hadoop NetUtils 源码

  • 2022-10-20
  • 浏览 (191)

haddop NetUtils 代码

文件路径:/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/net/NetUtils.java

/**
 * 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.hadoop.net;

import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Constructor;
import java.net.BindException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.NetworkInterface;
import java.net.NoRouteToHostException;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketAddress;
import java.net.SocketException;
import java.net.SocketTimeoutException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.UnknownHostException;
import java.net.ConnectException;
import java.nio.channels.SocketChannel;
import java.nio.channels.UnresolvedAddressException;
import java.util.Map.Entry;
import java.util.concurrent.TimeUnit;
import java.util.regex.Pattern;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;

import javax.net.SocketFactory;

import org.apache.hadoop.security.AccessControlException;
import org.apache.hadoop.thirdparty.com.google.common.cache.Cache;
import org.apache.hadoop.thirdparty.com.google.common.cache.CacheBuilder;

import org.apache.commons.net.util.SubnetUtils;
import org.apache.commons.net.util.SubnetUtils.SubnetInfo;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
import org.apache.hadoop.ipc.Server;
import org.apache.hadoop.ipc.VersionedProtocol;
import org.apache.hadoop.security.SecurityUtil;
import org.apache.hadoop.util.ReflectionUtils;
import org.apache.hadoop.util.Preconditions;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@InterfaceAudience.LimitedPrivate({"HDFS", "MapReduce"})
@InterfaceStability.Unstable
public class NetUtils {
  private static final Logger LOG = LoggerFactory.getLogger(NetUtils.class);
  
  private static Map<String, String> hostToResolved = 
                                     new HashMap<String, String>();
  /** text to point users elsewhere: {@value} */
  private static final String FOR_MORE_DETAILS_SEE
      = " For more details see:  ";
  /** text included in wrapped exceptions if the host is null: {@value} */
  public static final String UNKNOWN_HOST = "(unknown)";
  /** Base URL of the Hadoop Wiki: {@value} */
  public static final String HADOOP_WIKI = "http://wiki.apache.org/hadoop/";

  /**
   * Get the socket factory for the given class according to its
   * configuration parameter
   * <tt>hadoop.rpc.socket.factory.class.&lt;ClassName&gt;</tt>. When no
   * such parameter exists then fall back on the default socket factory as
   * configured by <tt>hadoop.rpc.socket.factory.class.default</tt>. If
   * this default socket factory is not configured, then fall back on the JVM
   * default socket factory.
   * 
   * @param conf the configuration
   * @param clazz the class (usually a {@link VersionedProtocol})
   * @return a socket factory
   */
  public static SocketFactory getSocketFactory(Configuration conf,
      Class<?> clazz) {

    SocketFactory factory = null;

    String propValue =
        conf.get("hadoop.rpc.socket.factory.class." + clazz.getSimpleName());
    if ((propValue != null) && (propValue.length() > 0))
      factory = getSocketFactoryFromProperty(conf, propValue);

    if (factory == null)
      factory = getDefaultSocketFactory(conf);

    return factory;
  }

  /**
   * Get the default socket factory as specified by the configuration
   * parameter <tt>hadoop.rpc.socket.factory.default</tt>
   * 
   * @param conf the configuration
   * @return the default socket factory as specified in the configuration or
   *         the JVM default socket factory if the configuration does not
   *         contain a default socket factory property.
   */
  public static SocketFactory getDefaultSocketFactory(Configuration conf) {

    String propValue = conf.get(
        CommonConfigurationKeysPublic.HADOOP_RPC_SOCKET_FACTORY_CLASS_DEFAULT_KEY,
        CommonConfigurationKeysPublic.HADOOP_RPC_SOCKET_FACTORY_CLASS_DEFAULT_DEFAULT);
    if ((propValue == null) || (propValue.length() == 0))
      return SocketFactory.getDefault();

    return getSocketFactoryFromProperty(conf, propValue);
  }

  /**
   * Get the socket factory corresponding to the given proxy URI. If the
   * given proxy URI corresponds to an absence of configuration parameter,
   * returns null. If the URI is malformed raises an exception.
   *
   * @param conf configuration.
   * @param propValue the property which is the class name of the
   *        SocketFactory to instantiate; assumed non null and non empty.
   * @return a socket factory as defined in the property value.
   */
  public static SocketFactory getSocketFactoryFromProperty(
      Configuration conf, String propValue) {

    try {
      Class<?> theClass = conf.getClassByName(propValue);
      return (SocketFactory) ReflectionUtils.newInstance(theClass, conf);

    } catch (ClassNotFoundException cnfe) {
      throw new RuntimeException("Socket Factory class not found: " + cnfe);
    }
  }

  /**
   * Util method to build socket addr from either.
   *   {@literal <host>:<port>}
   *   {@literal <fs>://<host>:<port>/<path>}
   *
   * @param target target.
   * @return socket addr.
   */
  public static InetSocketAddress createSocketAddr(String target) {
    return createSocketAddr(target, -1);
  }

  /**
   * Util method to build socket addr from either.
   *   {@literal <host>}
   *   {@literal <host>:<port>}
   *   {@literal <fs>://<host>:<port>/<path>}
   *
   * @param target target.
   * @param defaultPort default port.
   * @return socket addr.
   */
  public static InetSocketAddress createSocketAddr(String target,
                                                   int defaultPort) {
    return createSocketAddr(target, defaultPort, null);
  }

  /**
   * Create an InetSocketAddress from the given target string and
   * default port. If the string cannot be parsed correctly, the
   * <code>configName</code> parameter is used as part of the
   * exception message, allowing the user to better diagnose
   * the misconfiguration.
   *
   * @param target a string of either "host" or "host:port"
   * @param defaultPort the default port if <code>target</code> does not
   *                    include a port number
   * @param configName the name of the configuration from which
   *                   <code>target</code> was loaded. This is used in the
   *                   exception message in the case that parsing fails.
   * @return socket addr.
   */
  public static InetSocketAddress createSocketAddr(String target,
                                                   int defaultPort,
                                                   String configName) {
    return createSocketAddr(target, defaultPort, configName, false);
  }

  /**
   * Create an InetSocketAddress from the given target string and
   * default port. If the string cannot be parsed correctly, the
   * <code>configName</code> parameter is used as part of the
   * exception message, allowing the user to better diagnose
   * the misconfiguration.
   *
   * @param target a string of either "host" or "host:port"
   * @param defaultPort the default port if <code>target</code> does not
   *                    include a port number
   * @param configName the name of the configuration from which
   *                   <code>target</code> was loaded. This is used in the
   *                   exception message in the case that parsing fails.
   * @param useCacheIfPresent Whether use cache when create URI
   * @return  socket addr
   */
  public static InetSocketAddress createSocketAddr(String target,
                                                   int defaultPort,
                                                   String configName,
                                                   boolean useCacheIfPresent) {
    String helpText = "";
    if (configName != null) {
      helpText = " (configuration property '" + configName + "')";
    }
    if (target == null) {
      throw new IllegalArgumentException("Target address cannot be null." +
          helpText);
    }
    target = target.trim();
    boolean hasScheme = target.contains("://");
    URI uri = createURI(target, hasScheme, helpText, useCacheIfPresent);

    String host = uri.getHost();
    int port = uri.getPort();
    if (port == -1) {
      port = defaultPort;
    }
    String path = uri.getPath();

    if ((host == null) || (port < 0) ||
        (!hasScheme && path != null && !path.isEmpty())) {
      throw new IllegalArgumentException(
          "Does not contain a valid host:port authority: " + target + helpText
      );
    }
    return createSocketAddrForHost(host, port);
  }

  private static final long URI_CACHE_SIZE_DEFAULT = 1000;
  private static final long URI_CACHE_EXPIRE_TIME_DEFAULT = 12;
  private static final Cache<String, URI> URI_CACHE = CacheBuilder.newBuilder()
      .maximumSize(URI_CACHE_SIZE_DEFAULT)
      .expireAfterWrite(URI_CACHE_EXPIRE_TIME_DEFAULT, TimeUnit.HOURS)
      .build();

  private static URI createURI(String target,
                               boolean hasScheme,
                               String helpText,
                               boolean useCacheIfPresent) {
    URI uri;
    if (useCacheIfPresent) {
      uri = URI_CACHE.getIfPresent(target);
      if (uri != null) {
        return uri;
      }
    }

    try {
      uri = hasScheme ? URI.create(target) :
              URI.create("dummyscheme://" + target);
    } catch (IllegalArgumentException e) {
      throw new IllegalArgumentException(
          "Does not contain a valid host:port authority: " + target + helpText
      );
    }

    if (useCacheIfPresent) {
      URI_CACHE.put(target, uri);
    }
    return uri;
  }

  /**
   * Create a socket address with the given host and port.  The hostname
   * might be replaced with another host that was set via
   * {@link #addStaticResolution(String, String)}.  The value of
   * hadoop.security.token.service.use_ip will determine whether the
   * standard java host resolver is used, or if the fully qualified resolver
   * is used.
   * @param host the hostname or IP use to instantiate the object
   * @param port the port number
   * @return InetSocketAddress
   */
  public static InetSocketAddress createSocketAddrForHost(String host, int port) {
    String staticHost = getStaticResolution(host);
    String resolveHost = (staticHost != null) ? staticHost : host;
    
    InetSocketAddress addr;
    try {
      InetAddress iaddr = SecurityUtil.getByName(resolveHost);
      // if there is a static entry for the host, make the returned
      // address look like the original given host
      if (staticHost != null) {
        iaddr = InetAddress.getByAddress(host, iaddr.getAddress());
      }
      addr = new InetSocketAddress(iaddr, port);
    } catch (UnknownHostException e) {
      addr = InetSocketAddress.createUnresolved(host, port);
    }
    return addr;
  }
  
  /**
   * Resolve the uri's hostname and add the default port if not in the uri
   * @param uri to resolve
   * @param defaultPort if none is given
   * @return URI
   */
  public static URI getCanonicalUri(URI uri, int defaultPort) {
    // skip if there is no authority, ie. "file" scheme or relative uri
    String host = uri.getHost();
    if (host == null) {
      return uri;
    }
    String fqHost = canonicalizeHost(host);
    int port = uri.getPort();
    // short out if already canonical with a port
    if (host.equals(fqHost) && port != -1) {
      return uri;
    }
    // reconstruct the uri with the canonical host and port
    try {
      uri = new URI(uri.getScheme(), uri.getUserInfo(),
          fqHost, (port == -1) ? defaultPort : port,
          uri.getPath(), uri.getQuery(), uri.getFragment());
    } catch (URISyntaxException e) {
      throw new IllegalArgumentException(e);
    }
    return uri;
  }  

  // cache the canonicalized hostnames;  the cache currently isn't expired,
  // but the canonicals will only change if the host's resolver configuration
  // changes
  private static final ConcurrentHashMap<String, String> canonicalizedHostCache =
      new ConcurrentHashMap<String, String>();

  private static String canonicalizeHost(String host) {
    // check if the host has already been canonicalized
    String fqHost = canonicalizedHostCache.get(host);
    if (fqHost == null) {
      try {
        fqHost = SecurityUtil.getByName(host).getHostName();
        canonicalizedHostCache.putIfAbsent(host, fqHost);
        // ensures that we won't return a canonicalized stale (non-cached)
        // host name for a given host
        fqHost = canonicalizedHostCache.get(host);
      } catch (UnknownHostException e) {
        fqHost = host;
      }
    }
    return fqHost;
  }

  /**
   * 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 the hostname or IP use to instantiate the object.
   * @param resolvedName resolved name.
   */
  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 the hostname or IP use to instantiate the object.
   * @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 "hostname:port" of the server,
   * or "127.0.0.1:port" when the getListenerAddress() returns "0.0.0.0:port".
   * 
   * @param server server.
   * @return socket address that a client can use to connect to the server.
   */
  public static InetSocketAddress getConnectAddress(Server server) {
    return getConnectAddress(server.getListenerAddress());
  }
  
