Java tutorial
/* * Copyright 2016 The Netty Project * * The Netty Project 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 io.netty.util.internal; import java.io.IOException; import java.net.InetAddress; import java.net.InetSocketAddress; import java.net.NetworkInterface; import java.net.ServerSocket; import java.net.Socket; import java.net.SocketAddress; import java.net.SocketException; import java.net.SocketPermission; import java.net.UnknownHostException; import java.nio.channels.DatagramChannel; import java.nio.channels.ServerSocketChannel; import java.nio.channels.SocketChannel; import java.security.AccessController; import java.security.PrivilegedAction; import java.security.PrivilegedActionException; import java.security.PrivilegedExceptionAction; import java.util.Enumeration; /** * Provides socket operations with privileges enabled. This is necessary for applications that use the * {@link SecurityManager} to restrict {@link SocketPermission} to their application. By asserting that these * operations are privileged, the operations can proceed even if some code in the calling chain lacks the appropriate * {@link SocketPermission}. */ public final class SocketUtils { private SocketUtils() { } public static void connect(final Socket socket, final SocketAddress remoteAddress, final int timeout) throws IOException { try { AccessController.doPrivileged(new PrivilegedExceptionAction<Void>() { @Override public Void run() throws IOException { socket.connect(remoteAddress, timeout); return null; } }); } catch (PrivilegedActionException e) { throw (IOException) e.getCause(); } } public static void bind(final Socket socket, final SocketAddress bindpoint) throws IOException { try { AccessController.doPrivileged(new PrivilegedExceptionAction<Void>() { @Override public Void run() throws IOException { socket.bind(bindpoint); return null; } }); } catch (PrivilegedActionException e) { throw (IOException) e.getCause(); } } public static boolean connect(final SocketChannel socketChannel, final SocketAddress remoteAddress) throws IOException { try { return AccessController.doPrivileged(new PrivilegedExceptionAction<Boolean>() { @Override public Boolean run() throws IOException { return socketChannel.connect(remoteAddress); } }); } catch (PrivilegedActionException e) { throw (IOException) e.getCause(); } } @SuppressJava6Requirement(reason = "Usage guarded by java version check") public static void bind(final SocketChannel socketChannel, final SocketAddress address) throws IOException { try { AccessController.doPrivileged(new PrivilegedExceptionAction<Void>() { @Override public Void run() throws IOException { socketChannel.bind(address); return null; } }); } catch (PrivilegedActionException e) { throw (IOException) e.getCause(); } } public static SocketChannel accept(final ServerSocketChannel serverSocketChannel) throws IOException { try { return AccessController.doPrivileged(new PrivilegedExceptionAction<SocketChannel>() { @Override public SocketChannel run() throws IOException { return serverSocketChannel.accept(); } }); } catch (PrivilegedActionException e) { throw (IOException) e.getCause(); } } @SuppressJava6Requirement(reason = "Usage guarded by java version check") public static void bind(final DatagramChannel networkChannel, final SocketAddress address) throws IOException { try { AccessController.doPrivileged(new PrivilegedExceptionAction<Void>() { @Override public Void run() throws IOException { networkChannel.bind(address); return null; } }); } catch (PrivilegedActionException e) { throw (IOException) e.getCause(); } } public static SocketAddress localSocketAddress(final ServerSocket socket) { return AccessController.doPrivileged(new PrivilegedAction<SocketAddress>() { @Override public SocketAddress run() { return socket.getLocalSocketAddress(); } }); } public static InetAddress addressByName(final String hostname) throws UnknownHostException { try { return AccessController.doPrivileged(new PrivilegedExceptionAction<InetAddress>() { @Override public InetAddress run() throws UnknownHostException { return InetAddress.getByName(hostname); } }); } catch (PrivilegedActionException e) { throw (UnknownHostException) e.getCause(); } } public static InetAddress[] allAddressesByName(final String hostname) throws UnknownHostException { try { return AccessController.doPrivileged(new PrivilegedExceptionAction<InetAddress[]>() { @Override public InetAddress[] run() throws UnknownHostException { return InetAddress.getAllByName(hostname); } }); } catch (PrivilegedActionException e) { throw (UnknownHostException) e.getCause(); } } public static InetSocketAddress socketAddress(final String hostname, final int port) { return AccessController.doPrivileged(new PrivilegedAction<InetSocketAddress>() { @Override public InetSocketAddress run() { return new InetSocketAddress(hostname, port); } }); } public static Enumeration<InetAddress> addressesFromNetworkInterface(final NetworkInterface intf) { return AccessController.doPrivileged(new PrivilegedAction<Enumeration<InetAddress>>() { @Override public Enumeration<InetAddress> run() { return intf.getInetAddresses(); } }); } @SuppressJava6Requirement(reason = "Usage guarded by java version check") public static InetAddress loopbackAddress() { return AccessController.doPrivileged(new PrivilegedAction<InetAddress>() { @Override public InetAddress run() { if (PlatformDependent.javaVersion() >= 7) { return InetAddress.getLoopbackAddress(); } try { return InetAddress.getByName(null); } catch (UnknownHostException e) { throw new IllegalStateException(e); } } }); } public static byte[] hardwareAddressFromNetworkInterface(final NetworkInterface intf) throws SocketException { try { return AccessController.doPrivileged(new PrivilegedExceptionAction<byte[]>() { @Override public byte[] run() throws SocketException { return intf.getHardwareAddress(); } }); } catch (PrivilegedActionException e) { throw (SocketException) e.getCause(); } } }