Example: Implementing a client-side adapter

 

The CommandTarget interface declares one method, executeCommand, which the client implements. The executeCommand method takes a TargetableCommand object as input; it also returns a TargetableCommand.

 

A client-side implementation of the executeCommand method

This example shows the implementation of the method used in the client-side adapter. This implementation does the following:

• Serializes the command it receives

• Creates an HTTP connection to the servlet

• Creates input and output streams, to handle the command as it is sent to the server and returned

• Places the command on the output stream

• Sends the command to the server

• Retrieves the returned command from the input stream

• Returns the returned command to the caller of the executeCommand method

public TargetableCommand executeCommand(TargetableCommand command) throws CommandException
{ try {
// Serialize the command byte[] array = serialize(command);
// Create a connection to the servlet
URL url = new URL ("http://" + hostName +
"/servlet/com.ibm.websphere.command.servlet.CommandServlet");
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
// Set the properties of the connection
...
// Put the serialized command on the output stream
OutputStream outputStream = httpURLConnection.getOutputStream(); outputStream.write(array);
// Create a return stream
InputStream inputStream = httpURLConnection.getInputStream();
// Send the command to the servlet httpURLConnection.connect();
ObjectInputStream objectInputStream = new ObjectInputStream(inputStream);
// Retrieve the command returned from the servlet
Object object = objectInputStream.readObject(); if (object instanceof CommandException) { throw ((CommandException) object);
}
// Pass the returned command back to the calling method return (TargetableCommand) object;
}
// Handle exceptions
....
}

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Related tasks

Use a command

 

Related Reference

Example: Running the command in the servlet
Example: Writing a command target (client-side adapter)

 

Reference topic