  /**
   * Returns an InetSocketAddress that a client can use to connect to the
   * given listening address.
   * 
   * @param addr of a listener
   * @return socket address that a client can use to connect to the server.
   */
  public static InetSocketAddress getConnectAddress(InetSocketAddress addr) {
    if (!addr.isUnresolved() && addr.getAddress().isAnyLocalAddress()) {
      try {
        addr = new InetSocketAddress(InetAddress.getLocalHost(), addr.getPort());
      } catch (UnknownHostException uhe) {
        // shouldn't get here unless the host doesn't have a loopback iface
        addr = createSocketAddrForHost("127.0.0.1", addr.getPort());
      }
    }
    return addr;
  }
  
  /**
   * Same as <code>getInputStream(socket, socket.getSoTimeout()).</code>
   *
   * @param socket socket.
   * @throws IOException raised on errors performing I/O.
   * @return SocketInputWrapper for reading from the socket.
   * @see #getInputStream(Socket, long)
   */
  public static SocketInputWrapper getInputStream(Socket socket) 
                                           throws IOException {
    return getInputStream(socket, socket.getSoTimeout());
  }

  /**
   * Return a {@link SocketInputWrapper} for the socket and set the given
   * timeout. If the socket does not have an associated channel, then its socket
   * timeout will be set to the specified value. Otherwise, a
   * {@link SocketInputStream} will be created which reads with the configured
   * timeout.
   * 
   * Any socket created using socket factories returned by {@link #NetUtils},
   * must use this interface instead of {@link Socket#getInputStream()}.
   * 
   * In general, this should be called only once on each socket: see the note
   * in {@link SocketInputWrapper#setTimeout(long)} for more information.
   *
   * @see Socket#getChannel()
   * 
   * @param socket socket.
   * @param timeout timeout in milliseconds. zero for waiting as
   *                long as necessary.
   * @return SocketInputWrapper for reading from the socket.
   * @throws IOException raised on errors performing I/O.
   */
  public static SocketInputWrapper getInputStream(Socket socket, long timeout) 
                                           throws IOException {
    InputStream stm = (socket.getChannel() == null) ? 
          socket.getInputStream() : new SocketInputStream(socket);
    SocketInputWrapper w = new SocketInputWrapper(socket, stm);
    w.setTimeout(timeout);
    return w;
  }
  
  /**
   * 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 socket.
   * @return OutputStream for writing to the socket.
   * @throws IOException raised on errors performing I/O.
   */  
  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 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 raised on errors performing I/O.
   */
  public static OutputStream getOutputStream(Socket socket, long timeout) 
                                             throws IOException {
    return (socket.getChannel() == null) ? 
            socket.getOutputStream() : new SocketOutputStream(socket, timeout);            
  }
  
  /**
   * This is a drop-in replacement for 
   * {@link Socket#connect(SocketAddress, int)}.
   * In the case of normal sockets that don't have associated channels, this 
   * just invokes <code>socket.connect(endpoint, timeout)</code>. If 
   * <code>socket.getChannel()</code> returns a non-null channel,
   * connect is implemented using Hadoop's selectors. This is done mainly
   * to avoid Sun's connect implementation from creating thread-local 
   * selectors, since Hadoop does not have control on when these are closed
   * and could end up taking all the available file descriptors.
   * 
   * @see java.net.Socket#connect(java.net.SocketAddress, int)
   * 
   * @param socket socket.
   * @param address the remote address
   * @param timeout timeout in milliseconds
   * @throws IOException raised on errors performing I/O.
   */
  public static void connect(Socket socket,
      SocketAddress address,
      int timeout) throws IOException {
    connect(socket, address, null, timeout);
  }

  /**
   * Like {@link NetUtils#connect(Socket, SocketAddress, int)} but
   * also takes a local address and port to bind the socket to. 
   * 
   * @param socket socket.
   * @param endpoint the remote address
   * @param localAddr the local address to bind the socket to
   * @param timeout timeout in milliseconds
   * @throws IOException raised on errors performing I/O.
   */
  public static void connect(Socket socket, 
                             SocketAddress endpoint,
                             SocketAddress localAddr,
                             int timeout) throws IOException {
    if (socket == null || endpoint == null || timeout < 0) {
      throw new IllegalArgumentException("Illegal argument for connect()");
    }
    
