com.zebra.sdk.remote.comm

Class RemoteConnection

Object

com.zebra.sdk.comm.ConnectionA

com.zebra.sdk.remote.comm.RemoteConnection

All Implemented Interfaces:

Connection, ConnectionWithWriteLogging

public class RemoteConnection
extends ConnectionA

This class provides access to remotely connected devices. When implementing the API on a server which is running a Zebra servlet instance the user may use this class to interact with remotely connected devices in the same manner they would any other Connection type.

package test.zebra.sdk.comm.examples;
 
 import com.zebra.sdk.comm.Connection;
 import com.zebra.sdk.comm.ConnectionException;
 import com.zebra.sdk.printer.ZebraPrinter;
 import com.zebra.sdk.printer.ZebraPrinterFactory;
 import com.zebra.sdk.printer.ZebraPrinterLanguageUnknownException;
 import com.zebra.sdk.remote.comm.RemoteConnection;
 
 public class RemoteConnectionExample {
 
     // This example assumes Link-OS printers are connected via Web Sockets to a server which is running a Zebra servlet
     // instance.
     public static void main(String[] args) throws Exception {
         new RemoteConnectionExample().sendZplOverTcp("myPrinterUUID");
         new RemoteConnectionExample().printConfigLabelUsingDnsName("myPrinterUUID");
     }
 
     private void sendZplOverTcp(String theUniqueId) throws ConnectionException {
         // Instantiate a remote connection to the printer specified by UUID using the default Zebra Web services
         // port (11995).
         // Note: The printer must be connected to a server which is running a Zebra servlet instance.
         Connection connection = new RemoteConnection(theUniqueId);
         try {
             // Open the connection - physical connection is established here.
             connection.open();
 
             // This example prints "This is a ZPL test." near the top of the label.
             String zplData = "^XA^FO20,20^A0N,25,25^FDThis is a ZPL test.^FS^XZ";
 
             // Send the data to printer as a byte array.
             connection.write(zplData.getBytes());
 
             // Close the connection to release resources.
             connection.close();
 
         } catch (ConnectionException e) {
             // Handle communications error here.
             e.printStackTrace();
         } finally {
             connection.close();
         }
     }
 
     private void printConfigLabelUsingDnsName(String theUniqueId) throws ConnectionException {
         Connection connection = new RemoteConnection(theUniqueId);
         try {
             connection.open();
             ZebraPrinter p = ZebraPrinterFactory.getInstance(connection);
             p.printConfigurationLabel();
             connection.close();
         } catch (ConnectionException e) {
             e.printStackTrace();
         } catch (ZebraPrinterLanguageUnknownException e) {
             e.printStackTrace();
         } finally {
             connection.close();
         }
     }
 }
 

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_MAX_TIMEOUT_FOR_READ_REMOTE The default max timeout for reading from a remote connection
static int	DEFAULT_TIME_TO_WAIT_FOR_MORE_DATA_REMOTE The default max time to wait for more data for a remote connection
static int	DEFAULT_ZEBRA_WEBSERVICES_RMI_PORT The default Zebra Web services RMI Port (11995).

Constructor Summary

Constructors

Constructor and Description
RemoteConnection(String uniqueId) Initializes a new instance of the RemoteConnection class using the default Zebra Web services port (11995). This constructor will use the default timeouts for Connection.read().
RemoteConnection(String uniqueId, int rmiServerPort) Initializes a new instance of the RemoteConnection class using the specified rmiServerPort.
RemoteConnection(String uniqueId, int rmiServerPort, int maxTimeoutForRead, int timeToWaitForMoreData) Initializes a new instance of the RemoteConnection class using the specified rmiServerPort.

