Package com.zebra.sdk.comm

Interface Connection

All Known Subinterfaces:
ConnectionWithWriteLogging, StatusConnection, StatusConnectionWithWriteLogging
All Known Implementing Classes:
ConnectionA, ConnectionStatusA, DriverPrinterConnection, MultichannelConnection, MultichannelRemoteConnection, MultichannelTcpConnection, MultichannelTlsConnection, RemoteConnection, RemoteStatusConnection, TcpConnection, TcpStatusConnection, TlsConnection, TlsStatusConnection, UsbConnection
public interface Connection
A connection to a device.

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    bytesAvailable()
    Returns an estimate of the number of bytes that can be read from this connection without blocking.
    void
    close()
    Closes this connection and releases any system resources associated with the connection.
    ConnectionReestablisher
    getConnectionReestablisher(long thresholdTime)
    Returns a ConnectionReestablisher which allows for easy recreation of a connection which may have been closed.
    int
    getMaxTimeoutForRead()
    Returns the maximum time, in milliseconds, to wait for any data to be received.
    String
    getSimpleConnectionName()
    Return a human-readable description of the connection.
    int
    getTimeToWaitForMoreData()
    Returns the maximum time, in milliseconds, to wait in-between reads after the initial read.
    boolean
    isConnected()
    Returns true if the connection is open.
    void
    open()
    Opens the connection to a device.
    byte[]
    read()
    Reads all the available data from the connection.
    void
    read(OutputStream destinationStream)
    Reads all the available data from the connection.
    int
    readChar()
    Reads the next byte of data from the connection, similar to a Java InputStream.
    byte[]
    sendAndWaitForResponse(byte[] dataToSend, int initialResponseTimeout, int responseCompletionTimeout, String terminator)
    Sends dataToSend and returns the response data.
    void
    sendAndWaitForResponse(OutputStream destinationStream, InputStream sourceStream, int initialResponseTimeout, int responseCompletionTimeout, String terminator)
    Sends data from sourceStream and writes the response data to destinationStream.
    byte[]
    sendAndWaitForValidResponse(byte[] dataToSend, int initialResponseTimeout, int responseCompletionTimeout, ResponseValidator validator)
    Sends dataToSend and returns the response data.
    void
    sendAndWaitForValidResponse(OutputStream destinationStream, InputStream sourceStream, int initialResponseTimeout, int responseCompletionTimeout, ResponseValidator validator)
    Sends data from sourceStream and writes the response data to destinationStream.
    void
    setMaxTimeoutForRead(int maxTimeoutForRead)
    Set the maximum time, in milliseconds, to wait for any data to be received
    void
    setTimeToWaitForMoreData(int timeToWaitForMoreData)
    Set the maximum time, in milliseconds, to wait in-between reads after the initial read.
    String
    toString()
    See the classes which implement this method for the format of the description string.
    void
    waitForData(int maxTimeout)
    Causes the currently executing thread to sleep until bytesAvailable() > 0, or for a maximum of maxTimeout milliseconds.
    void
    write(byte[] data)
    Writes data.length bytes from the specified byte array to this output stream.
    void
    write(byte[] data, int offset, int length)
    Writes length bytes from data starting at offset.
    void
    write(InputStream dataSource)
    Writes all available bytes from the data source to this output stream.

  • Method Details

    • open

      void open() throws ConnectionException
      Opens the connection to a device. If the open method is called when this connection has already been opened, this call is ignored. When a handle to the connection is no longer needed, you must call close() to free up system resources.
      Throws:
      ConnectionException - if the connection cannot be established.

    • close

      void close() throws ConnectionException
      Closes this connection and releases any system resources associated with the connection. If the connection is already closed then invoking this method has no effect.
      Throws:
      ConnectionException - if an I/O error occurs.

