java.nio.ByteBuffer#allocate ( )源码实例Demo

public static byte[] serialize(TupleFilter rootFilter, Decorator decorator, IFilterCodeSystem<?> cs) {
    ByteBuffer buffer;
    int bufferSize = BUFFER_SIZE;
    while (true) {
        try {
            buffer = ByteBuffer.allocate(bufferSize);
            internalSerialize(rootFilter, decorator, buffer, cs);
            break;
        } catch (BufferOverflowException e) {
            if (bufferSize == (1 << 30))
                throw e;

            logger.info("Buffer size {} cannot hold the filter, resizing to 2 times", bufferSize);
            bufferSize = bufferSize << 1;
        }
    }
    byte[] result = new byte[buffer.position()];
    System.arraycopy(buffer.array(), 0, result, 0, buffer.position());
    return result;
}
 

/**
 * 编码：把业务消息包编码为可以发送的ByteBuffer
 */
@Override
public ByteBuffer encode(HelloPacket packet, GroupContext<Object, HelloPacket, Object> groupContext, ChannelContext<Object, HelloPacket, Object> channelContext)
{
	byte[] body = packet.getBody();
	int bodyLen = 0;
	if (body != null)
	{
		bodyLen = body.length;
	}

	int allLen = HelloPacket.HEADER_LENGHT + bodyLen;
	ByteBuffer buffer = ByteBuffer.allocate(allLen);
	buffer.order(groupContext.getByteOrder());

	buffer.putInt(bodyLen);

	if (body != null)
	{
		buffer.put(body);
	}
	return buffer;
}
 

@Override
public void writeObject(ByteBuffer buffer, Object object) throws IOException {
    if (!(object instanceof GZIPCompressedMessage)) return;
    Message message = ((GZIPCompressedMessage)object).getMessage();

    ByteBuffer tempBuffer = ByteBuffer.allocate(512000);
    Serializer.writeClassAndObject(tempBuffer, message);

    ByteArrayOutputStream byteArrayOutput = new ByteArrayOutputStream();
    GZIPOutputStream gzipOutput = new GZIPOutputStream(byteArrayOutput);

    tempBuffer.flip();
    gzipOutput.write(tempBuffer.array(), 0, tempBuffer.limit());
    gzipOutput.flush();
    gzipOutput.finish();
    gzipOutput.close();

    buffer.put(byteArrayOutput.toByteArray());
}
 

private HFileBlock getSampleHFileBlock(List<KeyValue> kvs, boolean useTag) {
  ByteBuffer keyValues = RedundantKVGenerator.convertKvToByteBuffer(kvs, includesMemstoreTS);
  int size = keyValues.limit();
  ByteBuffer buf = ByteBuffer.allocate(size + HConstants.HFILEBLOCK_HEADER_SIZE);
  buf.position(HConstants.HFILEBLOCK_HEADER_SIZE);
  keyValues.rewind();
  buf.put(keyValues);
  HFileContext meta = new HFileContextBuilder()
                      .withIncludesMvcc(includesMemstoreTS)
                      .withIncludesTags(useTag)
                      .withHBaseCheckSum(true)
                      .withCompression(Algorithm.NONE)
                      .withBlockSize(0)
                      .withChecksumType(ChecksumType.NULL)
                      .build();
  HFileBlock b = new HFileBlock(BlockType.DATA, size, size, -1, ByteBuff.wrap(buf),
      HFileBlock.FILL_HEADER, 0, 0, -1, meta, ByteBuffAllocator.HEAP);
  return b;
}
 

