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[Help | API Docs | Short Course| Magercises] In this Magercise, you will add a factory interface with a single create operation to the stock IDL file, implement it, generate Java programming code from the IDL file and then compile and run the distributed stock application. This Magercise can be completed using either Sun's Java 2 ORB or Inprise's VisiBroker 3.x for Java. Notes on these products are available:
PrerequisitesSkeleton CodeTasks
First edit the IDL file. The StockObjects module in the IDL file defines the interface to a stock object. But there is currently no way for a client to create stock objects. You need to add another interface, StockFactory that has a single operation to create a stock and return a reference to the created stock. The create operation should take two string parameters: one giving the stock symbol and the other giving a description of the company.[Run IDL Compiler] At the command line, run the IDL compiler to generate Java code from the IDL file.
[Compile the generated Java code] Now compile the generated Java code using the standard Java compiler. Compile it in the generated StockObjects directory.
[Examine the generated Java files] All the files will be generated into the StockObjects directory because the IDL file defines a module StockObjects. (The purpose of each file is described in more detail in the
course notes.)
Look carefully at the file StockFactory.java - - this is the interface that you will have to implement.[Implement the stock factory] The skeleton code file we have given you, StockFactoryImpl.java has most of the implementation you will
need. To finish, add a body to the method create_stock.[Create Server Class] Now look at the file DynamicStockServer.java. This class is a java application that starts up the orb, instantiates a StockFactoryImpl instance, connects it to the ORB, and prints out a stringified reference to it.
There is nothing for you to do except look at the file. Look carefully at each line. [Create Client Class] In the file DynamicStockClient.java, you will find code to instantiate the orb, read in a stringified reference to the remote factory, and call the create_stock operation on it. Again, there is nothing for you to do except look at the file. Look carefully at each line.[Compile the program] Now compile the program using the standard Java compiler.
[Run the Server program] The server needs to run as a separate process. In DOS/Windows, you will use the start command. In UNIX, you will use the & (ampersand).
The Server outputs an IOR (or stringified reference) to a file and to the console for the Stock factory object it creates. The name of the file is passed as the first argument to the server. To run the server, use the normal java command. If you are
using VisiBroker, you can use the vbj command instead. vbj is just like java, except it sets up the CLASSPATH variables automatically.
Putting it all together:
[Run the Client program] The client reads the stringified object reference of the stock factory object created by your server. An file containing the stringified object reference is passed as the first argument to the client. The second and third arguments passed to the client is the stock symbol and company description of the stock to be created. Note the following commands are each on a single line.
[Kill the Server] Don't forget to kill the server. Where help exists, the task numbers above are linked to the step-by-step help page. This Magercise has walked you through the steps of adding dynamic distributed object creation by means of a factory object. As you probably observed, a factory object is just like any other CORBA object. Solution SourceDemonstrationWhen you start the server it should output:
The value of the IOR string will of course be different.
When you run the client with arguments Created gii for Global Industries Inc. Next MagerciseMagercisesShort CourseCopyright © 1998-1999 MageLang Institute. All Rights Reserved. | |||||||||||||||||||||||||
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