    SocketChannel ch = socket.getChannel();
    
    if (localAddr != null) {
      Class localClass = localAddr.getClass();
      Class remoteClass = endpoint.getClass();
      Preconditions.checkArgument(localClass.equals(remoteClass),
          "Local address %s must be of same family as remote address %s.",
          localAddr, endpoint);
      socket.bind(localAddr);
    }

    try {
      if (ch == null) {
        // let the default implementation handle it.
        socket.connect(endpoint, timeout);
      } else {
        SocketIOWithTimeout.connect(ch, endpoint, timeout);
      }
    } catch (SocketTimeoutException ste) {
      throw new ConnectTimeoutException(ste.getMessage());
    }  catch (UnresolvedAddressException uae) {
      throw new UnknownHostException(endpoint.toString());
    }

    // There is a very rare case allowed by the TCP specification, such that
    // if we are trying to connect to an endpoint on the local machine,
    // and we end up choosing an ephemeral port equal to the destination port,
    // we will actually end up getting connected to ourself (ie any data we
    // send just comes right back). This is only possible if the target
    // daemon is down, so we'll treat it like connection refused.
    if (socket.getLocalPort() == socket.getPort() &&
        socket.getLocalAddress().equals(socket.getInetAddress())) {
      LOG.info("Detected a loopback TCP socket, disconnecting it");
      socket.close();
      throw new ConnectException(
        "Localhost targeted connection resulted in a loopback. " +
        "No daemon is listening on the target port.");
    }
  }
  
  /** 
   * 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) {
    try {
      return InetAddress.getByName(name).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;
  }

  /**
   * Performs a sanity check on the list of hostnames/IPs to verify they at least
   * appear to be valid.
   * @param names - List of hostnames/IPs
   * @throws UnknownHostException Unknown Host Exception.
   */
  public static void verifyHostnames(String[] names) throws UnknownHostException {
    for (String name: names) {
      if (name == null) {
        throw new UnknownHostException("null hostname found");
      }
      // The first check supports URL formats (e.g. hdfs://, etc.). 
      // java.net.URI requires a schema, so we add a dummy one if it doesn't
      // have one already.
      URI uri = null;
      try {
        uri = new URI(name);
        if (uri.getHost() == null) {
          uri = new URI("http://" + name);
        }
      } catch (URISyntaxException e) {
        uri = null;
      }
      if (uri == null || uri.getHost() == null) {
        throw new UnknownHostException(name + " is not a valid Inet address");
      }
    }
  }

  private static final Pattern ipPortPattern = // Pattern for matching ip[:port]
    Pattern.compile("\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}(:\\d+)?");
  
  /**
   * Attempt to obtain the host name of the given string which contains
   * an IP address and an optional port.
   * 
   * @param ipPort string of form ip[:port]
   * @return Host name or null if the name can not be determined
   */
  public static String getHostNameOfIP(String ipPort) {
    if (null == ipPort || !ipPortPattern.matcher(ipPort).matches()) {
      return null;
    }
    
    try {
      int colonIdx = ipPort.indexOf(':');
      String ip = (-1 == colonIdx) ? ipPort
          : ipPort.substring(0, ipPort.indexOf(':'));
      return InetAddress.getByName(ip).getHostName();
    } catch (UnknownHostException e) {
      return null;
    }
  }

  /**
   * Attempt to normalize the given string to "host:port"
   * if it like "ip:port".
   *
   * @param ipPort maybe lik ip:port or host:port.
   * @return host:port
   */
  public static String normalizeIP2HostName(String ipPort) {
    if (null == ipPort || !ipPortPattern.matcher(ipPort).matches()) {
      return ipPort;
    }

    InetSocketAddress address = createSocketAddr(ipPort);
    return getHostPortString(address);
  }

  /**
   * Return hostname without throwing exception.
   * The returned hostname String format is "hostname".
   * @return hostname
   */
  public static String getLocalHostname() {
    try {
      return InetAddress.getLocalHost().getHostName();
    } catch(UnknownHostException uhe) {
      return "" + uhe;
    }
  }

  /**
   * Return hostname without throwing exception.
   * The returned hostname String format is "hostname/ip address".
   * @return hostname
   */
  public static String getHostname() {
    try {return "" + InetAddress.getLocalHost();}
    catch(UnknownHostException uhe) {return "" + uhe;}
  }

