1 /* 2 * Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /* Test utilities 25 * 26 */ 27 28 import java.io.*; 29 import java.net.*; 30 import java.nio.channels.*; 31 import java.util.Random; 32 33 34 public class TestUtil { 35 36 // Test hosts used by the channels tests - change these when 37 // executing in a different network. 38 public static final String UNRESOLVABLE_HOST = "blah-blah.blah-blah.blah"; 39 40 private TestUtil() { } 41 42 // Repeatedly try random ports until we bind to one. You might be tempted 43 // to do this: 44 // 45 // ServerSocketChannel ssc = ServerSocketChannel.open(); 46 // ssc.socket().bind(new InetSocketAddress(0)); 47 // SocketAddress sa = ssc.socket().getLocalSocketAddress(); 48 // 49 // but unfortunately it doesn't work on NT 4.0. 50 // 51 // Returns the bound port. 52 // 53 static int bind(ServerSocketChannel ssc) throws IOException { 54 InetAddress lh = InetAddress.getLocalHost(); 55 Random r = new Random(); 56 for (;;) { 57 int p = r.nextInt((1 << 16) - 1024) + 1024; 58 InetSocketAddress isa = new InetSocketAddress(lh, p); 59 try { 60 ssc.socket().bind(isa); 61 } catch (IOException x) { 62 continue; 63 } 64 return p; 65 } 66 } 67 68 // A more convenient form of bind(ServerSocketChannel) that returns a full 69 // socket address. 70 // 71 static InetSocketAddress bindToRandomPort(ServerSocketChannel ssc) 72 throws IOException 73 { 74 int p = bind(ssc); 75 return new InetSocketAddress(InetAddress.getLocalHost(), p); 76 } 77 78 private static String osName = System.getProperty("os.name"); 79 80 static boolean onWindows() { 81 return osName.startsWith("Windows"); 82 } 83 }