    • write

      void write(byte[] data) throws ConnectionException
      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.
      Parameters:
      data - the data.
      Throws:
      ConnectionException - if an I/O error occurs.
      See Also:

    • write

      void write(byte[] data, int offset, int length) throws ConnectionException
      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.
      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

      void write(InputStream dataSource) throws ConnectionException
      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.
      Parameters:
      dataSource - the data.
      Throws:
      ConnectionException - if an I/O error occurs.

    • read

      byte[] read() throws ConnectionException
      Reads all the available data from the connection. This call is non-blocking. 
       byte[] data = printerConnection.read();
      Returns:
      the bytes read from the connection.
      Throws:
      ConnectionException - if an I/O error occurs.

    • readChar

      int readChar() throws ConnectionException
      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();
      Returns:
      the next byte from the connection
      Throws:
      ConnectionException - if an I/O error occurs.

    • read

      void read(OutputStream destinationStream) throws ConnectionException
      Reads all the available data from the connection. This call is non-blocking.
      Parameters:
      destinationStream - for read data
      Throws:
      ConnectionException - if an I/O error occurs.

    • isConnected

      boolean isConnected()
      Returns true if the connection is open.
      Returns:
      true if this connection is open.

    • bytesAvailable

      int bytesAvailable() throws ConnectionException
      Returns an estimate of the number of bytes that can be read from this connection without blocking.
      Returns:
      estimated number of bytes available.
      Throws:
      ConnectionException - if an I/O error occurs.

    • toString

      String toString()
      See the classes which implement this method for the format of the description string.
      Overrides:
      toString in class Object
      Returns:
      the connection description string.

    • getSimpleConnectionName

      String getSimpleConnectionName()
      Return a human-readable description of the connection.
      Returns:
      a human-readable description of the connection.

    • waitForData

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

    • getMaxTimeoutForRead

      int getMaxTimeoutForRead()
      Returns the maximum time, in milliseconds, to wait for any data to be received.
      Returns:
      the maximum time, in milliseconds, to wait for any data to be received.

    • getTimeToWaitForMoreData

      int getTimeToWaitForMoreData()
      Returns the maximum time, in milliseconds, to wait in-between reads after the initial read.
      Returns:
      the maximum time, in milliseconds, to wait in-between reads after the initial read.

    • setMaxTimeoutForRead

      void setMaxTimeoutForRead(int maxTimeoutForRead)
      Set the maximum time, in milliseconds, to wait for any data to be received
      Parameters:
      maxTimeoutForRead - the maximum time, in milliseconds, to wait for any data to be received.

    • setTimeToWaitForMoreData

      void setTimeToWaitForMoreData(int timeToWaitForMoreData)
      Set the maximum time, in milliseconds, to wait in-between reads after the initial read.
      Parameters:
      timeToWaitForMoreData - the maximum time, in milliseconds, to wait in-between reads after the initial read.

    • sendAndWaitForResponse

      byte[] sendAndWaitForResponse(byte[] dataToSend, int initialResponseTimeout, int responseCompletionTimeout, String terminator) throws ConnectionException
      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.
      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.

    • sendAndWaitForResponse

      void sendAndWaitForResponse(OutputStream destinationStream, InputStream sourceStream, int initialResponseTimeout, int responseCompletionTimeout, String terminator) throws ConnectionException
      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.
      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.

    • sendAndWaitForValidResponse

      byte[] sendAndWaitForValidResponse(byte[] dataToSend, int initialResponseTimeout, int responseCompletionTimeout, ResponseValidator validator) throws ConnectionException
      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.
      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.

    • sendAndWaitForValidResponse

      void sendAndWaitForValidResponse(OutputStream destinationStream, InputStream sourceStream, int initialResponseTimeout, int responseCompletionTimeout, ResponseValidator validator) throws ConnectionException
      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.
      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.

    • getConnectionReestablisher

      ConnectionReestablisher getConnectionReestablisher(long thresholdTime) throws ConnectionException
      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).
      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.