  /**
   * Compose a "host:port" string from the address.
   *
   * @param addr address.
   * @return hort port string.
   */
  public static String getHostPortString(InetSocketAddress addr) {
    return addr.getHostName() + ":" + addr.getPort();
  }

  /**
   * Get port as integer from host port string like host:port.
   *
   * @param addr host + port string like host:port.
   * @return an integer value representing the port.
   * @throws IllegalArgumentException if the input is not in the correct format.
   */
  public static int getPortFromHostPortString(String addr)
      throws IllegalArgumentException {
    String[] hostport = addr.split(":");
    if (hostport.length != 2) {
      String errorMsg = "Address should be <host>:<port>, but it is " + addr;
      throw new IllegalArgumentException(errorMsg);
    }
    return Integer.parseInt(hostport[1]);
  }
  
  /**
   * Checks if {@code host} is a local host name and return {@link InetAddress}
   * corresponding to that address.
   * 
   * @param host the specified host
   * @return a valid local {@link InetAddress} or null
   * @throws SocketException if an I/O error occurs
   */
  public static InetAddress getLocalInetAddress(String host)
      throws SocketException {
    if (host == null) {
      return null;
    }
    InetAddress addr = null;
    try {
      addr = SecurityUtil.getByName(host);
      if (NetworkInterface.getByInetAddress(addr) == null) {
        addr = null; // Not a local address
      }
    } catch (UnknownHostException ignore) { }
    return addr;
  }
  
  /**
   * Given an InetAddress, checks to see if the address is a local address, by
   * comparing the address with all the interfaces on the node.
   * @param addr address to check if it is local node's address
   * @return true if the address corresponds to the local node
   */
  public static boolean isLocalAddress(InetAddress addr) {
    // Check if the address is any local or loop back
    boolean local = addr.isAnyLocalAddress() || addr.isLoopbackAddress();

    // Check if the address is defined on any interface
    if (!local) {
      try {
        local = NetworkInterface.getByInetAddress(addr) != null;
      } catch (SocketException e) {
        local = false;
      }
    }
    return local;
  }

  /**
   * Take an IOException , the local host port and remote host port details and
   * return an IOException with the input exception as the cause and also
   * include the host details. The new exception provides the stack trace of the
   * place where the exception is thrown and some extra diagnostics information.
   * If the exception is of type BindException, ConnectException,
   * UnknownHostException, SocketTimeoutException or has a String constructor,
   * return a new one of the same type; Otherwise return an IOException.
   *
   * @param destHost target host (nullable)
   * @param destPort target port
   * @param localHost local host (nullable)
   * @param localPort local port
   * @param exception the caught exception.
   * @return an exception to throw
   */
  public static IOException wrapException(final String destHost,
                                          final int destPort,
                                          final String localHost,
                                          final int localPort,
                                          final IOException exception) {
    try {
      if (exception instanceof BindException) {
        return wrapWithMessage(exception,
            "Problem binding to ["
                + localHost
                + ":"
                + localPort
                + "] "
                + exception
                + ";"
                + see("BindException"));
      } else if (exception instanceof ConnectException) {
        // Check if client was trying to connect to an unspecified IPv4 address
        // (0.0.0.0) or IPv6 address(0:0:0:0:0:0:0:0 or ::)
        if ((destHost != null && (destHost.equals("0.0.0.0") ||
            destHost.equals("0:0:0:0:0:0:0:0") || destHost.equals("::")))
            || destPort == 0) {
          return wrapWithMessage(exception, "Your endpoint configuration" +
              " is wrong;" + see("UnsetHostnameOrPort"));
        } else {
          // connection refused; include the host:port in the error
          return wrapWithMessage(exception,
              "Call From "
                  + localHost
                  + " to "
                  + destHost
                  + ":"
                  + destPort
                  + " failed on connection exception: "
                  + exception
                  + ";"
                  + see("ConnectionRefused"));
        }
      } else if (exception instanceof UnknownHostException) {
        return wrapWithMessage(exception,
            "Invalid host name: "
                + getHostDetailsAsString(destHost, destPort, localHost)
                + exception
                + ";"
                + see("UnknownHost"));
      } else if (exception instanceof SocketTimeoutException) {
        return wrapWithMessage(exception,
            "Call From "
                + localHost + " to " + destHost + ":" + destPort
                + " failed on socket timeout exception: " + exception
                + ";"
                + see("SocketTimeout"));
      } else if (exception instanceof NoRouteToHostException) {
        return wrapWithMessage(exception,
            "No Route to Host from  "
                + localHost + " to " + destHost + ":" + destPort
                + " failed on socket timeout exception: " + exception
                + ";"
                + see("NoRouteToHost"));
      } else if (exception instanceof EOFException) {
        return wrapWithMessage(exception,
            "End of File Exception between "
                + getHostDetailsAsString(destHost, destPort, localHost)
                + ": " + exception
                + ";"
                + see("EOFException"));
      } else if (exception instanceof SocketException) {
        // Many of the predecessor exceptions are subclasses of SocketException,
        // so must be handled before this
        return wrapWithMessage(exception,
            "Call From "
                + localHost + " to " + destHost + ":" + destPort
                + " failed on socket exception: " + exception
                + ";"
                + see("SocketException"));
      } else if (exception instanceof AccessControlException) {
        return wrapWithMessage(exception,
            "Call From "
                + localHost + " to " + destHost + ":" + destPort
                + " failed: " + exception.getMessage());
      } else {
        // 1. Return instance of same type with exception msg if Exception has a
        // String constructor.
        // 2. Return instance of same type if Exception doesn't have a String
        // constructor.
        // Related HADOOP-16453.
        return wrapWithMessage(exception,
            "DestHost:destPort " + destHost + ":" + destPort
                + " , LocalHost:localPort " + localHost
                + ":" + localPort + ". Failed on local exception: " +
                exception);

