Bi-Directional JSON Socket Input/Output Adapter Samples

About The Samples

The Bi-Directional JSON Socket input and output adapters receive and send data over a socket connection in the JSON format. The sample shows how adapter pairs work together when linked. The adapter wraps the functionality of the JSONDataTransformer, which converts tuples into escaped JSON strings and delimits tuples with a separator character, before sending the data over a socket.

The server section and client section both have a set of linked adapters to input and output on the same socket. The client and server continually exchange messages. At each exchange, the client increments an integer value (testint, initialized in the Defaults Map operator) until a finishing value is reached. When you run this sample, you can see values for the ReadDataClient and ReadDataServer incrementing and alternating.

Running The HTTP Sample in StreamBase Studio

In the Package Explorer, double-click to open the JSONHttp.sbapp to open the example. Make sure the application is the currently active tab in the EventFlow Editor.
Click the Run button. This opens the SB Test/Debug perspective and starts the application.
For the example, in the Manual Input view select the ControlClient Stream, then enter CONNECT into the command field, then click Send Data to send the tuple.
In the Application Output view, observe tuples emitted on the Data output stream.
Select any tuple emitted from either stream and inspect tuple data fields in the Variables view below the output streams to analyze and understand their structure.
When done, press F9 or click the Stop Running Application button.

Running The Basic Socket Sample in StreamBase Studio

In the Package Explorer, double-click to open the JSONBiDirectionalSocket.sbapp to open the example. Make sure the application is the currently active tab in the EventFlow Editor.
Click the Run button. This opens the SB Test/Debug perspective and starts the application.
For the example, in the Manual Input view select the ControlClient Stream, then enter CONNECT into the command field, then click Send Data to send the tuple.
In the Application Output view, observe tuples emitted on the ReadDataServer and ReadDataClient output streams.
Select any tuple emitted from either stream and inspect tuple data fields in the Variables view below the output streams to analyze and understand their structure.
When done, press F9 or click the Stop Running Application button.

Running The Basic Socket Sample in Terminal Windows

This section describes how to run this sample in UNIX terminal windows or Windows command prompt windows. Running this sample in terminal windows does not provide the best illustration of the Web Reader adapter, because tuples emitted on its primary output port are not designed for human readability. Nevertheless, if you only have terminal access to a UNIX server running StreamBase, follow the steps in this section.

On Windows, be sure to use the StreamBase Command Prompt from the Start menu as described in the Test/Debug Guide, not the default command prompt.

Open three terminal windows on UNIX, or three StreamBase Command Prompts on Windows. In each window, navigate to your workspace copy of the sample, as described above.
In window 1, type:
```
sbd JSONBiDirectionalSocket.sbapp
```
In window 2, type:
```
sbc dequeue ReadDataClient
```
This window will display tuples dequeued from the adapter's primary output port.
In window 3, type:
```
sbc enqueue ControlClient
```
In window 3 type:
```
CONNECT,null,null,null
```
and press Enter.
Observe in window 2 that tuples are emitted from the ReadDataClient stream. The tuples contain an integer field which is incremented each time it goes to the server and comes back to the client.
In window 3, type Ctrl+C, then the following command to terminate the server and dequeuer:
```
sbadmin shutdown
```

Importing This Sample into StreamBase Studio

In StreamBase Studio, import this sample with the following steps:

From the top menu, select File → Load StreamBase Sample.
Select Bi-Directional JSON Socket Input/Output Adapter from the StreamBase Standard Adapters category.
Click OK.

StreamBase Studio creates a single project containing the sample files.

Sample Location

When you load the sample into StreamBase Studio, Studio copies the sample project's files to your Studio workspace, which is normally part of your home directory, with full access rights.

Important

Load this sample in StreamBase Studio, and thereafter use the Studio workspace copy of the sample to run and test it, even when running from the command prompt.

Using the workspace copy of the sample avoids the permission problems that can occur when trying to work with the initially installed location of the sample. The default workspace location for this sample is:

studio-workspace/sample_adapter_embedded_bi-directional-json-socket

See Default Installation Directories for the location of studio-workspace on your system.

In the default TIBCO StreamBase installation, this sample's files are initially installed in:

streambase-install-dir/sample/adapter/embedded/bi-directional-json-socket

See Default Installation Directories for the default location of studio-workspace on your system.