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"IOException: try again" when using LocalServerSocket

Does anyone have more useful information about the Try Again exception?

I am sending bitmaps between applications using LocalServerSocketand LocalSocket:

Conclusion:

socket = new LocalSocket();
socket.connect(new LocalSocketAddress(SOCKET_NAME));
fos = new DataOutputStream(socket.getOutputStream());
...

public void onEvent() {
    fos.writeInt(width);
    fos.writeInt(height);
    fos.writeInt(newBuffer.length);
    fos.write(newBuffer);
}

Input:

server = new LocalServerSocket(SOCKET_NAME);
socket = server.accept(); 
socket.setSoTimeout(60);

while(true) {

    int width = fis.readInt(); // IO Exception being thrown here
    int height = fis.readInt(); 
    int length = fis.readInt();
    byte[] bytes = new byte[length];
    fis.read(bytes);
}

[try / catch, etc. removed for clarity]

04-18 09:19:11.664: W/System.err(1268): java.io.IOException: Try again
04-18 09:19:11.664: W/System.err(1268):     at android.net.LocalSocketImpl.readba_native(Native Method)
04-18 09:19:11.664: W/System.err(1268):     at android.net.LocalSocketImpl.access$400(LocalSocketImpl.java:29)
04-18 09:19:11.664: W/System.err(1268):     at android.net.LocalSocketImpl$SocketInputStream.read(LocalSocketImpl.java:92)
04-18 09:19:11.664: W/System.err(1268):     at libcore.io.Streams.readFully(Streams.java:81)
04-18 09:19:11.664: W/System.err(1268):     at java.io.DataInputStream.readInt(DataInputStream.java:124)
04-18 09:19:11.664: W/System.err(1268):     at com.test.util.BitmapSendingUtils$BitmapReceiver$1.run(BitmapSendingUtils.java:105)
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5 answers

The exception you see is probably equivalent to the java EAGAIN error. See for example this answer .

You must handle the exception and retry the failed I / O operation.

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Since then I have edited this since I could not find a solution. But, introducing it in another way, I met these errors in the source code:

byte[] bytes = new byte[length];
fis.read(bytes);

:

byte[] content = new byte[length];
int read = is.read(content);
while(read < content.length) {
    read += is.read(content, read, content.length - read);
}

.read(byte[]) . , , .

:

socket.setSoTimeout(60);

, , :

socket.setSoTimeout(60 * 1000);

, , , - , !

+3

, mInputValid , :

private int fill(byte[] buffer, int offset,int length) throws IOException {
    int sum = 0, len;
    while ((sum<length) && mInputValid) {
        try{
            len = is.read(buffer, offset + sum, length - sum);
            if (len < 0) {
                throw new IOException("End of stream");
            } else{
                sum += len;
                Log.i(TAG, "is.read: " + len + " buffer:" + buffer[0]);
            }
        }
        catch (IOException e){
            e.printStackTrace();
            Log.i(TAG, "read input fail, try again");
            continue;
        }
    }
    return sum;
}
0

, "Try again" IOException , SocketTimeoutException. API, Android:

private int read(byte[] buffer) throws IOException {

    while (true) {
        try {
            return fis.read(buffer);
        } catch (SocketTimeoutException e) {
            continue;
        } catch (IOException e) {
            String message = e.getMessage();
            if (message != null && message.equals("Try again")) {
                continue;
            }
            throw e;
        }
    }
}

private int readInt() throws IOException {
    while (true) {
        try {
            return fis.readInt();
        } catch (SocketTimeoutException e) {
            continue;
        } catch (IOException e) {
            String message = e.getMessage();
            if (message != null && message.equals("Try again")) {
                continue;
            }
            throw e;
        }
    }
}
0

, , , , :

  • outputStream.flush() . , writer.flush(). . , , . , , , , - , , int.
  • , : Java , - reader.read(buffer), buffer . (, - , , ).
  • If you close streams after sending a message and cause it output.flush(), this exception may be caused by what you had in mind: socket timeouts, as well as disconnections.
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