      }
    } catch (IOException ex) {
      return (IOException) new IOException("Failed on local exception: "
          + exception + "; Host Details : "
          + getHostDetailsAsString(destHost, destPort, localHost))
          .initCause(exception);
    }
  }

  private static String see(final String entry) {
    return FOR_MORE_DETAILS_SEE + HADOOP_WIKI + entry;
  }
  
  @SuppressWarnings("unchecked")
  private static <T extends IOException> T wrapWithMessage(
      T exception, String msg) throws T {
    Class<? extends Throwable> clazz = exception.getClass();
    try {
      Constructor<? extends Throwable> ctor = clazz.getConstructor(String.class);
      Throwable t = ctor.newInstance(msg);
      return (T)(t.initCause(exception));
    } catch (NoSuchMethodException e) {
      return exception;
    } catch (Throwable e) {
      throw exception;
    }
  }

  /**
   * Get the host details as a string
   * @param destHost destinatioon host (nullable)
   * @param destPort destination port
   * @param localHost local host (nullable)
   * @return a string describing the destination host:port and the local host
   */
  private static String getHostDetailsAsString(final String destHost,
                                               final int destPort,
                                               final String localHost) {
    StringBuilder hostDetails = new StringBuilder(27);
    hostDetails.append("local host is: ")
        .append(quoteHost(localHost))
        .append("; ")
        .append("destination host is: ").append(quoteHost(destHost))
        .append(":")
        .append(destPort).append("; ");
    return hostDetails.toString();
  }

  /**
   * Quote a hostname if it is not null
   * @param hostname the hostname; nullable
   * @return a quoted hostname or {@link #UNKNOWN_HOST} if the hostname is null
   */
  private static String quoteHost(final String hostname) {
    return (hostname != null) ?
        ("\"" + hostname + "\"")
        : UNKNOWN_HOST;
  }

  /**
   * isValidSubnet.
   * @param subnet subnet.
   * @return true if the given string is a subnet specified
   *     using CIDR notation, false otherwise
   */
  public static boolean isValidSubnet(String subnet) {
    try {
      new SubnetUtils(subnet);
      return true;
    } catch (IllegalArgumentException iae) {
      return false;
    }
  }

