Java tutorial
/* * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 which accompanies this distribution, * and is available at http://www.eclipse.org/legal/epl-v10.html */ package org.opendaylight.protocol.util; import com.google.common.base.Preconditions; import io.netty.buffer.ByteBuf; import java.math.BigInteger; import java.util.BitSet; import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IetfInetUtil; import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv4Address; import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv4Prefix; import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv6Address; import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.Ipv6Prefix; import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.ieee754.rev130819.Float32; /** * Utility class for ByteBuf's write methods. */ public final class ByteBufWriteUtil { public static final int SHORT_BYTES_LENGTH = Short.SIZE / Byte.SIZE; public static final int MEDIUM_BYTES_LENGTH = 3; public static final int INT_BYTES_LENGTH = Integer.SIZE / Byte.SIZE; public static final int LONG_BYTES_LENGTH = Long.SIZE / Byte.SIZE; public static final int FLOAT32_BYTES_LENGTH = INT_BYTES_LENGTH; public static final int ONE_BYTE_LENGTH = 1; public static final int IPV4_PREFIX_BYTE_LENGTH = Ipv4Util.IP4_LENGTH + 1; public static final int IPV6_PREFIX_BYTE_LENGTH = Ipv6Util.IPV6_LENGTH + 1; private ByteBufWriteUtil() { throw new UnsupportedOperationException(); } /** * Writes 32-bit integer <code>value</code> if not null, otherwise writes * zeros to the <code>output</code> ByteBuf. ByteBuf's writerIndex is * increased by 4. * * @param value * Integer value to be written to the output. * @param output * ByteBuf, where value or zeros are written. */ public static void writeInt(final Integer value, final ByteBuf output) { if (value != null) { output.writeInt(value); } else { output.writeZero(INT_BYTES_LENGTH); } } /** * Writes 24-bit integer <code>value</code> if not null, otherwise writes * zeros to the <code>output</code> ByteBuf. ByteBuf's writerIndex is * increased by 3. * * @param value * Medium value to be written to the output. * @param output * ByteBuf, where value or zeros are written. */ public static void writeMedium(final Integer value, final ByteBuf output) { if (value != null) { output.writeMedium(value); } else { output.writeZero(MEDIUM_BYTES_LENGTH); } } /** * Writes 16-bit short <code>value</code> if not null, otherwise writes * zeros to the <code>output</code> ByteBuf. ByteBuf's writerIndex is * increased by 2. * * @param value * Short value to be written to the output. * @param output * ByteBuf, where value or zeros are written. */ public static void writeShort(final Short value, final ByteBuf output) { if (value != null) { output.writeShort(value); } else { output.writeZero(SHORT_BYTES_LENGTH); } } /** * Writes 64-bit long <code>value</code> if not null, otherwise writes zeros * to the <code>output</code> ByteBuf. ByteBuf's writerIndex is increased by * 8. * * @param value * Long value to be written to the output. * @param output * ByteBuf, where value or zeros are written. */ public static void writeLong(final Long value, final ByteBuf output) { if (value != null) { output.writeLong(value); } else { output.writeZero(LONG_BYTES_LENGTH); } } /** * Writes boolean <code>value</code> if not null, otherwise writes zero to * the <code>output</code> ByteBuf. ByteBuf's writerIndex is increased by 1. * * @param value * Boolean value to be written to the output. * @param output * ByteBuf, where value or zero is written. */ public static void writeBoolean(final Boolean value, final ByteBuf output) { if (value != null) { output.writeBoolean(value); } else { output.writeZero(ONE_BYTE_LENGTH); } } /** * Writes unsigned byte <code>value</code> if not null, otherwise writes * zero to the <code>output</code> ByteBuf. ByteBuf's writerIndex is * increased by 1. * * @param value * Short value to be write to the output. * @param output * ByteBuf, where value or zeros are written. */ public static void writeUnsignedByte(final Short value, final ByteBuf output) { if (value != null) { output.writeByte(value); } else { output.writeZero(ONE_BYTE_LENGTH); } } /** * Writes unsigned 16-bit short integer <code>value</code> if not null, * otherwise writes zeros to the <code>output</code> ByteBuf. ByteBuf's * writerIndex is increased by 2. * * @param value * Integer value to be written to the output. * @param output * ByteBuf, where value or zeros are written. */ public static void writeUnsignedShort(final Integer value, final ByteBuf output) { if (value != null) { output.writeShort(value.shortValue()); } else { output.writeZero(SHORT_BYTES_LENGTH); } } /** * Writes unsigned 32-bit integer <code>value</code> if not null, otherwise * writes zeros to