/**
 * The function to convert an array of bytes into a double number.
 *
 * @param bytes a double number represented by an array of bytes.
 * @return a number of the double type that is the conversion result.
 */
private double bytesToDouble(byte[] bytes) {
    ByteBuffer original = byteArrayToByteBuffer(bytes);

    if (bytes.length < BYTES_IN_DOUBLE) {
        ByteBuffer byteBuffer = ByteBuffer.allocate(BYTES_IN_DOUBLE);
        if (sasFileProperties.getEndianness() == 1) {
            byteBuffer.position(BYTES_IN_DOUBLE - bytes.length);
        }
        byteBuffer.put(original);
        byteBuffer.order(original.order());
        byteBuffer.position(0);
        original = byteBuffer;
    }

    return original.getDouble();
}
 

public Connection(SocketChannel channel, long lastContact) {
  this.channel = channel;
  this.lastContact = lastContact;
  this.data = null;
  this.dataLengthBuffer = ByteBuffer.allocate(4);
  this.unwrappedData = null;
  this.unwrappedDataLengthBuffer = ByteBuffer.allocate(4);
  this.socket = channel.socket();
  this.addr = socket.getInetAddress();
  if (addr == null) {
    this.hostAddress = "*Unknown*";
  } else {
    this.hostAddress = addr.getHostAddress();
  }
  this.remotePort = socket.getPort();
  this.responseQueue = new LinkedList<Call>();
  if (socketSendBufferSize != 0) {
    try {
      socket.setSendBufferSize(socketSendBufferSize);
    } catch (IOException e) {
      LOG.warn("Connection: unable to set socket send buffer size to " +
               socketSendBufferSize);
    }
  }
}
 

@Override
public byte[] getCacheKey()
{
  final ByteBuffer minCoordsBuffer = ByteBuffer.allocate(coords.length * Floats.BYTES);
  minCoordsBuffer.asFloatBuffer().put(coords);
  final byte[] minCoordsCacheKey = minCoordsBuffer.array();
  final ByteBuffer cacheKey = ByteBuffer
      .allocate(1 + minCoordsCacheKey.length + Ints.BYTES + Floats.BYTES)
      .put(minCoordsCacheKey)
      .putFloat(radius)
      .putInt(getLimit())
      .put(CACHE_TYPE_ID);
  return cacheKey.array();
}
 

@Test
public void test2() {
    String str = "abcde";
    ByteBuffer buf = ByteBuffer.allocate(1024);
    buf.put(str.getBytes());

    buf.flip();

    byte[] dst = new byte[buf.limit()];
    buf.get(dst, 0, 2);
    System.out.println(new String(dst, 0, 2));
    System.out.println(buf.position());

    // mark 标记position
    buf.mark();

    buf.get(dst,2,2);
    System.out.println(new String(dst, 0, 2));
    System.out.println(buf.position());

    //reset() : 恢复到 mark 的位置
    buf.reset();
    System.out.println(buf.position());

    //判断缓冲区中是否还有剩余数据
    if(buf.hasRemaining()){
        //获取缓冲区中可以操作的数量
        System.out.println(buf.remaining());
    }


}
 

protected ByteBuffer loadAtLocation(long loc)
  throws IOException
{
  if (loc == MAGIC_LOCATION_ZERO) return BB_ZERO;

  

  long file_t1 = System.nanoTime();

  long file_idx = loc / SEGMENT_FILE_SIZE;
  long in_file_loc = loc % SEGMENT_FILE_SIZE;
  ByteBuffer bb = null;
  try(FileChannel fc = getDataFileChannelRead(file_idx))
  {
    fc.position(in_file_loc);
    ByteBuffer lenbb = ByteBuffer.allocate(4);

    readBuffer(fc, lenbb);
    lenbb.rewind();


    int len = lenbb.getInt();

    byte[] buff = new byte[len];
    bb = ByteBuffer.wrap(buff);
    readBuffer(fc, bb);
    bb.rewind();
  }

  getTimeReport().addTime(System.nanoTime() - file_t1, "load_file");

  long t1 = System.nanoTime();
  ByteBuffer de_bb = decompress(bb);
  if (DEBUG) System.out.println("Decompress");
  getTimeReport().addTime(System.nanoTime() - t1, "decompress");
  return de_bb;