  /**
   * Add all addresses associated with the given nif in the
   * given subnet to the given list.
   */
  private static void addMatchingAddrs(NetworkInterface nif,
      SubnetInfo subnetInfo, List<InetAddress> addrs) {
    Enumeration<InetAddress> ifAddrs = nif.getInetAddresses();
    while (ifAddrs.hasMoreElements()) {
      InetAddress ifAddr = ifAddrs.nextElement();
      if (subnetInfo.isInRange(ifAddr.getHostAddress())) {
        addrs.add(ifAddr);
      }
    }
  }

  /**
   * Return an InetAddress for each interface that matches the
   * given subnet specified using CIDR notation.
   *
   * @param subnet subnet specified using CIDR notation
   * @param returnSubinterfaces
   *            whether to return IPs associated with subinterfaces
   * @throws IllegalArgumentException if subnet is invalid
   * @return ips.
   */
  public static List<InetAddress> getIPs(String subnet,
      boolean returnSubinterfaces) {
    List<InetAddress> addrs = new ArrayList<InetAddress>();
    SubnetInfo subnetInfo = new SubnetUtils(subnet).getInfo();
    Enumeration<NetworkInterface> nifs;

    try {
      nifs = NetworkInterface.getNetworkInterfaces();
    } catch (SocketException e) {
      LOG.error("Unable to get host interfaces", e);
      return addrs;
    }

    while (nifs.hasMoreElements()) {
      NetworkInterface nif = nifs.nextElement();
      // NB: adding addresses even if the nif is not up
      addMatchingAddrs(nif, subnetInfo, addrs);

      if (!returnSubinterfaces) {
        continue;
      }
      Enumeration<NetworkInterface> subNifs = nif.getSubInterfaces();
      while (subNifs.hasMoreElements()) {
        addMatchingAddrs(subNifs.nextElement(), subnetInfo, addrs);
      }
    }
    return addrs;
  }

  /**
   * Return a free port number. There is no guarantee it will remain free, so
   * it should be used immediately.
   *
   * @return A free port for binding a local socket
   */
  public static int getFreeSocketPort() {
    int port = 0;
    try {
      ServerSocket s = new ServerSocket(0);
      port = s.getLocalPort();
      s.close();
      return port;
    } catch (IOException e) {
      // Could not get a free port. Return default port 0.
    }
    return port;
  }

  /**
   * Return free ports. There is no guarantee they will remain free, so
   * ports should be used immediately. The number of free ports returned by
   * this method should match argument {@code numOfPorts}. Num of ports
   * provided in the argument should not exceed 25.
   *
   * @param numOfPorts Number of free ports to acquire.
   * @return Free ports for binding a local socket.
   */
  public static Set<Integer> getFreeSocketPorts(int numOfPorts) {
    Preconditions.checkArgument(numOfPorts > 0 && numOfPorts <= 25,
        "Valid range for num of ports is between 0 and 26");
    final Set<Integer> freePorts = new HashSet<>(numOfPorts);
    for (int i = 0; i < numOfPorts * 5; i++) {
      int port = getFreeSocketPort();
      if (port == 0) {
        continue;
      }
      freePorts.add(port);
      if (freePorts.size() == numOfPorts) {
        return freePorts;
      }
    }
    throw new IllegalStateException(numOfPorts + " free ports could not be acquired.");
  }

  /**
   * Return an @{@link InetAddress} to bind to. If bindWildCardAddress is true
   * than returns null.
   *
   * @param localAddr local addr.
   * @param bindWildCardAddress bind wildcard address.
   * @return InetAddress
   */
  public static InetAddress bindToLocalAddress(InetAddress localAddr, boolean
      bindWildCardAddress) {
    if (!bindWildCardAddress) {
      return localAddr;
    }
    return null;
  }
}

相关信息

hadoop 源码目录

相关文章

hadoop AbstractDNSToSwitchMapping 源码

hadoop CachedDNSToSwitchMapping 源码

hadoop ConnectTimeoutException 源码

hadoop DNS 源码

hadoop DNSDomainNameResolver 源码

hadoop DNSToSwitchMapping 源码

hadoop DNSToSwitchMappingWithDependency 源码

hadoop DomainNameResolver 源码

hadoop DomainNameResolverFactory 源码

hadoop InnerNode 源码

0  赞