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. */ /** * This file is based on source code from the Hadoop Project (http://hadoop.apache.org/), licensed by the Apache * Software Foundation (ASF) under the Apache License, Version 2.0. See the NOTICE file distributed with this work for * additional information regarding copyright ownership. */ package org.apache.flink.runtime.net; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.InetAddress; import java.net.InetSocketAddress; import java.net.Socket; import java.net.SocketAddress; import java.net.URI; import java.net.URISyntaxException; import java.net.UnknownHostException; import java.nio.channels.SocketChannel; import java.util.ArrayList; import java.util.Collection; import java.util.HashMap; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import javax.net.SocketFactory; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.flink.runtime.ipc.Server; public class NetUtils { private static final Log LOG = LogFactory.getLog(NetUtils.class); private static Map<String, String> hostToResolved = new HashMap<String, String>(); public static SocketFactory getSocketFactory() { return getDefaultSocketFactory(); } public static SocketFactory getDefaultSocketFactory() { return SocketFactory.getDefault(); } /** * Util method to build socket addr from either: * <host>:<post> * <fs>://<host>:<port>/<path> */ public static InetSocketAddress createSocketAddr(String target) { return createSocketAddr(target, -1); } /** * Util method to build socket addr from either: * <host> * <host>:<post> * <fs>://<host>:<port>/<path> */ public static InetSocketAddress createSocketAddr(String target, int defaultPort) { int colonIndex = target.indexOf(':'); if (colonIndex < 0 && defaultPort == -1) { throw new RuntimeException("Not a host:port pair: " + target); } String hostname = ""; int port = -1; if (!target.contains("/")) { if (colonIndex == -1) { hostname = target; } else { // must be the old style <host>:<port> hostname = target.substring(0, colonIndex); port = Integer.parseInt(target.substring(colonIndex + 1)); } } else { // a new uri try { URI addr = new URI(target); hostname = addr.getHost(); port = addr.getPort(); } catch (URISyntaxException use) { LOG.fatal(use); } } if (port == -1) { port = defaultPort; } if (getStaticResolution(hostname) != null) { hostname = getStaticResolution(hostname); } return new InetSocketAddress(hostname, port); } /** * Adds a static resolution for host. This can be used for setting up * hostnames with names that are fake to point to a well known host. For e.g. * in some testcases we require to have daemons with different hostnames * running on the same machine. In order to create connections to these * daemons, one can set up mappings from those hostnames to "localhost". * {@link NetUtils#getStaticResolution(String)} can be used to query for * the actual hostname. * * @param host * @param resolvedName */ public static void addStaticResolution(String host, String resolvedName) { synchronized (hostToResolved) { hostToResolved.put(host, resolvedName); } } /** * Retrieves the resolved name for the passed host. The resolved name must * have been set earlier using {@link NetUtils#addStaticResolution(String, String)} * * @param host * @return the resolution */ public static String getStaticResolution(String host) { synchronized (hostToResolved) { return hostToResolved.get(host); } } /** * This is used to get all the resolutions that were added using * {@link NetUtils#addStaticResolution(String, String)}. The return * value is a List each element of which contains an array of String * of the form String[0]=hostname, String[1]=resolved-hostname * * @return the list of resolutions */ public static List<String[]> getAllStaticResolutions() { synchronized (hostToResolved) { Set<Entry<String, String>> entries = hostToResolved.entrySet(); if (entries.size() == 0) { return null; } List<String[]> l = new ArrayList<String[]>(entries.size()); for (Entry<String, String> e : entries) { l.add(new String[] { e.getKey(), e.getValue() }); } return l; } } /** * Returns InetSocketAddress that a client can use to * connect to the server. Server.getListenerAddress() is not correct when * the server binds to "0.0.0.0". This returns "127.0.0.1:port" when * the getListenerAddress() returns "0.0.0.0:port". * * @param server * @return socket address that a client can use to connect to the server. */ public static InetSocketAddress getConnectAddress(Server server) { InetSocketAddress addr = server.getListenerAddress(); if (addr.getAddress().getHostAddress().equals("0.0.0.0")) { addr = new InetSocketAddress("127.0.0.1", addr.getPort()); } return addr; } /** * Same as getInputStream(socket, socket.getSoTimeout()).<br> * <br> * From documentation for {@link #getInputStream(Socket, long)}:<br> * Returns InputStream for the socket. If the socket has an associated * SocketChannel then it returns a {@link SocketInputStream} with the given timeout. If the socket does not * have a channel, {@link Socket#getInputStream()} is returned. In the later * case, the timeout argument is ignored and the timeout set with {@link Socket#setSoTimeout(int)} applies for * reads.