com.bensherman.rtlsdrdjava.tcpcli

Class TcpSocketReader

java.lang.Object

com.bensherman.rtlsdrdjava.tcpcli.TcpSocketReader

All Implemented Interfaces:

java.lang.Runnable

class TcpSocketReader
extends java.lang.Object
implements java.lang.Runnable

Field Summary

Fields

Modifier and Type	Field and Description
private static java.lang.String	BEGIN_SUCCESSFUL_RESPONSE
private static java.lang.String	END_OF_RESPONSE
private boolean	keepAlive True if this thread should continue, false if it should terminate
private java.util.Queue<Message>	msgsWaitingForResponseQueue Queue of messages which are waiting for their associated responses to be received from the server
private java.io.BufferedReader	socketBufferedReader BufferedReader used to read from the socket
private TcpClient	tcpClient The TcpClient which instantiated this TcpSocketReader
private static java.lang.String	UPDATE_AVAILABLE_STRING_PREFIX

Constructor Summary

Constructors

Constructor and Description
TcpSocketReader(java.net.Socket socket, TcpClient tcpClient) Constructs a TcpSocketReader

Method Summary

Modifier and Type	Method and Description
(package private) void	addToWaitingForResponseQueue(Message msgNeedingResponse) Adds the message specified by the parameter to the queue of messages which are waiting for a response.
private void	addUpdateAvailableMsgToCompletedQueue(java.lang.String msg) Handler for UPDATE_AVAILABLE being received.
(package private) Message	getResponseFromSocket() Each call to this function is intended to build a response for the oldest message which hasn't been responded to.
private void	logMsg(java.lang.String msg) Logs/outputs a message.
(package private) Message	pollMostRecentlyRespondedToMsgAndSetResponse(java.lang.String response, Message.ResponseType responseMsgType) Executes poll() on msgsWaitingForResponseQueue, which should always contain at least one Message when this function is executed.
(package private) void	requestStop() Sets the keepAlive boolean to false, so that if this thread is interrupted or the socket is closed, the thread will die.
void	run() The function called when a new TcpSocketReader thread is executed.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

BEGIN_SUCCESSFUL_RESPONSE

private static final java.lang.String BEGIN_SUCCESSFUL_RESPONSE

See Also:

Constant Field Values

END_OF_RESPONSE

private static final java.lang.String END_OF_RESPONSE

See Also:

Constant Field Values

UPDATE_AVAILABLE_STRING_PREFIX

private static final java.lang.String UPDATE_AVAILABLE_STRING_PREFIX

See Also:

Constant Field Values

socketBufferedReader

private final java.io.BufferedReader socketBufferedReader

BufferedReader used to read from the socket

msgsWaitingForResponseQueue

private final java.util.Queue<Message> msgsWaitingForResponseQueue

Queue of messages which are waiting for their associated responses to be received from the server

keepAlive

private boolean keepAlive

True if this thread should continue, false if it should terminate

tcpClient

private final TcpClient tcpClient

The TcpClient which instantiated this TcpSocketReader

Constructor Detail

TcpSocketReader

TcpSocketReader(java.net.Socket socket,
                TcpClient tcpClient)
         throws java.io.IOException

Constructs a TcpSocketReader

Parameters:

socket - A socket which is connected to the server

tcpClient - The TcpClient which instantiated this TcpSocketReader

Throws:

java.io.IOException - If an error occurs when attempting to call getInputStream() on the socket param

Method Detail

addToWaitingForResponseQueue

void addToWaitingForResponseQueue(Message msgNeedingResponse)

Adds the message specified by the parameter to the queue of messages which are waiting for a response. The add() call is synchronized using the msgsWaitingForResponseQueue

Parameters:

msgNeedingResponse - The message whose response is requested

pollMostRecentlyRespondedToMsgAndSetResponse

Message pollMostRecentlyRespondedToMsgAndSetResponse(java.lang.String response,
                                                     Message.ResponseType responseMsgType)

Executes poll() on msgsWaitingForResponseQueue, which should always contain at least one Message when this function is executed. After the Message is pulled from the queue, and the specified parameters are set.

Parameters:

response - The responseMsg field's value to be set

responseMsgType - The responseMsgType field's value to be set

Returns:

See description

run

public void run()

The function called when a new TcpSocketReader thread is executed. This function will listen to the output from the server, and will update Message instances created by the TcpSocketWriter thread with their associated responses. When an response indicating an update is available or an error occurred, the getResponseFromSocket() thread will perform an action WHICH MUST BE DEFINED.

Specified by:

run in interface java.lang.Runnable

getResponseFromSocket

Message getResponseFromSocket()
                       throws java.io.IOException

Each call to this function is intended to build a response for the oldest message which hasn't been responded to. This function will build the response message as well as determine its type. Once the END_OF_RESPONSE specifier has been received, the last not-responded-to message is retrieved (and removed from the queue), it's responseMsg and responseMsgType fields are set,and it's returned to the caller. The server can return an OK or ERROR response. Also, it can return an UPDATE_AVAILABLE specifier asynchronously, in the middle of the current response being generated. In this case, the response string isn't updated with the UPDATE_AVAILABLE specifier. Instead, the user of this library MUST define the appropriate action for when such a message is received. The location where this application-specific change is to be made is in the comments below. For sake of example, a basic handler for the UPDATE_AVAILABLE mesasge has been implemented (addUpdateAvailableMsgToCompletedQueue()). When UPDATE_AVAILABLE is received, a Message associated with it will be added to the completed queue, but this function will not return; instead, it'll keep processing the current response being build. This function may be terminated due to an IOException being thrown when the underlying socket is closed.

Returns:

The oldest not-responded-to message with set response and response type fields.

Throws:

java.io.IOException - When an error has occurred when reading the socket.

java.lang.IllegalStateException - If the new response specifier is sent before the response being built is complete.

addUpdateAvailableMsgToCompletedQueue

private void addUpdateAvailableMsgToCompletedQueue(java.lang.String msg)

Handler for UPDATE_AVAILABLE being received. This function creates a new Message with a blank "outboundMsg" field, response type of UPDATE_AVAILABLE, and responseMessage of the msg parameter (which is expected to be the UPDATE_AVAILABLE + timestamp string from rtlsdrd). The listener to the completed message queue can handle this message type appropriately.

Parameters:

msg - The UPDATE_AVAILABLE + timestamp string from rtlsdrd

logMsg

private void logMsg(java.lang.String msg)

Logs/outputs a message. Replace the System.out.println() with a logger if desired. The message format is ": msg"

Parameters:

msg - The msg to log

requestStop

void requestStop()

Sets the keepAlive boolean to false, so that if this thread is interrupted or the socket is closed, the thread will die.