Package com.zebra.sdk.comm

Class MultichannelConnection

Object
com.zebra.sdk.comm.MultichannelConnection
All Implemented Interfaces:
Connection, ConnectionWithWriteLogging
Direct Known Subclasses:
MultichannelRemoteConnection, MultichannelTcpConnection, MultichannelTlsConnection
public abstract class MultichannelConnection extends Object implements ConnectionWithWriteLogging
Base class for Link-OS printers which support separate printing and status channels. This class conforms to a standard Connection and if only the Connection methods are used, the SDK will attempt to open both the printing and status channels. MultichannelConnection will use the raw Connection when a method is called directly. Furthermore, when using a ZebraPrinterLinkOs in conjunction with a MultichannelConnection, the ZebraPrinterLinkOs will attempt to use whichever connection is the most efficient. If you wish to only open up a specific channel, use either the openPrintingChannel() or openStatusChannel() method and their corresponding closePrintingChannel() and closeStatusChannel() method.

  • Method Details

    • open

      public void open() throws ConnectionException
      Opens both the printing and status channel of this Multichannel connection. If neither channel can be opened, then a ConnectionException is thrown. When this Multichannel connection is no longer needed, you must call Connection.close() to free up system resources.
      Specified by:
      open in interface Connection
      Throws:
      ConnectionException - if the connection cannot be established.

    • openPrintingChannel

      public void openPrintingChannel() throws ConnectionException
      Opens the printing channel of this Multichannel connection. If this method is called when this channel has already been opened, the call is ignored. When this channel is no longer needed, you must call either Connection.close() or closePrintingChannel() to free up system resources.
      Throws:
      ConnectionException - if the connection cannot be established.

    • openStatusChannel

      public void openStatusChannel() throws ConnectionException
      Opens the status channel of this Multichannel connection. If this method is called when this channel has already been opened, the call is ignored. When this channel is no longer needed, you must call either Connection.close() or closeStatusChannel() to free up system resources.
      Throws:
      ConnectionException

    • close

      public void close() throws ConnectionException
      Closes both the printing and status channels of this MultichannelConnection. Releases any system resources associated with the connection. If the connection is already closed then invoking this method has no effect.
      Specified by:
      close in interface Connection
      Throws:
      ConnectionException - if an I/O error occurs.

    • closePrintingChannel

      public void closePrintingChannel() throws ConnectionException
      Closes the printing channel of this MultichannelConnection. Releases any system resources associated with the channel. If the channel is already closed then invoking this method has no effect.
      Throws:
      ConnectionException - if an I/O error occurs.

    • closeStatusChannel

      public void closeStatusChannel() throws ConnectionException
      Closes the status channel of this MultichannelConnection. Releases any system resources associated with the channel. If the channel is already closed then invoking this method has no effect.
      Throws:
      ConnectionException - if an I/O error occurs.

    • write

      public void write(byte[] data) throws ConnectionException
      Description copied from interface: Connection
      Writes data.length bytes from the specified byte array to this output stream. The connection must be open before this method is called. If write is called when a connection is closed, a ConnectionException is thrown.
      Specified by:
      write in interface Connection
      Parameters:
      data - the data.
      Throws:
      ConnectionException - if an I/O error occurs.
      See Also:

    • write

      public void write(byte[] data, int offset, int length) throws ConnectionException
      Description copied from interface: Connection
      Writes length bytes from data starting at offset. The connection must be open before this method is called. If write is called when a connection is closed, a ConnectionException is thrown.
      Specified by:
      write in interface Connection
      Parameters:
      data - the data.
      offset - the start offset in the data.
      length - number of bytes to write.
      Throws:
      ConnectionException - if an I/O error occurs.
      See Also:

    • write

      public void write(InputStream dataSource) throws ConnectionException
      Description copied from interface: Connection
      Writes all available bytes from the data source to this output stream. The connection must be open before this method is called. If write is called when a connection is closed, a ConnectionException is thrown.
      Specified by:
      write in interface Connection
      Parameters:
      dataSource - the data.
      Throws:
      ConnectionException - if an I/O error occurs.
      See Also:

    • read

      public byte[] read() throws ConnectionException
      Description copied from interface: Connection
      Reads all the available data from the connection. This call is non-blocking. 
       byte[] data = printerConnection.read();
      Specified by:
      read in interface Connection
      Returns:
      the bytes read from the connection.
      Throws:
      ConnectionException - if an I/O error occurs.
      See Also:

    • read

      public void read(OutputStream destinationStream) throws ConnectionException
      Description copied from interface: Connection
      Reads all the available data from the connection. This call is non-blocking.
      Specified by:
      read in interface Connection
      Parameters:
      destinationStream - for read data
      Throws:
      ConnectionException - if an I/O error occurs.
      See Also:

    • readChar

      public int readChar() throws ConnectionException
      Description copied from interface: Connection
      Reads the next byte of data from the connection, similar to a Java InputStream. The value byte is returned as an int in the range of 0 to 255. If no byte is available on the connection the value -1 is returned. 
       int singleCharacter = printerConnection.readChar();
      Specified by:
      readChar in interface Connection
      Returns:
      the next byte from the connection
      Throws:
      ConnectionException - if an I/O error occurs.
      See Also:

    • isConnected

      public boolean isConnected()
      Description copied from interface: Connection
      Returns true if the connection is open.
      Specified by:
      isConnected in interface Connection
      Returns:
      true if this connection is open.
      See Also:

    • bytesAvailable

      public int bytesAvailable() throws ConnectionException
      Description copied from interface: Connection
      Returns an estimate of the number of bytes that can be read from this connection without blocking.
      Specified by:
      bytesAvailable in interface Connection
      Returns:
      estimated number of bytes available.
      Throws:
      ConnectionException - if an I/O error occurs.
      See Also:

    • waitForData

      public void waitForData(int maxTimeout) throws ConnectionException
      Description copied from interface: Connection
      Causes the currently executing thread to sleep until Connection.bytesAvailable() > 0, or for a maximum of maxTimeout milliseconds.
      Specified by:
      waitForData in interface Connection
      Parameters:
      maxTimeout - maximum time in milliseconds to wait for an initial response from the printer.
      Throws:
      ConnectionException - if an I/O error occurs.
      See Also:

    • getMaxTimeoutForRead

      public int getMaxTimeoutForRead()
      Returns the maximum time, in milliseconds, to wait for any data to be received on the printing channel.
      Specified by:
      getMaxTimeoutForRead in interface Connection
      Returns:
      the maximum time, in milliseconds, to wait for any data to be received.

    • getTimeToWaitForMoreData

      public int getTimeToWaitForMoreData()
      Returns the maximum time, in milliseconds, to wait in-between reads after the initial read for the printing channel.
      Specified by:
      getTimeToWaitForMoreData in interface Connection
      Returns:
      the maximum time, in milliseconds, to wait in-between reads after the initial read.

    • setMaxTimeoutForRead

      public void setMaxTimeoutForRead(int maxTimeoutForRead)
      Set the maximum time, in milliseconds, to wait for any data to be received. This sets the timeout for the printing and status channels.
      Specified by:
      setMaxTimeoutForRead in interface Connection
      Parameters:
      maxTimeoutForRead - the maximum time, in milliseconds, to wait for any data to be received.

    • setTimeToWaitForMoreData

      public void setTimeToWaitForMoreData(int timeToWaitForMoreData)
      Set the maximum time, in milliseconds, to wait in-between reads after the initial read. This sets the timeout for the printing and status channels.
      Specified by:
      setTimeToWaitForMoreData in interface Connection
      Parameters:
      timeToWaitForMoreData - the maximum time, in milliseconds, to wait in-between reads after the initial read.

    • sendAndWaitForResponse

      public byte[] sendAndWaitForResponse(byte[] dataToSend, int initialResponseTimeout, int responseCompletionTimeout, String terminator) throws ConnectionException
      Description copied from interface: Connection
      Sends dataToSend and returns the response data. The software returns immediately if the data received contains terminator. The connection must be open before this method is called. If sendAndWaitForResponse is called when a connection is closed, a ConnectionException is thrown.
      Specified by:
      sendAndWaitForResponse in interface Connection
      Parameters:
      dataToSend - byte array of data to send
      initialResponseTimeout - The maximum time, in milliseconds, to wait for the initial response to be received. If no data is received during this time, the function returns a zero length array.
      responseCompletionTimeout - After the initial response, if no data is received for this period of time, the input is considered complete and the method returns.
      terminator - If the response contains this string, the input is considered complete and the method returns. May be used to avoid waiting for more data when the response is always terminated with a known string. Use null if no terminator is desired.
      Returns:
      received data
      Throws:
      ConnectionException - if an I/O error occurs.
      See Also:

    • sendAndWaitForResponse

      public void sendAndWaitForResponse(OutputStream destinationStream, InputStream sourceStream, int initialResponseTimeout, int responseCompletionTimeout, String terminator) throws ConnectionException
      Description copied from interface: Connection
      Sends data from sourceStream and writes the response data to destinationStream. The software returns immediately if the data received contains terminator. The connection must be open before this method is called. If sendAndWaitForResponse is called when a connection is closed, a ConnectionException is thrown.
      Specified by:
      sendAndWaitForResponse in interface Connection
      Parameters:
      destinationStream - Destination for response.
      sourceStream - Source of data to be sent.
      initialResponseTimeout - The maximum time, in milliseconds, to wait for the initial response to be received. If no data is received during this time, the function does not write any data to the destination stream.
      responseCompletionTimeout - After the initial response, if no data is received for this period of time, the input is considered complete and the method returns.
      terminator - If the response contains this string, the input is considered complete and the method returns. May be used to avoid waiting for more data when the response is always terminated with a known string. Use null if no terminator is desired.
      Throws:
      ConnectionException - if an I/O error occurs.
      See Also:

    • sendAndWaitForValidResponse

      public byte[] sendAndWaitForValidResponse(byte[] dataToSend, int initialResponseTimeout, int responseCompletionTimeout, ResponseValidator validator) throws ConnectionException
      Description copied from interface: Connection
      Sends dataToSend and returns the response data. The software returns immediately if the data received satisfies validator. The connection must be open before this method is called. If sendAndWaitForResponse is called when a connection is closed, a ConnectionException is thrown.
      Specified by:
      sendAndWaitForValidResponse in interface Connection
      Parameters:
      dataToSend - byte array of data to send
      initialResponseTimeout - The maximum time, in milliseconds, to wait for the initial response to be received. If no data is received during this time, the function returns a zero length array.
      responseCompletionTimeout - After the initial response, if no data is received for this period of time, the input is considered complete and the method returns.
      validator - If the response satisfies this validator, the input is considered complete and the method returns. May be used to avoid waiting for more data when the response follows a known format.
      Returns:
      received data
      Throws:
      ConnectionException - if an I/O error occurs.
      See Also:

    • sendAndWaitForValidResponse

      public void sendAndWaitForValidResponse(OutputStream destinationStream, InputStream sourceStream, int initialResponseTimeout, int responseCompletionTimeout, ResponseValidator validator) throws ConnectionException
      Description copied from interface: Connection
      Sends data from sourceStream and writes the response data to destinationStream. The software returns immediately if the data received satisfies validator. The connection must be open before this method is called. If sendAndWaitForResponse is called when a connection is closed, a ConnectionException is thrown.
      Specified by:
      sendAndWaitForValidResponse in interface Connection
      Parameters:
      destinationStream - Destination for response.
      sourceStream - Source of data to be sent.
      initialResponseTimeout - The maximum time, in milliseconds, to wait for the initial response to be received. If no data is received during this time, the function does not write any data to the destination stream.
      responseCompletionTimeout - After the initial response, if no data is received for this period of time, the input is considered complete and the method returns.
      validator - If the response satisfies this validator, the input is considered complete and the method returns. May be used to avoid waiting for more data when the response follows a known format. If validator is null, no validation is performed. When performing validation, this method will use enough memory to hold the entire response.
      Throws:
      ConnectionException - if an I/O error occurs.
      See Also:

    • getPrintingChannel

      public Connection getPrintingChannel()
      Returns the underlying printing Connection of this MultichannelConnection.
      Returns:
      the printing channel.

    • getStatusChannel

      public StatusConnection getStatusChannel()
      Returns the underlying status StatusConnection of this MultichannelConnection.
      Returns:
      the status channel.

    • getConnectionReestablisher

      public ConnectionReestablisher getConnectionReestablisher(long thresholdTime) throws ConnectionException
      Description copied from interface: Connection
      Returns a ConnectionReestablisher which allows for easy recreation of a connection which may have been closed.
      • This call should be made while there is still an active connection to the printer (prior to issuing a command which will make the printer non-responsive).
      Specified by:
      getConnectionReestablisher in interface Connection
      Parameters:
      thresholdTime - how long the Connection reestablisher will wait before attempting to reconnection to the printer
      Returns:
      ConnectionReestablisher
      Throws:
      ConnectionException - if the ConnectionReestablisher could not be created.
      See Also:

    • addWriteLogStream

      public void addWriteLogStream(OutputStream logStream)
      Description copied from interface: ConnectionWithWriteLogging
      Adds the OutputStream to the connection to log all data written to the connected device.
      Specified by:
      addWriteLogStream in interface ConnectionWithWriteLogging
      Parameters:
      logStream - log all write data to this stream.
      See Also: