Re: [xSocket-develop] basic question about read data from readByteBufferByDelimiter

[beijing w. <wel...@gm...>]

2008/10/30 Gregor Roth <gre...@go...>

> take a look into xSocket's Junit test:
>  -
> http://xlightweb.svn.sourceforge.net/viewvc/xlightweb/xlightweb/core/trunk/src/test/java/org/xlightweb/CommandStreamingTest.java?view=markup
>  -
> http://xlightweb.svn.sourceforge.net/viewvc/xlightweb/xlightweb/core/trunk/src/test/java/org/xlightweb/ChannelStreamingTest.java?view=markup
>


>
> May be it helps you.


I changed the code to transfer the file, have further problem when write
file, see inline.



>
>
> Gregor
>
>
> 2008/10/30 beijing welcome <wel...@gm...>
>
>
>>
>> 2008/10/30 Gregor Roth <gre...@go...>
>>
>>> … you do two things in our onData() implementation: Echoing the received
>>> data and printing it.
>>>
>>> If you are using the async flush mode, the buffer will be written to the
>>> network asynchronously by the internal I/O thread. This means by returning
>>> from the write method the buffer will be accessed by the I/O thread in the
>>> background in a concurrent way. Because you access the buffer after the
>>> write call to print it race conditions occurs. The solution is to duplicate
>>> the byte buffer by calling <ByteBuffer>.duplicate() method or not to set the
>>> flush mode to async.
>>>
>> thanks for your quick response.
>> oh, i just want to let server receive the stream and then send another
>> stream back to client, the solution above may hurt something, what's the
>> most effective method to do that?
>> onData() seems not the correct place to implement this logical, could you
>> please point me which interface should be the right one?
>>
>>
>>>
>>> Converting byte buffers to a string is a little bit tricky. You can use
>>> the convenience method DataConverter.toString(<ByteBuffer[]>, encoding) to
>>> convert the byte buffers to a string.
>>>
>>> Gregor
>>>
>>>
>>>
>>> 2008/10/29 beijing welcome <wel...@gm...>
>>>
>>>>  hi, xSocket develop folks,
>>>>
>>>> This might be a very basic question, I want to read a file by stream and
>>>> send to server, then do something, however, ByteBuffer[] in
>>>> readByteBufferByDelimiter is empty in server side.
>>>>
>>>> paste the code below.
>>>>
>>>> Thank you in advance!
>>>>
>>>> =============== MServer.java ==============
>>>> package mserver;
>>>>
>>>> import java.io.Closeable;
>>>> import java.io.IOException;
>>>> import java.net.InetAddress;
>>>> import java.util.HashSet;
>>>> import java.util.Set;
>>>>
>>>> import org.xsocket.connection.IConnectHandler;
>>>> import org.xsocket.connection.IHandler;
>>>> import org.xsocket.connection.INonBlockingConnection;
>>>> import org.xsocket.connection.IServer;
>>>> import org.xsocket.connection.Server;
>>>> import org.xsocket.connection.ConnectionUtils;
>>>> import org.xsocket.connection.IConnection.FlushMode;
>>>>
>>>> import mserver.MServerHandler;
>>>>
>>>>
>>>> public class MServer implements Closeable {
>>>>
>>>>     private IServer server = null;
>>>>
>>>>     public MServer(int listenPort) throws Exception {
>>>>
>>>>         IHandler hdl = new MServerHandler();
>>>>
>>>>         server = new Server(listenPort, hdl);
>>>>         server.setFlushMode(FlushMode.ASYNC);  // performance
>>>> improvement
>>>>
>>>>         ConnectionUtils.start(server);
>>>>         ConnectionUtils.registerMBean(server);
>>>>     }
>>>>
>>>>     public static void main(String... args) throws Exception {
>>>>         int port = 8888;
>>>>         new MServer(port);
>>>>     }
>>>>
>>>>     public InetAddress getLocalAddress() {
>>>>         return server.getLocalAddress();
>>>>     }
>>>>
>>>>     public void close() throws IOException {
>>>>         if (server != null) {
>>>>             server.close();
>>>>         }
>>>>     }
>>>>
>>>> }
>>>> ==============================================
>>>>
>>>> =================== MServerHandler.java ===========================
>>>>
>>>> package mserver;
>>>>
>>>> import java.io.IOException;
>>>> import java.nio.BufferUnderflowException;
>>>> import java.nio.ByteBuffer;
>>>> import java.nio.CharBuffer;
>>>> import java.nio.charset.Charset;
>>>> import java.nio.charset.CharsetDecoder;
>>>>
>>>> import org.xsocket.Execution;
>>>> import org.xsocket.MaxReadSizeExceededException;
>>>> import org.xsocket.connection.IConnectHandler;
>>>> import org.xsocket.connection.IDataHandler;
>>>> import org.xsocket.connection.INonBlockingConnection;
>>>> import org.xsocket.connection.IConnection.FlushMode;
>>>>
>>>> @Execution(Execution.NONTHREADED)
>>>> public class MServerHandler implements IConnectHandler, IDataHandler {
>>>>     public static final String DELIMITER = "\r\n";
>>>>     static Charset charset = Charset.forName("gb2312");
>>>>     static CharsetDecoder decoder = charset.newDecoder();
>>>>     static CharBuffer charBuffer = null ;
>>>>
>>>>     public boolean onConnect(INonBlockingConnection connection) throws
>>>> IOException, BufferUnderflowException, MaxReadSizeExceededException {
>>>>         connection.setFlushmode(FlushMode.ASYNC);
>>>>         connection.setAutoflush(false);
>>>> //        connection.write("Welcome to MServer!");
>>>>         System.out.println(connection.getRemoteAddress() + "
>>>> connected!");
>>>>         return true;
>>>>     }
>>>>
>>>>     public boolean onData(INonBlockingConnection connection) throws
>>>> IOException, BufferUnderflowException {
>>>>         ByteBuffer[] buffer =
>>>> connection.readByteBufferByDelimiter(DELIMITER, Integer.MAX_VALUE);
>>>> //        connection.write("Server: ");
>>>>
>>>>         connection.write(buffer);
>>>>         connection.write(DELIMITER);
>>>>         for (int j = 0; j < buffer.length; ++j) {
>>>>             buffer[j].flip();
>>>>             charBuffer = decoder.decode(buffer[j]);
>>>> //          System.out.println( " charBuffer= "   +  charBuffer);
>>>>        // this line is empty!
>>>>           System.out.println(charBuffer.toString());
>>>>             System.out.println(j);
>>>>         }
>>>>         connection.flush();
>>>>         System.out.println("====");
>>>>         return true;
>>>>     }
>>>> }
>>>>
>>>
I changed the code followed:

    public boolean onData(INonBlockingConnection connection) throws
IOException, BufferUnderflowException {
        if (connection.available() < 0) return false;
        File file = File.createTempFile("test", null);
        System.out.println("avaliable1: " + connection.available());
// "hello" can be received successfully.
        String s = connection.readStringByDelimiter(DELIMITER);
        System.out.println(s);
        file.createNewFile();
        //file.deleteOnExit();
        String fullname = file.getAbsolutePath();
        System.out.println("fullname: " + fullname);
        System.out.println("avaliable2: " + connection.available());
        FileChannel fc = new FileOutputStream(file).getChannel();
        long length = fc.transferTo(0, connection.available(), connection);
*        // !!! This line cannot be run???*
        System.out.println(length);
        fc.close();
        connection.write(fc.size());
        connection.flush();

        System.out.println("====");
        return true;
    }


the server side output is:
/127.0.0.1 connected!
avaliable1: 179
hello
fullname: C:\DOCUME~1\bati\LOCALS~1\Temp\test25638.tmp
avaliable2: 172
avaliable1: -1

however, C:\DOCUME~1\bati\LOCALS~1\Temp\test25638.tmp is empty! I may miss
something.


>>>>
>>>>
>>>> =========================================
>>>> ================= MServerClient.java ========================
>>>> package mserver;
>>>>
>>>> import java.io.InputStreamReader;
>>>> import java.io.LineNumberReader;
>>>> import java.net.Socket;
>>>>
>>>> public class MServerClient {
>>>>
>>>     static String filename = "c:\\111.txt";
    public void startClient() throws Exception {
        int port = 8888;
        String host = "localhost";
        INonBlockingConnection connection = null;
        try {
            connection = new NonBlockingConnection(host, port);
            connection.write("hello\r\n");
            FileChannel fc = new FileInputStream(filename).getChannel();
            connection.transferFrom(fc);
            fc.close();
            System.out.println("done!");
        } catch (Exception e) {
            e.printStackTrace();
        }
        finally {
            if (connection != null) {
                connection.close();
            }
        }

    }
>>>>     /**
>>>>      * @param args
>>>>      */
>>>>     public static void main(String[] args) {
>>>>         // TODO Auto-generated method stub
>>>>         MServerClient client = new MServerClient();
>>>>         try {
>>>>             client.startClient();
>>>>         } catch (Exception e) {
>>>>             e.printStackTrace();
>>>>         }
>>>>     }
>>>>
>>>> }
>>>>
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>>>>
>>>
>>
>