Java tutorial
/* * Copyright 2011 Edmunds.com, Inc. * * 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. */ package com.edmunds.etm.management.api; import com.edmunds.etm.common.thrift.HostAddressDto; import org.apache.commons.lang.StringUtils; import org.apache.commons.lang.Validate; import java.io.Serializable; import java.net.InetAddress; import java.net.UnknownHostException; import java.util.Properties; /** * Container for a host and address. <p/> The host may be a host name or a dotted quad (a.b.c.d) ip address. */ public class HostAddress implements Comparable<HostAddress>, Serializable { private final String host; private final int port; private String ipAddress; private String hostName; /** * Initializes the HostAddress object using a Properties object (loaded from the ZooKeeper node). * * @param properties the properties to use to initialize the object. */ public HostAddress(Properties properties) { this(properties.getProperty("address"), extractPort(properties)); } /** * Constructor. * * @param host the host name or ip address. * @param port the port number. */ public HostAddress(String host, int port) { Validate.notEmpty(host, "host cannot be empty"); this.host = host; this.port = port; } /** * Gets the host as originally defined. This may be a host name or an ip address. * * @return host name or ip address */ public String getHost() { return host; } /** * Gets the port number. * * @return port number */ public int getPort() { return port; } /** * Gets the host ip address. * * @return host ip address */ public String getIpAddress() { if (ipAddress == null) { try { InetAddress addr = InetAddress.getByName(host); ipAddress = addr.getHostAddress(); } catch (UnknownHostException e) { ipAddress = null; } } return ipAddress; } /** * Gets the host name. * * @return host name */ public String getHostName() { if (hostName == null) { try { InetAddress addr = InetAddress.getByName(host); hostName = addr.getHostName(); } catch (UnknownHostException e) { hostName = null; } } return hostName; } @Override public boolean equals(Object o) { if (this == o) { return true; } if (o == null || getClass() != o.getClass()) { return false; } HostAddress that = (HostAddress) o; return host.equals(that.host) && port == that.port; } @Override public int hashCode() { int result = host.hashCode(); result = 31 * result + port; return result; } @Override public String toString() { return host + ':' + port; } @Override public int compareTo(HostAddress other) { if (other == null) { return 1; } // Host cannot be null (see constructor). if (host.equals(other.host)) { return port - other.port; } return host.compareTo(other.host); } /** * Creates a HostAddress from the given DTO. * * @param dto the DTO to read * @return a HostAddress object */ public static HostAddress readDto(HostAddressDto dto) { if (dto == null) { return null; } return new HostAddress(dto.getHost(), dto.getPort()); } /** * Creates a DTO from the given HostAddress. * * @param value a HostAddress object * @return a data transfer object */ public static HostAddressDto writeDto(HostAddress value) { if (value == null) { return null; } return new HostAddressDto(value.host, value.port); } private static int extractPort(Properties properties) { final String portText = properties.getProperty("port"); Validate.notEmpty(portText, "port cannot be empty"); try { if (StringUtils.isNumeric(portText)) { return Integer.parseInt(portText); } else { throw new IllegalStateException("Port must be numeric: " + portText); } } catch (NumberFormatException e) { throw new IllegalStateException("Port must be numeric: " + portText, e); } } }