Java example source code file (StreamTimeout.java)

This example Java source code file (StreamTimeout.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

client, exception, expected, incorrect, interruptedioexception, ioexception, net, network, override, printstream, read, reader, second, serversocket, socket, string

The StreamTimeout.java Java example source code

/*
 * Copyright (c) 2010, 2012, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/* @test
 * @bug 4521942
 * @summary Ensure that InputStreamReaders work properly
 *          when the underlying byte stream times out
 */

import java.io.Closeable;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.InterruptedIOException;
import java.io.OutputStreamWriter;
import java.io.PrintStream;
import java.io.Reader;
import java.io.Writer;
import java.net.ServerSocket;
import java.net.Socket;

public class StreamTimeout {
    static final PrintStream log = System.err;
    static String charset = "US-ASCII";

    private static class Client extends Thread implements Closeable {
        private final Socket so;

        Client(int port) throws IOException {
            so = new Socket("127.0.0.1", port);
        }

        @Override
        public void run() {
            try {
                Writer wr = new OutputStreamWriter(so.getOutputStream(),
                        charset);
                wr.write("ab");
                wr.flush();
            } catch (IOException x) {
                log.print("Unexpected exception in writer: ");
                x.printStackTrace();
            }
        }

        @Override
        public void close() throws IOException {
            so.close();
        }
    }

    private static void gobble(InputStream is, Reader rd,
            int ec, boolean force)
                    throws Exception
                    {
        int a = is.available();
        boolean r = rd.ready();
        log.print("" + a + " bytes available, "
                + "reader " + (r ? "" : "not ") + "ready");
        if (!r && !force) {
            log.println();
            return;
        }
        int c;
        try {
            c = rd.read();
        } catch (InterruptedIOException x) {
            log.println();
            throw x;
        }
        log.println(", read() ==> "
                + (c >= 0 ? ("'" + (char)c + "'" ): "EOF"));
        if (c != ec)
            throw new Exception("Incorrect value read: Expected "
                    + ec + ", read " + (char)c);
    }

    public static void main(String[] args) throws Exception {

        if (args.length > 0)
            charset = args[0];

        try(ServerSocket ss = new ServerSocket(0);
            Client cl = new Client(ss.getLocalPort())) {

            cl.start();

            try(Socket s = ss.accept()) {
                s.setSoTimeout(150);

                try(InputStream is = s.getInputStream();
                    Reader rd = new InputStreamReader(is, charset)) {

                    while (is.available() <= 0)
                        Thread.yield();

                    gobble(is, rd, 'a', false);
                    gobble(is, rd, 'b', false);
                    gobble(is, rd, -1, false);

                    boolean caught = false;
                    try {
                        gobble(is, rd, -1, true);
                    } catch (InterruptedIOException e) {
                        log.println("Read timed out, as expected");
                        caught = true;
                    }
                    if (!caught) {
                        log.println("Read did not time out, test inapplicable");
                        return;
                    }

                    caught = false;
                    try {
                        gobble(is, rd, -1, true);
                    } catch (InterruptedIOException x) {
                        log.println("Second read timed out, as expected");
                        caught = true;
                    }
                    if (!caught)
                        throw new Exception("Second read completed");
                }
            }

            cl.join();
        }
    }
}