Method Summary

Methods

Modifier and Type	Method and Description
int	bytesAvailable() Returns an estimate of the number of bytes that can be read from this connection without blocking.
void	close() Close has no effect on a remote connection.
ConnectionReestablisher	getConnectionReestablisher(long thresholdTime) Returns a ConnectionReestablisher which allows for easy recreation of a connection which may have been closed.
int	getRmiServerPort() Returns the RMI server port.
String	getSimpleConnectionName() Return the remote connection unique id as the description.
String	getUniqueId() Returns the unique ID of the device.
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.
byte[]	read(int maxBytesToRead) Reads maxBytesToRead of the available data from the connection.
int	readChar() Reads the next byte of data from the connection, similar to a Java InputStream.
void	registerForAlerts(java.util.HashSet<AlertCondition> alertsConditionsToMonitor, AlertMonitorI monitorCallback) Register for alerts on the RemoteConnection which are being received by the Zebra Servlet Instance.
String	toString() See the classes which implement this method for the format of the description string.
void	unregisterForAlerts(java.util.HashSet<AlertCondition> alertsConditionsToMonitor, AlertMonitorI monitorCallback) Un-Register an AlertMonitor from a RemoteConnection.
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.

Methods inherited from class com.zebra.sdk.comm.ConnectionA

addWriteLogStream, getManufacturer, getMaxDataToWrite, getMaxTimeoutForRead, getTimeToWaitForMoreData, read, read, sendAndWaitForResponse, sendAndWaitForResponse, sendAndWaitForValidResponse, sendAndWaitForValidResponse, setMaxDataToWrite, setMaxTimeoutForRead, setReadTimeout, setTimeToWaitForMoreData, waitForData, write

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DEFAULT_ZEBRA_WEBSERVICES_RMI_PORT

public static final int DEFAULT_ZEBRA_WEBSERVICES_RMI_PORT

The default Zebra Web services RMI Port (11995).

See Also:

Constant Field Values

DEFAULT_MAX_TIMEOUT_FOR_READ_REMOTE

public static final int DEFAULT_MAX_TIMEOUT_FOR_READ_REMOTE

The default max timeout for reading from a remote connection

See Also:

Constant Field Values

DEFAULT_TIME_TO_WAIT_FOR_MORE_DATA_REMOTE

public static final int DEFAULT_TIME_TO_WAIT_FOR_MORE_DATA_REMOTE

The default max time to wait for more data for a remote connection

See Also:

Constant Field Values

Constructor Detail

RemoteConnection

public RemoteConnection(String uniqueId)

Initializes a new instance of the RemoteConnection class using the default Zebra Web services port (11995).
This constructor will use the default timeouts for Connection.read(). The default timeout is a maximum of 5 seconds for any data to be received. If no more data is available after 1 second the read operation is assumed to be complete.
To specify timeouts other than the defaults, use:
RemoteConnection(String, int, int, int)

Parameters:

uniqueId - the UUID of the device.

See Also:

RemoteConnection(String, int) to specify a non default RMI port.

RemoteConnection

public RemoteConnection(String uniqueId,
                int rmiServerPort)

Initializes a new instance of the RemoteConnection class using the specified rmiServerPort. This constructor will use the default timeouts for Connection.read(). The default timeout is a maximum of 5 seconds for any data to be received. If no more data is available after 1 second the read operation is assumed to be complete.
To specify timeouts other than the defaults, use:
RemoteConnection(String, int, int, int)

Parameters:

uniqueId - the UUID of the device.

rmiServerPort - the port the RMI server is running on.

RemoteConnection

public RemoteConnection(String uniqueId,
                int rmiServerPort,
                int maxTimeoutForRead,
                int timeToWaitForMoreData)

Initializes a new instance of the RemoteConnection class using the specified rmiServerPort. This constructor will use the specified timeouts for Connection.read(). The timeout is a maximum of maxTimeoutForRead milliseconds for any data to be received. If no more data is available after timeToWaitForMoreData milliseconds the read operation is assumed to be complete.

Parameters:

uniqueId - the UUID of the device.

rmiServerPort - the port the RMI server is running on.

maxTimeoutForRead - the maximum time, in milliseconds, to wait for any data to be received.

timeToWaitForMoreData - the maximum time, in milliseconds, to wait in-between reads after the initial read.

