
 */
public static long copyNIOChannel(ReadableByteChannel source, WritableByteChannel destination)
        throws IOException {
    ByteBuffer xferBuffer = ByteBuffer.allocateDirect(4096);
    long count = 0, read, written;
    while (true) {
        read = source.read(xferBuffer);
        if (read < 0)
            return count;
        xferBuffer.flip();
        written = destination.write(xferBuffer);
        if (written > 0) {
            count += written;
            if (xferBuffer.hasRemaining())
                xferBuffer.compact();
            else
                xferBuffer.clear();
        } else {
            while (xferBuffer.hasRemaining()) {
                try {
                    Thread.sleep(5);
                } catch (InterruptedException e) {
                    LOG.warn(e);
                }
                written = destination.write(xferBuffer);
                if (written > 0) {
                    count += written;
                    if (xferBuffer.hasRemaining())
                        xferBuffer.compact();
                }
            }
            if (!xferBuffer.hasRemaining())
                xferBuffer.clear();
        }
    }
}

From source file:cn.tc.ulife.platform.msg.http.util.HttpUtil.java

/**
 * ??/*from  ww w . j av  a  2s.  c o m*/
 *
 * @param is
 * @return
 * @throws IOException
 */
public static String readStreamAsStr(InputStream is) throws IOException {
    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    WritableByteChannel dest = Channels.newChannel(bos);
    ReadableByteChannel src = Channels.newChannel(is);
    ByteBuffer bb = ByteBuffer.allocate(4096);

    while (src.read(bb) != -1) {
        bb.flip();
        dest.write(bb);
        bb.clear();
    }
    src.close();
    dest.close();

    return new String(bos.toByteArray(), Constants.ENCODING);
}

From source file:org.apache.cassandra.db.index.sasi.disk.TokenTreeTest.java

private static DecoratedKey dk(Long token) {
    ByteBuffer buf = ByteBuffer.allocate(8);
    buf.putLong(token);/*w  w w.j  av  a2s  .c o  m*/
    buf.flip();
    Long hashed = MurmurHash.hash2_64(buf, buf.position(), buf.remaining(), 0);
    return new DecoratedKey(new LongToken(hashed), buf);
}

From source file:org.apache.xmlgraphics.util.io.Base64Test.java

/**
 * Returns true if the contents of <tt>is1</tt> match the contents of
 * <tt>is2</tt>/*from  www  .  ja  va  2  s .  c o  m*/
 *
 * @throws IOException
 */
public static boolean compareStreams(final InputStream i1, final InputStream i2, final boolean skipws)
        throws IOException {
    try (final ReadableByteChannel ch1 = Channels.newChannel(i1)) {
        try (final ReadableByteChannel ch2 = Channels.newChannel(i2)) {

            final ByteBuffer buf1 = ByteBuffer.allocateDirect(1024);
            final ByteBuffer buf2 = ByteBuffer.allocateDirect(1024);

            while (true) {

                final int n1 = ch1.read(buf1);
                final int n2 = ch2.read(buf2);

                if (n1 == -1 || n2 == -1) {
                    return n1 == n2;
                }

                buf1.flip();
                buf2.flip();

                for (int i = 0; i < Math.min(n1, n2); ++i) {
                    if (buf1.get() != buf2.get()) {
                        return false;
                    }
                }

                buf1.compact();
                buf2.compact();
            }
        }
    }
}

From source file:com.gamesalutes.utils.ByteUtils.java

/**
 * Returns a <code>ByteBuffer</code> containing the byte representation
 * of the serializable object <code>obj</code>.
 * // w ww .j a va2 s . c  om
 * @param obj the <code>Object</code> to convert to its byte representation
 * @param buf an existing buffer to use for storage or <code>null</code> to create new buffer.
 *        If <code>buf</code> is not large enough it will be expanded using {@link #growBuffer(ByteBuffer, int)}
 * @return <code>ByteBuffer</code> containing the byte representation
 * of <code>obj</code>.
 * 
 * @throws IOException if <code>obj</code> is not serializable or error occurs while writing the bytes
 */
public static ByteBuffer getObjectBytes(Object obj, ByteBuffer buf) throws IOException {
    if (buf == null)
        buf = ByteBuffer.allocate(READ_BUFFER_SIZE);

    // note the input position
    int startPos = buf.position();
    ByteBufferChannel channel = new ByteBufferChannel(buf);
    ObjectOutputStream out = null;
    try {
        out = new ObjectOutputStream(Channels.newOutputStream(channel));
        out.writeObject(obj);
        out.flush();
    } finally {
        MiscUtils.closeStream(out);
    }

    ByteBuffer returnBuf = channel.getByteBuffer();
    returnBuf.flip();
    // reset starting position to be that of input buffer
    returnBuf.position(startPos);
    return returnBuf;
}

From source file:it.geosolutions.tools.io.file.IOUtils.java

/**
 * Copies the content of the source channel onto the destination channel.
 * /*from   w w w. java 2s . c  o m*/
 * @param bufferSize
 *            size of the temp buffer to use for this copy.
 * @param source
 *            the source {@link ReadableByteChannel}.
 * @param destination
 *            the destination {@link WritableByteChannel};.
 * @throws IOException
 *             in case something bad happens.
 */
public static void copyChannel(int bufferSize, ReadableByteChannel source, WritableByteChannel destination)
        throws IOException {

    Objects.notNull(source, destination);
    if (!source.isOpen() || !destination.isOpen())
        throw new IllegalStateException("Source and destination channels must be open.");

    final java.nio.ByteBuffer buffer = java.nio.ByteBuffer.allocateDirect(bufferSize);
    while (source.read(buffer) != -1) {
        // prepare the buffer for draining
        buffer.flip();

        // write to destination
        while (buffer.hasRemaining())
            destination.write(buffer);

        // clear
        buffer.clear();

    }

}