}
 

protected void setupTraps() {
    try (Keystone keystone = new Keystone(KeystoneArchitecture.Arm64, KeystoneMode.LittleEndian)) {
        unicorn.mem_map(LR, 0x10000, UnicornConst.UC_PROT_READ | UnicornConst.UC_PROT_EXEC);
        KeystoneEncoded encoded = keystone.assemble("b #0");
        byte[] b0 = encoded.getMachineCode();
        ByteBuffer buffer = ByteBuffer.allocate(0x10000);
        for (int i = 0; i < 0x10000; i += b0.length) {
            buffer.put(b0);
        }
        unicorn.mem_write(LR, buffer.array());
    }
}
 

public ByteBuffer newBufferHeadFirst(int size)
{
    if (head == null)
    {
        head = new LinkedList<ByteBuffer>();
    }
    ByteBuffer buf = ByteBuffer.allocate(size);
    head.addFirst(buf);
    return buf;
}
 

void init(final int length) {
    final int packet_length = length + HEADER_FOOTER_SIZE;
    data = ByteBuffer.allocate(packet_length);
    data.put(START_OF_MESSAGE);
    data.put((byte) packet_length);

}
 

@Test
public void testHeaderContinuationNonContiguous() throws Exception {
    // HTTP2 upgrade
    http2Connect();

    // Part 1
    byte[] frameHeader = new byte[9];
    ByteBuffer headersPayload = ByteBuffer.allocate(128);
    buildSimpleGetRequestPart1(frameHeader, headersPayload, 3);
    writeFrame(frameHeader, headersPayload);

    sendPing();

    handleGoAwayResponse(1,  Http2Error.COMPRESSION_ERROR);
}
 

@Override
public SendLog getOneSendLog(Query query) throws JoyQueueException {
    QueryCondition queryCondition = query.getQueryCondition();
    QueryCondition.RowKey rowKey = queryCondition.getRowKey();

    try {
        // 4 + 8 + 16 + 16
        ByteBuffer allocate = ByteBuffer.allocate(44);
        allocate.putInt(topicAppMapping.getTopicId(rowKey.getTopic()));
        allocate.putLong(rowKey.getTime());
        allocate.put(Md5.INSTANCE.encrypt(rowKey.getBusinessId().getBytes(Charset.forName("utf-8")), null));
        allocate.put(HBaseSerializer.hexStrToByteArray(rowKey.getMessageId()));
        // rowKey
        byte[] bytesRowKey = allocate.array();

        Pair<byte[], byte[]> bytes = hBaseClient.getKV(namespace, sendLogTable, cf, col, bytesRowKey);

        SendLog log = HBaseSerializer.readSendLog(bytes);

        StringBuilder clientIp = new StringBuilder();
        IpUtil.toAddress(log.getClientIp(), clientIp);
        log.setClientIpStr(clientIp.toString());

        String topicName = topicAppMapping.getTopicName(log.getTopicId());
        log.setTopic(topicName);

        String appName = topicAppMapping.getAppName(log.getAppId());
        log.setApp(appName);

        return log;
    } catch (Exception e) {
        throw new JoyQueueException(JoyQueueCode.SE_IO_ERROR, e);
    }
}
 

public static String readAllFromFile(Path path) {

        List<String> result = new ArrayList<>();
        try (SeekableByteChannel sbc = Files.newByteChannel(path)) {
            ByteBuffer buf = ByteBuffer.allocate(1024 * 128);
            while (sbc.read(buf) > 0) {
                buf.rewind();
                result.add(Charset.defaultCharset().decode(buf).toString());
                buf.flip();
            }
        } catch (IOException e) {
            ExcpReporting.LogError(fsys.class, e);
        }
        return String.join("\n", result);
    }
 