Method Detail

open

public void open()
          throws ConnectionException

Description copied from interface: Connection

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 Connection.close() to free up system resources.

Specified by:

open in interface Connection

Overrides:

open in class ConnectionA

Throws:

ConnectionException - if the connection cannot be established.

See Also:

Connection.open()

close

public void close()
           throws ConnectionException

Close has no effect on a remote connection. The connection is maintained by the printer.

Specified by:

close in interface Connection

Overrides:

close in class ConnectionA

Throws:

ConnectionException - cannot be thrown for a remote connection.

See Also:

Connection.close()

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

Overrides:

write in class ConnectionA

Parameters:

data - the data.

Throws:

ConnectionException - if an I/O error occurs.

See Also:

Connection.write(byte[])

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

Overrides:

write in class ConnectionA

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:

Connection.write(byte[], int, int)

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

Overrides:

read in class ConnectionA

Returns:

the bytes read from the connection.

Throws:

ConnectionException - if an I/O error occurs.

See Also:

Connection.read()

read

public byte[] read(int maxBytesToRead)
            throws ConnectionException

Description copied from class: ConnectionA

Reads maxBytesToRead of the available data from the connection. This call is non-blocking.

Overrides:

read in class ConnectionA

Parameters:

maxBytesToRead - number of bytes to read

Returns:

the bytes read from the connection.

Throws:

ConnectionException - if an I/O error occurs.

See Also:

ConnectionA.read(int)

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

Overrides:

readChar in class ConnectionA

Returns:

the next byte from the connection

Throws:

ConnectionException - if an I/O error occurs.

See Also:

ConnectionA.readChar()

isConnected

public boolean isConnected()

Description copied from interface: Connection

Returns true if the connection is open.

Specified by:

isConnected in interface Connection

Overrides:

isConnected in class ConnectionA

Returns:

true if this connection is open.

See Also:

Connection.isConnected()

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

Overrides:

bytesAvailable in class ConnectionA

Returns:

estimated number of bytes available.

Throws:

ConnectionException - if an I/O error occurs.

See Also:

Connection.bytesAvailable()

registerForAlerts

public void registerForAlerts(java.util.HashSet<AlertCondition> alertsConditionsToMonitor,
                     AlertMonitorI monitorCallback)
                       throws ConnectionException

Register for alerts on the RemoteConnection which are being received by the Zebra Servlet Instance.

Parameters:

alertsConditionsToMonitor - AlertConditions which will fire events for this specific listener.

monitorCallback - AlertMonitorI which provides the implementation for handling alerts.

Throws:

ConnectionException

unregisterForAlerts

public void unregisterForAlerts(java.util.HashSet<AlertCondition> alertsConditionsToMonitor,
                       AlertMonitorI monitorCallback)
                         throws ConnectionException

Un-Register an AlertMonitor from a RemoteConnection.

Parameters:

alertsConditionsToMonitor - AlertConditions which will fire events for this specific listener.

monitorCallback - AlertMonitorI which provides the implementation for handling alerts.

Throws:

ConnectionException

getUniqueId

public String getUniqueId()

Returns the unique ID of the device.

Returns:

the unique ID of the device.

getRmiServerPort

public int getRmiServerPort()

Returns the RMI server port.

Returns:

the rmiServerPort

toString

public String toString()

Description copied from interface: Connection

See the classes which implement this method for the format of the description string.

Specified by:

toString in interface Connection

Overrides:

toString in class Object

Returns:

the connection description string.

See Also:

Object.toString()

getSimpleConnectionName

public String getSimpleConnectionName()

Return the remote connection unique id as the description.

Returns:

a human-readable description of the connection.

See Also:

Connection.getSimpleConnectionName()

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

Overrides:

getConnectionReestablisher in class ConnectionA

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:

ConnectionA.getConnectionReestablisher(long thresholdTime)