Package com.automation_pros.odva.cip.types

Class Capsule

java.lang.Object

com.automation_pros.odva.cip.types.Capsule

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable

public abstract class Capsule
extends java.lang.Object
implements java.io.Externalizable

Streaming protocols need to mark message boundaries and indicate message type and total length. In fully generic form, such a message has a header from which the trailing boundary can be computed or inferred. Instances are expected to serialize themselves to their standard bytestream and deserialize themselves accordingly.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
Capsule()	No-args constructor for deserialization.

Method Summary

Modifier and Type	Method	Description
Capsule	decode(EndianDataInput in)	Construct a complete instance from a suitable stream data source.
abstract Capsule	decodeHeader(EndianDataInput in)	Initialize an instance from a suitable stream data source.
abstract Capsule	decodeVariant(EndianDataInput in)	Populate an instance's payload from a suitable stream data source.
Capsule	encode(EndianDataOutput out)	Export an instance's header and payload to wire format in a suitable stream data sink.
abstract Capsule	encodeHeader(EndianDataOutput out)	Export an instance's header to wire format in a suitable stream data sink.
abstract Capsule	encodeVariant(EndianDataOutput out)	Export an instance's payload to wire format in a suitable stream data sink.
abstract int	headerLength()	Subclasses must report a constant header length, which must include enough information to compute the length of the balance of the encoded message.
void	readExternal(java.io.ObjectInput in)
abstract int	variantLength()	After an instance's decodeHeader() method has been called, or an instance is constructed by other means, the payload length must be known.
void	writeExternal(java.io.ObjectOutput out)

Methods inherited from class java.lang.Object

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

Constructor Detail

Capsule

public Capsule()

No-args constructor for deserialization.

Method Detail

headerLength

public abstract int headerLength()

Subclasses must report a constant header length, which must include enough information to compute the length of the balance of the encoded message.

Returns:

Number of bytes in the specific type's message header.

variantLength

public abstract int variantLength()

After an instance's decodeHeader() method has been called, or an instance is constructed by other means, the payload length must be known.

Returns:

Number of bytes in the specific instance's variant payload.

decodeHeader

public abstract Capsule decodeHeader(EndianDataInput in)
                              throws java.io.IOException

Initialize an instance from a suitable stream data source.

Parameters:

in - A stream that offers big endian and little endian primitive access.

Returns:

A chainable reference to the instance.

Throws:

java.io.IOException

decodeVariant

public abstract Capsule decodeVariant(EndianDataInput in)
                               throws java.io.IOException

Populate an instance's payload from a suitable stream data source.

Parameters:

in - A stream that offers big endian and little endian primitive access.

Returns:

A chainable reference to the instance.

Throws:

java.io.IOException

decode

public Capsule decode(EndianDataInput in)
               throws java.io.IOException

Construct a complete instance from a suitable stream data source.

Parameters:

in - A stream that offers big endian and little endian primitive access.

Returns:

A chainable reference to the instance.

Throws:

java.io.IOException

encodeHeader

public abstract Capsule encodeHeader(EndianDataOutput out)
                              throws java.io.IOException

Export an instance's header to wire format in a suitable stream data sink. This method must be followed by a call to encodePayload() to have a valid message on the wire.

Parameters:

out - A stream that offers big endian and little endian primitive access.

Returns:

A chainable reference to the instance.

Throws:

java.io.IOException

encodeVariant

public abstract Capsule encodeVariant(EndianDataOutput out)
                               throws java.io.IOException

Export an instance's payload to wire format in a suitable stream data sink. Should immediately follow encodeHeader().

Parameters:

out - A stream that offers big endian and little endian primitive access.

Returns:

A chainable reference to the instance.

Throws:

java.io.IOException

encode

public Capsule encode(EndianDataOutput out)
               throws java.io.IOException

Export an instance's header and payload to wire format in a suitable stream data sink.

Parameters:

out - A stream that offers big endian and little endian primitive access.

Returns:

A chainable reference to the instance.

Throws:

java.io.IOException

writeExternal

public void writeExternal(java.io.ObjectOutput out)
                   throws java.io.IOException

Specified by:

writeExternal in interface java.io.Externalizable

Throws:

java.io.IOException

readExternal

public void readExternal(java.io.ObjectInput in)
                  throws java.lang.ClassNotFoundException,
                         java.io.IOException

Specified by:

readExternal in interface java.io.Externalizable

Throws:

java.lang.ClassNotFoundException

java.io.IOException