public byte[] exchange(byte tag, byte[] command) throws IOException {
   ByteArrayOutputStream response = new ByteArrayOutputStream();
   byte[] responseData = null;
   int offset = 0;
   int responseSize;
   if (debug) {
      Log.d(LOG_TAG, "=> " + Dump.dump(command));
   }
   command = helper.wrapCommandAPDU(tag, command, HID_BUFFER_SIZE);      
   UsbRequest requestWrite = new UsbRequest();
   if (!requestWrite.initialize(connection, out)) {
      throw new IOException();
   }
   while (offset != command.length) {
      int blockSize = (command.length - offset > HID_BUFFER_SIZE ? HID_BUFFER_SIZE : command.length - offset);
      System.arraycopy(command, offset, transferBuffer, 0, blockSize);
      if (debug) {
         Log.d(LOG_TAG, "wire => " + Dump.dump(transferBuffer));
      }
      if (!requestWrite.queue(ByteBuffer.wrap(transferBuffer), HID_BUFFER_SIZE)) {
         requestWrite.close();
         throw new IOException();
      }
      connection.requestWait();
      offset += blockSize;
   }
   ByteBuffer responseBuffer = ByteBuffer.allocate(HID_BUFFER_SIZE);
   UsbRequest requestRead = new UsbRequest();
   if (!requestRead.initialize(connection, in)) {
      requestRead.close();
      requestWrite.close();
      throw new IOException();
   }
   while ((responseData = helper.unwrapResponseAPDU(tag, response.toByteArray(), HID_BUFFER_SIZE)) == null) {
      responseBuffer.clear();
      if (!requestRead.queue(responseBuffer, HID_BUFFER_SIZE)) {
         requestRead.close();
         requestWrite.close();
         throw new IOException();
      }
      connection.requestWait();
      responseBuffer.rewind();
      responseBuffer.get(transferBuffer, 0, HID_BUFFER_SIZE);
      if (debug) {
         Log.d(LOG_TAG, "wire <= " + Dump.dump(transferBuffer));
      }
      response.write(transferBuffer, 0, HID_BUFFER_SIZE);
   }
   if (debug) {
      Log.d(LOG_TAG, "<= " + Dump.dump(responseData));
   }

   requestWrite.close();
   requestRead.close();
   return responseData;
}
 

/**
 * Tests an search request decode with a simple equality match filter.
 */
@Test
public void testDecodeSearchRequestExtensibleMatch() throws DecoderException, EncoderException, LdapException
{

    ByteBuffer stream = ByteBuffer.allocate( 0x63 );
    stream.put( new byte[]
        {
            0x30, 0x61,                         // LDAPMessage ::= SEQUENCE {
              0x02, 0x01, 0x01,                 // messageID
              0x63, 0x5C,                       //   protocolOp      CHOICE {
                                                //     searchRequest   SearchRequest,
                                                //
                                                // SearchRequest ::= [APPLICATION 3] SEQUENCE {
                0x04, 0x11,                     // "dc=example,dc=com"
                  'd', 'c', '=', 'e', 'x', 'a', 'm', 'p', 'l', 'e', ',', 'd', 'c', '=', 'c', 'o', 'm',
                                                //   scope           ENUMERATED {
                0x0A, 0x01, 0x00,               //      baseObject              (0), ...
                                                //   derefAliases    ENUMERATED {
                0x0A, 0x01, 0x02,               //     derefFindingBaseObj     (2),...
                0x02, 0x01, 0x02,               //   sizeLimit       INTEGER (0 .. maxInt), (2)
                0x02, 0x01, 0x03,               //   timeLimit       INTEGER (0 .. maxInt), (3)
                0x01, 0x01, ( byte ) 0xFF,      //   typesOnly       BOOLEAN, (true)
                ( byte ) 0xA9, 0x21,            //   filter          Filter,
                                                //
                                                // Filter ::= CHOICE {
                                                //   extensibleMatch [9] MatchingRuleAssertion }
                                                //
                                                // MatchingRuleAssertion ::= SEQUENCE {
                  ( byte ) 0x81, 0x13,          //    matchingRule    [1] MatchingRuleId OPTIONAL,
                    '1', '.', '2', '.', '8', '4', '0', '.', '4', '8', '0', '1', '8', '.', '1', '.', '2', '.', '2',
                  ( byte ) 0x82, 0x02,          //    type            [2] AttributeDescription OPTIONAL,
                    'c', 'n',
                  ( byte ) 0x83, 0x03,          //    matchValue      [3] AssertionValue,
                    'a', 'o', 'k',
                                                //    dnAttributes    [4] BOOLEAN DEFAULT FALSE  }
                  ( byte ) 0x84, 0x01, ( byte ) 0xFF,
                0x30, 0x15,                     // AttributeDescriptionList ::= SEQUENCE OF AttributeDescription
                  0x04, 0x05,
                    'a', 't', 't', 'r', '0',    // AttributeDescription ::= LDAPString
                  0x04, 0x05,
                    'a', 't', 't', 'r', '1',    // AttributeDescription ::= LDAPString
                  0x04, 0x05,
                    'a', 't', 't', 'r', '2',    // AttributeDescription ::= LDAPString
        });

    stream.flip();