<br> * <br> * Any socket created using socket factories returned by {@link #NetUtils}, * must use this interface instead of {@link Socket#getInputStream()}. * * @see #getInputStream(Socket, long) * @param socket * @return InputStream for reading from the socket. * @throws IOException */ public static InputStream getInputStream(Socket socket) throws IOException { return getInputStream(socket, socket.getSoTimeout()); } /** * Returns InputStream for the socket. If the socket has an associated * SocketChannel then it returns a {@link SocketInputStream} with the given timeout. If the socket does not * have a channel, {@link Socket#getInputStream()} is returned. In the later * case, the timeout argument is ignored and the timeout set with {@link Socket#setSoTimeout(int)} applies for * reads.<br> * <br> * Any socket created using socket factories returned by {@link #NetUtils}, * must use this interface instead of {@link Socket#getInputStream()}. * * @see Socket#getChannel() * @param socket * @param timeout * timeout in milliseconds. This may not always apply. zero * for waiting as long as necessary. * @return InputStream for reading from the socket. * @throws IOException */ @SuppressWarnings("resource") public static InputStream getInputStream(Socket socket, long timeout) throws IOException { return (socket.getChannel() == null) ? socket.getInputStream() : new SocketInputStream(socket, timeout); } /** * Same as getOutputStream(socket, 0). Timeout of zero implies write will * wait until data is available.<br> * <br> * From documentation for {@link #getOutputStream(Socket, long)} : <br> * Returns OutputStream for the socket. If the socket has an associated * SocketChannel then it returns a {@link SocketOutputStream} with the given timeout. If the socket does not * have a channel, {@link Socket#getOutputStream()} is returned. In the later * case, the timeout argument is ignored and the write will wait until * data is available.<br> * <br> * Any socket created using socket factories returned by {@link #NetUtils}, * must use this interface instead of {@link Socket#getOutputStream()}. * * @see #getOutputStream(Socket, long) * @param socket * @return OutputStream for writing to the socket. * @throws IOException */ public static OutputStream getOutputStream(Socket socket) throws IOException { return getOutputStream(socket, 0); } /** * Returns OutputStream for the socket. If the socket has an associated * SocketChannel then it returns a {@link SocketOutputStream} with the given timeout. If the socket does not * have a channel, {@link Socket#getOutputStream()} is returned. In the later * case, the timeout argument is ignored and the write will wait until * data is available.<br> * <br> * Any socket created using socket factories returned by {@link #NetUtils}, * must use this interface instead of {@link Socket#getOutputStream()}. * * @see Socket#getChannel() * @param socket * @param timeout * timeout in milliseconds. This may not always apply. zero * for waiting as long as necessary. * @return OutputStream for writing to the socket. * @throws IOException */ @SuppressWarnings("resource") public static OutputStream getOutputStream(Socket socket, long timeout) throws IOException { return (socket.getChannel() == null) ? socket.getOutputStream() : new SocketOutputStream(socket, timeout); } public static void connect(Socket socket, SocketAddress endpoint, int timeout) throws IOException { if (socket == null || endpoint == null || timeout < 0) { throw new IllegalArgumentException("Illegal argument for connect()"); } SocketChannel ch = socket.getChannel(); if (ch == null) { // let the default implementation handle it. socket.connect(endpoint, timeout); } else { SocketIOWithTimeout.connect(ch, endpoint, timeout); } } /** * Given a string representation of a host, return its ip address * in textual presentation. * * @param name * a string representation of a host: * either a textual representation its IP address or its host name * @return its IP address in the string format */ public static String normalizeHostName(String name) { if (Character.digit(name.charAt(0), 16) != -1) { // it is an IP return name; } else { try { InetAddress ipAddress = InetAddress.getByName(name); return ipAddress.getHostAddress(); } catch (UnknownHostException e) { return name; } } } /** * Given a collection of string representation of hosts, return a list of * corresponding IP addresses in the textual representation. * * @param names * a collection of string representations of hosts * @return a list of corresponding IP addresses in the string format * @see #normalizeHostName(String) */ public static List<String> normalizeHostNames(Collection<String> names) { List<String> hostNames = new ArrayList<String>(names.size()); for (String name : names) { hostNames.add(normalizeHostName(name)); } return hostNames; } }