Package com.softwareag.connectivity

Class AbstractSimpleCodec

java.lang.Object

com.softwareag.connectivity.ConnectivityPlugin

com.softwareag.connectivity.AbstractCodec

com.softwareag.connectivity.AbstractSimpleCodec

All Implemented Interfaces:

HostSide, TransportSide

public abstract class AbstractSimpleCodec
extends AbstractCodec

Base class that allows simplified implementation of codec plug-ins. Handles batches of messages and ignoring null payload messages (by default). Plug-in authors will typically extend this class, providing a valid constructor, and an implementation of the transformMessageTowardsHost(Message) and transformMessageTowardsTransport(Message) methods.

Subclasses should provide a constructor with the same signature as AbstractSimpleCodec(org.slf4j.Logger, PluginConstructorParameters.CodecConstructorParameters).

Field Summary

Fields inherited from class com.softwareag.connectivity.AbstractCodec

hostSide, transportSide

Fields inherited from class com.softwareag.connectivity.ConnectivityPlugin

chainId, config, CONNECTIVITY_API_VERSION, host, logger, pluginName

Constructor Summary

Constructors

Constructor	Description
AbstractSimpleCodec(org.slf4j.Logger logger, PluginConstructorParameters.CodecConstructorParameters params)	Constructor.

Method Summary

Modifier and Type	Method	Description
Message	handleException(java.lang.Exception ex, Message message, boolean towardsTransport)	Handle an exception thrown from transforming messages.
void	sendBatchTowardsHost(java.util.List<Message> messages)	Transform a batch of messages and pass them on to the next plug-in synchronously.
void	sendBatchTowardsTransport(java.util.List<Message> messages)	Transform a batch of messages and pass them on to the next plug-in synchronously.
abstract Message	transformMessageTowardsHost(Message message)	Transform an individual message with a non-null payload.
abstract Message	transformMessageTowardsTransport(Message message)	Transform an individual message with a non-null payload.
Message	transformNullPayloadTowardsHost(Message message)	Transform an individual message that has a null payload.
Message	transformNullPayloadTowardsTransport(Message message)	Transform an individual message that has a null payload.

Methods inherited from class com.softwareag.connectivity.AbstractCodec

hostReady, setNextTowardsHost, setNextTowardsTransport, shutdown, start, toString

Methods inherited from class com.softwareag.connectivity.ConnectivityPlugin

getStatusReporter

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractSimpleCodec

public AbstractSimpleCodec(org.slf4j.Logger logger,
                           PluginConstructorParameters.CodecConstructorParameters params)
                    throws java.lang.IllegalArgumentException,
                           java.lang.Exception

Constructor. A subclass should provide its own constructor with the same signature as this one. This base class makes the parameters passed into its constructor available as member fields or methods for use by the subclass.

Parameters:

logger - a slf4j Logger object which can be used to log to the host log file.

params - an extensible interface providing access to the configuration for this plug-in and other capabilities.

Throws:

java.lang.IllegalArgumentException - should be thrown from a plug-in's constructor if the configuration is invalid.

java.lang.Exception - can be thrown to indicate an internal error.

Since:

9.12.0.1

Method Detail

sendBatchTowardsTransport

public void sendBatchTowardsTransport(java.util.List<Message> messages)

Transform a batch of messages and pass them on to the next plug-in synchronously. For each message passed in, calls transformMessageTowardsTransport(Message) or transformNullPayloadTowardsTransport(Message) (if the payload was null). On an exception, calls handleException(Exception, Message, boolean). Any non-null results are then sent in a batch by calling the next plug-in in this thread.

sendBatchTowardsHost

public void sendBatchTowardsHost(java.util.List<Message> messages)

Transform a batch of messages and pass them on to the next plug-in synchronously. For each message passed in, calls transformMessageTowardsHost(Message) or transformNullPayloadTowardsHost(Message) (if the payload was null).On an exception, calls handleException(Exception, Message, boolean). Any non-null results are then sent in a batch by calling the next plug-in in this thread.

transformMessageTowardsHost

public abstract Message transformMessageTowardsHost(Message message)
                                             throws java.lang.Exception

Transform an individual message with a non-null payload. Decode an individual message, optionally producing a result. If this method throws then the exception will be logged and the message dropped.

Parameters:

message - - the message, guaranteed to be non-null and have a non-null payload.

Returns:

the decoded message, or null if it is to be discarded.

Throws:

java.lang.Exception

See Also:

transformNullPayloadTowardsHost(Message)

transformMessageTowardsTransport

public abstract Message transformMessageTowardsTransport(Message message)
                                                  throws java.lang.Exception

Transform an individual message with a non-null payload. Encode an individual message, optionally producing a result. If this method throws then the exception will be logged and the message dropped.

Parameters:

message - - the message, guaranteed to be non-null and have a non-null payload.

Returns:

the encoded message, or null if it is to be discarded.

Throws:

java.lang.Exception

See Also:

transformNullPayloadTowardsTransport(Message)

transformNullPayloadTowardsHost

public Message transformNullPayloadTowardsHost(Message message)
                                        throws java.lang.Exception

Transform an individual message that has a null payload.

By convention, most plug-ins silently pass through messages with null payloads without transforming them. Thus, the default implementation of this method is to just return the value passed in. If this method throws then the exception will be logged and the message dropped.

Throws:

java.lang.Exception

transformNullPayloadTowardsTransport

public Message transformNullPayloadTowardsTransport(Message message)
                                             throws java.lang.Exception

Transform an individual message that has a null payload.

By convention, most plug-ins silently pass through messages with null payloads without transforming them. Thus, the default implementation of this method is to just return the value passed in. If this method throws then the exception will be logged and the message dropped.

Throws:

java.lang.Exception

handleException

public Message handleException(java.lang.Exception ex,
                               Message message,
                               boolean towardsTransport)

Handle an exception thrown from transforming messages.

The default implementation is to log an error and return null (thus discarding this message, but not others in the same batch)

Parameters:

e - T