    // Allocate a BindRequest Container
    LdapMessageContainer<SearchRequest> ldapMessageContainer = new LdapMessageContainer<>( codec );

    Asn1Decoder.decode( stream, ldapMessageContainer );

    SearchRequest searchRequest = ldapMessageContainer.getMessage();

    assertEquals( 1, searchRequest.getMessageId() );
    assertEquals( "dc=example,dc=com", searchRequest.getBase().toString() );
    assertEquals( SearchScope.OBJECT, searchRequest.getScope() );
    assertEquals( AliasDerefMode.DEREF_FINDING_BASE_OBJ, searchRequest.getDerefAliases() );
    assertEquals( 2, searchRequest.getSizeLimit() );
    assertEquals( 3, searchRequest.getTimeLimit() );
    assertEquals( true, searchRequest.getTypesOnly() );

    // The attributes
    List<String> attributes = searchRequest.getAttributes();

    for ( String attribute : attributes )
    {
        assertNotNull( attribute );
    }

    // Check encode reverse
    Asn1Buffer buffer = new Asn1Buffer();

    LdapEncoder.encodeMessage( buffer, codec, searchRequest );

    assertArrayEquals( stream.array(), buffer.getBytes().array() );
}
 

private void acceptIncomingSocketConnection(final Socket socket) throws IOException {
    Log.d(Config.LOGTAG, "accepted connection from " + socket.getInetAddress().getHostAddress());
    socket.setSoTimeout(SOCKET_TIMEOUT_DIRECT);
    final byte[] authBegin = new byte[2];
    final InputStream inputStream = socket.getInputStream();
    final OutputStream outputStream = socket.getOutputStream();
    inputStream.read(authBegin);
    if (authBegin[0] != 0x5) {
        socket.close();
    }
    final short methodCount = authBegin[1];
    final byte[] methods = new byte[methodCount];
    inputStream.read(methods);
    if (SocksSocketFactory.contains((byte) 0x00, methods)) {
        outputStream.write(new byte[]{0x05, 0x00});
    } else {
        outputStream.write(new byte[]{0x05, (byte) 0xff});
    }
    byte[] connectCommand = new byte[4];
    inputStream.read(connectCommand);
    if (connectCommand[0] == 0x05 && connectCommand[1] == 0x01 && connectCommand[3] == 0x03) {
        int destinationCount = inputStream.read();
        final byte[] destination = new byte[destinationCount];
        inputStream.read(destination);
        final byte[] port = new byte[2];
        inputStream.read(port);
        final String receivedDestination = new String(destination);
        final ByteBuffer response = ByteBuffer.allocate(7 + destination.length);
        final byte[] responseHeader;
        final boolean success;
        if (receivedDestination.equals(this.destination) && this.socket == null) {
            responseHeader = new byte[]{0x05, 0x00, 0x00, 0x03};
            success = true;
        } else {
            Log.d(Config.LOGTAG, this.account.getJid().asBareJid() + ": destination mismatch. received " + receivedDestination + " (expected " + this.destination + ")");
            responseHeader = new byte[]{0x05, 0x04, 0x00, 0x03};
            success = false;
        }
        response.put(responseHeader);
        response.put((byte) destination.length);
        response.put(destination);
        response.put(port);
        outputStream.write(response.array());
        outputStream.flush();
        if (success) {
            Log.d(Config.LOGTAG, this.account.getJid().asBareJid() + ": successfully processed connection to candidate " + candidate.getHost() + ":" + candidate.getPort());
            socket.setSoTimeout(0);
            this.socket = socket;
            this.inputStream = inputStream;
            this.outputStream = outputStream;
            this.isEstablished = true;
            FileBackend.close(serverSocket);
        } else {
            FileBackend.close(socket);
        }
    } else {
        socket.close();
    }
}
 

@Override
public int processNextFrame() {
    if (lastResult == RESULT_EOS_REACHED) {
        // we are done
        return lastResult;
    }