the <code>output</code> ByteBuf. ByteBuf's writerIndex is * increased by 4. * * @param value * Long value to be written to the output. * @param output * ByteBuf, where value or zeros are written. */ public static void writeUnsignedInt(final Long value, final ByteBuf output) { if (value != null) { output.writeInt(value.intValue()); } else { output.writeZero(INT_BYTES_LENGTH); } } /** * Writes unsigned 64-bit integer <code>value</code> if not null, otherwise * writes zeros to the <code>output</code> ByteBuf. ByteBuf's writerIndex is * increased by 8. * * @param value * BigInteger value to be written to the output. * @param output * ByteBuf, where value or zeros are written. */ public static void writeUnsignedLong(final BigInteger value, final ByteBuf output) { if (value != null) { output.writeLong(value.longValue()); } else { output.writeZero(LONG_BYTES_LENGTH); } } /** * Writes IPv4 address if not null, otherwise writes zeros to the * <code>output</code> ByteBuf. ByteBuf's writerIndex is increased by 4. * * @param ipv4Address * IPv4 address to be written to the output. * @param output * ByteBuf, where ipv4Address or zeros are written. */ public static void writeIpv4Address(final Ipv4Address ipv4Address, final ByteBuf output) { if (ipv4Address != null) { output.writeBytes(Ipv4Util.bytesForAddress(ipv4Address)); } else { output.writeZero(Ipv4Util.IP4_LENGTH); } } /** * Writes IPv4 prefix if not null, otherwise writes zeros to the * <code>output</code> ByteBuf. ByteBuf's writerIndex is increased by 5. * * @param ipv4Prefix * IPv4 prefix value to be written to the output. Prefix is * written in the last byte. * @param output * ByteBuf, where ipv4Prefix or zeros are written. */ public static void writeIpv4Prefix(final Ipv4Prefix ipv4Prefix, final ByteBuf output) { if (ipv4Prefix != null) { output.writeBytes(Ipv4Util.bytesForPrefix(ipv4Prefix)); } else { output.writeZero(IPV4_PREFIX_BYTE_LENGTH); } } /** * Writes IPv6 address if not null, otherwise writes zeros to the * <code>output</code> ByteBuf. ByteBuf's writerIndex is increased by 16. * * @param ipv6Address * IPv6 address to be written to the output. * @param output * ByteBuf, where ipv6Address or zeros are written. */ public static void writeIpv6Address(final Ipv6Address ipv6Address, final ByteBuf output) { if (ipv6Address != null) { output.writeBytes(Ipv6Util.bytesForAddress(ipv6Address)); } else { output.writeZero(Ipv6Util.IPV6_LENGTH); } } /** * Writes IPv6 prefix if not null, otherwise writes zeros to the * <code>output</code> ByteBuf. ByteBuf's writerIndex is increased by 17. * * @param ipv6Prefix * IPv6 prefix to be written to the output. Prefix is written in * the last byte. * @param output * ByteBuf, where ipv6Prefix or zeros are written. */ public static void writeIpv6Prefix(final Ipv6Prefix ipv6Prefix, final ByteBuf output) { if (ipv6Prefix != null) { output.writeBytes(Ipv6Util.bytesForPrefix(ipv6Prefix)); } else { output.writeZero(IPV6_PREFIX_BYTE_LENGTH); } } public static void writeMinimalPrefix(final Ipv4Prefix ipv4Prefix, final ByteBuf output) { final byte[] bytes = IetfInetUtil.INSTANCE.ipv4PrefixToBytes(ipv4Prefix); writeMinimalPrefix(output, bytes, bytes[Ipv4Util.IP4_LENGTH]); } public static void writeMinimalPrefix(final Ipv6Prefix ipv6Prefix, final ByteBuf output) { final byte[] bytes = IetfInetUtil.INSTANCE.ipv6PrefixToBytes(ipv6Prefix); writeMinimalPrefix(output, bytes, bytes[Ipv6Util.IPV6_LENGTH]); } private static void writeMinimalPrefix(final ByteBuf output, final byte[] bytes, final byte prefixBits) { output.writeByte(prefixBits); output.writeBytes(bytes, 0, Ipv4Util.prefixBitsToBytes(Byte.toUnsignedInt(prefixBits))); } /** * Writes Float32 <code>value</code> if not null, otherwise writes zeros to * the <code>output</code> ByteBuf. ByteBuf's writerIndex is increased by 4. * * @param value * Float32 value to be written to the output. * @param output * ByteBuf, where value or zeros are written. */ public static void writeFloat32(final Float32 value, final ByteBuf output) { if (value != null) { output.writeBytes(value.getValue()); } else { output.writeZero(FLOAT32_BYTES_LENGTH); } } /** * Writes BitSet's bits if not null, otherwise writes zeros to the * <code>output</code> ByteBuf. ByteBuf's writerIndex is increased by * specified length. * * @param bitSet * BitSet values to be written to the output, starting from left most bit. * @param outputLength * Number of bytes to be written, must be greater than 0. * @param output * ByteBuf, where bitSet or zeros are written. */ public static void writeBitSet(final BitSet bitSet, final int outputLength, final ByteBuf output) { Preconditions.checkArgument(outputLength > 0); if (bitSet != null) { output.writeBytes(ByteArray.bitSetToBytes(bitSet, outputLength)); } else { output.writeZero(outputLength); } } }