Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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. * */ package org.apache.directory.server.dhcp.messages; import com.google.common.base.CharMatcher; import com.google.common.base.Splitter; import com.google.common.collect.Iterables; import edu.umd.cs.findbugs.annotations.SuppressFBWarnings; import java.beans.PropertyEditorSupport; import javax.annotation.Nonnull; /** * A representation of a DHCP hardware address. * * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> */ public final class HardwareAddress { public static class PropertyEditor extends PropertyEditorSupport { @Override public String getJavaInitializationString() { String text = getAsText(); if (text == null) return "null"; else return "HardwareAddress.fromString(\"" + text + "\")"; } @Override public void setAsText(String text) { if (text == null) setValue(null); else setValue(HardwareAddress.fromString(text)); } } /** * [htype] Hardware address type, see ARP section in "Assigned Numbers" RFC; * e.g., '1' = 10mb ethernet. */ private final short type; /** * [hlen] Hardware address length (e.g. '6' for 10mb ethernet). */ private final short length; /** * [chaddr] Client hardware address. */ private final byte[] address; /** * @param type * @param length * @param address */ @SuppressFBWarnings("EI_EXPOSE_REP2") public HardwareAddress(short type, short length, @Nonnull byte[] address) { this.type = type; this.length = length; this.address = address; } public HardwareAddress(@Nonnull HardwareAddressType type, short length, @Nonnull byte[] address) { this(type.getCode(), length, address); } public HardwareAddress(@Nonnull HardwareAddressType type, @Nonnull byte[] address) { this(type.getCode(), (short) address.length, address); } @Nonnull @SuppressFBWarnings("EI_EXPOSE_REP") public byte[] getAddress() { return address; } public short getType() { return type; } public short getLength() { return length; } /** * @see java.lang.Object#hashCode() * @return the instance's hash code */ @Override public int hashCode() { int hashCode = 98643532 ^ type ^ length; for (int i = 0; i < length; i++) { hashCode ^= address[i]; } return hashCode; } /* * @see java.lang.Object#equals(java.lang.Object) */ @Override public boolean equals(Object obj) { if (this == obj) return true; if (null == obj) return false; if (!getClass().equals(obj.getClass())) return false; HardwareAddress hw = (HardwareAddress) obj; if (type != hw.type) return false; if (length != hw.length) return false; for (int i = 0; i < length; i++) if (address[i] != hw.address[i]) return false; return true; } /** * Create the string representation of the hardware address native to the * corresponding address type. This method currently supports only type * 1==ethernet with the representation <code>a1:a2:a3:a4:a5:a6</code>.<br> * For all other types, this method falls back to the representation created * by toString(). * * @see java.lang.Object#toString() */ @Nonnull public String getNativeRepresentation() { StringBuilder sb = new StringBuilder(); switch (type) { case 1: for (int i = 0; i < length; i++) { if (i > 0) { sb.append(":"); } String hex = Integer.toHexString(address[i] & 0xff); if (hex.length() < 2) { sb.append('0'); } sb.append(hex); } break; default: sb.append(toString()); } return sb.toString(); } /** * Create a string representation of the hardware address. The string * representation is in the format<br> * <code>t/a1:a2:a3...</code><br> * Where <code>t</code> represents the address type (decimal) and * <code>a<sub>n</sub></code> represent the address bytes (hexadecimal). * * @see java.lang.Object#toString() */ @Override public String toString() { StringBuilder sb = new StringBuilder(); sb.append(type); sb.append("/"); for (int i = 0; i < length; i++) { if (i > 0) { sb.append(":"); } String hex = Integer.toHexString(address[i] & 0xff); if (hex.length() < 2) { sb.append('0'); } sb.append(hex); } return sb.toString(); } /** * Parses a string representation of a hardware address. * Valid: 1/11:22:33:44:55:66 (toString()) * Valid: Ethernet/11:22:33:44:55:66 * Valid: 11:22:33:44:55:66 (defaults to Ethernet) * * @param text * @return HardwareAddress */ @Nonnull public static HardwareAddress fromString(@Nonnull String text) { int idx = text.indexOf('/'); HardwareAddressType hardwareAddressType = HardwareAddressType.Ethernet; if (idx != -1) { String hardwareAddressTypeText = text.substring(0, idx); try { int hardwareAddressTypeCode = Integer.parseInt(hardwareAddressTypeText); hardwareAddressType = HardwareAddressType.forCode(hardwareAddressTypeCode); } catch (NumberFormatException e) { // This will throw IllegalArgumentException, which is roughly what we want. hardwareAddressType = HardwareAddressType.valueOf(hardwareAddressTypeText); } text = text.substring(idx + 1); } CharMatcher separator = CharMatcher.BREAKING_WHITESPACE.or(CharMatcher.anyOf(":-")); Iterable<String> parts = Splitter.on(separator).omitEmptyStrings().trimResults().split(text); int i = 0; byte[] out = new byte[Iterables.size(parts)]; for (String part : parts) out[i++] = (byte) Integer.parseInt(part, 16); return new HardwareAddress(hardwareAddressType.getCode(), (short) out.length, out); } }