Java example source code file (Write.java)

This example Java source code file (Write.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

bytebuffer, exception, failed, inetaddress, inetsocketaddress, ioexception, net, network, nio, random, serversocketchannel, socketchannel, string, testthread, util, writeserver

The Write.java Java example source code

/*
 * Copyright (c) 2003, 2010, 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 4854354
 * @summary Test vector write faster than can be read
 * @library ..
 */

import java.io.*;
import java.net.*;
import java.nio.*;
import java.nio.channels.*;
import java.util.*;
import sun.misc.*;


public class Write {

    static Random generator = new Random();

    static int testSize = 15;

    public static void main(String[] args) throws Exception {
        WriteServer sv = new WriteServer();
        sv.start();
        bufferTest(sv.port());
        if (sv.finish(8000) == 0)
            throw new Exception("Failed" );
    }

    static void bufferTest(int port) throws Exception {
        ByteBuffer[] bufs = new ByteBuffer[testSize];
        for(int i=0; i<testSize; i++) {
            String source =
                "a muchmuchmuchmuchmuchmuchmuchmuch larger buffer numbered " +
                i;
            bufs[i] = ByteBuffer.allocateDirect(source.length());
        }

        // Get a connection to the server
        InetAddress lh = InetAddress.getLocalHost();
        InetSocketAddress isa = new InetSocketAddress(lh, port);
        SocketChannel sc = SocketChannel.open();
        sc.connect(isa);
        sc.configureBlocking(false);

        // Try to overflow the socket buffer
        long total = 0;
        for (int i=0; i<100; i++) {
            long bytesWritten = sc.write(bufs);
            if (bytesWritten > 0)
                total += bytesWritten;
            for(int j=0; j<testSize; j++)
                bufs[j].rewind();
        }

        // Clean up
        sc.close();
    }

}


class WriteServer extends TestThread {

    static Random generator = new Random();


    final ServerSocketChannel ssc;

    WriteServer() throws IOException {
        super("WriteServer");
        this.ssc = ServerSocketChannel.open().bind(new InetSocketAddress(0));
    }

    int port() {
        return ssc.socket().getLocalPort();
    }

    void go() throws Exception {
        bufferTest();
    }

    void bufferTest() throws Exception {
        ByteBuffer buf = ByteBuffer.allocateDirect(5);

        // Get a connection from client
        SocketChannel sc = null;

        try {
            ssc.configureBlocking(false);

            for (;;) {
                sc = ssc.accept();
                if (sc != null)
                    break;
                Thread.sleep(50);
            }

            // I'm a slow reader...
            Thread.sleep(3000);

        } finally {
            // Clean up
            ssc.close();
            if (sc != null)
                sc.close();
        }

    }

}