    // TranscoderJob expects the first result to be RESULT_OUTPUT_MEDIA_FORMAT_CHANGED, so that it can start the mediaMuxer
    if (!targetTrackAdded) {
        targetFormat = mediaSource.getTrackFormat(sourceTrack);
        if (duration > 0) {
            targetFormat.setLong(MediaFormat.KEY_DURATION, duration);
        }

        targetTrack = mediaMuxer.addTrack(targetFormat, targetTrack);
        targetTrackAdded = true;

        int bufferSize = targetFormat.getInteger(MediaFormat.KEY_MAX_INPUT_SIZE);
        outputBuffer = ByteBuffer.allocate(bufferSize);

        lastResult = RESULT_OUTPUT_MEDIA_FORMAT_CHANGED;
        return lastResult;
    }

    int selectedTrack = mediaSource.getSampleTrackIndex();
    if (selectedTrack != NO_SELECTED_TRACK && selectedTrack != sourceTrack) {
        lastResult = RESULT_FRAME_PROCESSED;
        return lastResult;
    }

    lastResult = RESULT_FRAME_PROCESSED;

    int bytesRead = mediaSource.readSampleData(outputBuffer, 0);
    if (bytesRead > 0) {
        int outputFlags = 0;
        long sampleTime = mediaSource.getSampleTime();
        int inputFlags = mediaSource.getSampleFlags();

        if ((inputFlags & MediaExtractor.SAMPLE_FLAG_SYNC) != 0) {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                outputFlags = MediaCodec.BUFFER_FLAG_KEY_FRAME;
            } else {
                outputFlags = MediaCodec.BUFFER_FLAG_SYNC_FRAME;
            }
        }
        if (duration > 0) {
            progress = ((float) sampleTime) / duration;
        }
        outputBufferInfo.set(0, bytesRead, sampleTime, outputFlags);
        mediaMuxer.writeSampleData(targetTrack, outputBuffer, outputBufferInfo);
        mediaSource.advance();
    } else {
        outputBuffer.clear();
        progress = 1.0f;
        lastResult = RESULT_EOS_REACHED;
        Log.d(TAG, "Reach EoS on input stream");
    }

    return lastResult;
}
 

@Override
public String telnet(Channel channel, String message) {
    long size = 0;
    File file = LoggerFactory.getFile();
    StringBuffer buf = new StringBuffer();
    if (message == null || message.trim().length() == 0) {
        buf.append("EXAMPLE: log error / log 100");
    } else {
        String str[] = message.split(" ");
        if (!StringUtils.isInteger(str[0])) {
            LoggerFactory.setLevel(Level.valueOf(message.toUpperCase()));
        } else {
            int SHOW_LOG_LENGTH = Integer.parseInt(str[0]);

            if (file != null && file.exists()) {
                try {
                    FileInputStream fis = new FileInputStream(file);
                    FileChannel filechannel = fis.getChannel();
                    size = filechannel.size();
                    ByteBuffer bb;
                    if (size <= SHOW_LOG_LENGTH) {
                        bb = ByteBuffer.allocate((int) size);
                        filechannel.read(bb, 0);
                    } else {
                        int pos = (int) (size - SHOW_LOG_LENGTH);
                        bb = ByteBuffer.allocate(SHOW_LOG_LENGTH);
                        filechannel.read(bb, pos);
                    }
                    bb.flip();
                    String content = new String(bb.array()).replace("<", "&lt;")
                            .replace(">", "&gt;").replace("\n", "<br/><br/>");
                    buf.append("\r\ncontent:" + content);

                    buf.append("\r\nmodified:" + (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss")
                            .format(new Date(file.lastModified()))));
                    buf.append("\r\nsize:" + size + "\r\n");
                } catch (Exception e) {
                    buf.append(e.getMessage());
                }
            } else {
                size = 0;
                buf.append("\r\nMESSAGE: log file not exists or log appender is console .");
            }
        }
    }
    buf.append("\r\nCURRENT LOG LEVEL:" + LoggerFactory.getLevel())
            .append("\r\nCURRENT LOG APPENDER:" + (file == null ? "console" : file.getAbsolutePath()));
    return buf.toString();
}