Java tutorial
//package com.java2s; /* * Copyright 1999-2012 Luca Garulli (l.garulli--at--orientechnologies.com) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.nio.ByteBuffer; public class Main { public static final int SIZE_OF_LONG = 8; private static final int SIZE_OF_BYTE_IN_BITS = 8; private static final int MASK = 0x000000FF; /** * Merge long value from two byte buffer. First bytes of long will be extracted from first byte buffer and second from second one. * How many bytes will be read from first buffer determines based on <code>buffer.remaining()</code> value * * @param buffer * to read first part of value * @param buffer1 * to read second part of value * @return merged value */ public static long mergeLongFromBuffers(ByteBuffer buffer, ByteBuffer buffer1) { long result = 0; int remaining = buffer.remaining(); for (int i = 0; i < remaining; ++i) { result = result | (MASK & buffer.get()); result = result << SIZE_OF_BYTE_IN_BITS; } for (int i = 0; i < SIZE_OF_LONG - remaining - 1; ++i) { result = result | (MASK & buffer1.get()); result = result << SIZE_OF_BYTE_IN_BITS; } result = result | (MASK & buffer1.get()); return result; } }