POP-Java plugin¶
The POP-Java system can be augmented by its users. If the programmer feels the need of a new network protocol or a new encoding protocol, he can create a POP-Java plugin and add it to the system easily. This chapter aims to present the combox and the buffer plugin systems.
Combox plugin¶
The Combox is the component responsible for the network communication between an application and a parallel object or between two parallel objects. In the current version of POP-Java, only the protocol socket is implemented. If the programmer needs another protocol, he can create his own Combox.
To create a new protocol for POP-Java, the programmer needs to create three different classes : a combox, a combox server and a combox factory.
The combox must inherit from the super class ComboxPlugin located in the
package popjava.combox in the POP-Java library. The
Figure 1 shows the ComboxPlugin class signature.
Figure 1: ComboxPlugin class signature
The combox server must inherit from the super class ComboxServer located in the package popjava.combox in the POP-Java library. The Figure 2 shows the ComboxServer class signature.
Figure 2: ComboxServer class signature
The combox factory must inherit from the super class ComboxFactory located in
the package popjava.combox in the POP-Java library. The
Figure 3 shows the ComboxFactory class signature.
Figure 3: ComboxFactory signature
Once all the classes are implemented, the programmer needs to compile them as
standard Java code and create a JAR file. This JAR file can be added in the
system by editing the file pop_combox.xml located in the directory
POPJAVA_LOCATION/plugin. The XML code below is the current XML file with
the socket protocol.
<ComboxFactoryList>
<Package JarFile="popjava.combox.jar">
<ComboxFactory>popjava.combox.ComboxSocketFactory</ComboxFactory>
</Package>
</ComboxFactoryList>
Buffer plugin¶
The buffer is the component in charge of the data encoding. In the current implementation of POP-Java, two buffers are available. One is using the RAW encoding and the other is using the XDR encoding. If the programmer needs a special encoding protocol, he can also create his own and add it to the POP-Java system as a plugin.
To implement a new encoding protocol, the programmer needs to create two classes. A buffer and a buffer factory.
The buffer must inherit from the class BufferPlugin located in the
package popjava.buffer in the POP-Java library. The
Figure 4 shows the BufferPlugin class signature.
Figure 4: BufferPlugin class signature
The buffer factory must inherit from the super class BufferFactory located
in the package popjava.buffer in the POP-Java library. The
Figure 5 shows the BufferFactory class signature.
Figure 5: BufferFactory class signature