File Writer Output Adapter Samples

Contents

About The Samples
Importing This Sample into StreamBase Studio
Running The Basic Sample in StreamBase Studio
Running The Advanced Sample in StreamBase Studio
Sample Location

About The Samples

There are two EventFlow modules in this sample, one basic, the other advanced.

The basic adapter sample illustrates the use of the Spotfire Streaming File Writer Adapter by taking in a tuple and writing one of its fields contents to a file.

The advanced adapter sample illustrates reading from a sample input file multiple times and writing that data back out in various compression formats.

Both samples use the system's temp folder to store the resulting output files.

Importing This Sample into StreamBase Studio

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

  • From the top-level menu, select File>Import Samples and Community Content.

  • Enter filew to narrow the list of options.

  • Select File writer output adapter from the StreamBase Standard Adapters category.

  • Click Import Now.

StreamBase Studio creates a single project containing the sample files.

Running The Basic Sample in StreamBase Studio

  1. In the Project Explorer view, open this sample's folder.

    Keep an eye on the bottom right status bar of the Studio window. Make sure any Updating, Downloading, Building, or Rebuild project messages finish before you proceed.

  2. Open the src/main/eventflow/packageName folder.

  3. Double-click to open the FileWriterBasic.sbapp module. Make sure the module is the currently active tab in the EventFlow Editor.

  4. Click the Run button. This opens the SB Test/Debug perspective and starts the module.

  5. Wait for the Waiting for fragment to initialize message to clear.

  6. In the Manual Input view, switch the Stream to Data, then enter a string value such as test, and then click Send Data to send a data tuple to be written to the file. Repeat for as many lines as you wish.

  7. In the Output Streams view, observe tuples emitted on the Status output streams indicating actions performed to the file.

  8. In the Manual Input view, switch the Stream to Control, then enter Close into the Command field, and then click Send Data to send a control tuple which will close the current file for writing.

  9. Press F9 or click the Terminate EventFlow Fragment button.

  10. This demo creates a file named SampleOut.txt containing the lines of data you submitted. The file is placed in the engine data directory of this sample's node directory, which is in the .nodes directory of your current Studio workspace. In a file browser outside of Studio, navigate a path like the following: 

    workspace/.nodes/nodename/application/engines/enginename/engine-data-area

    You can use the dataAreaPath property in a HOCON configuration file of type ldmengine to designate an alternate location for the engine data area. See the Data Directory sample for more information.

Running The Advanced Sample in StreamBase Studio

  1. Continuing in the same sample project, open the FileWriterAdvanced.sbapp file and click the Run button. This opens the SB Test/Debug perspective and starts the module, which is self-running.

  2. In the Output Streams view, observe tuples emitted on the *Status output streams indicating various actions performed on files.

  3. Press F9 or click the Terminate EventFlow Fragment button.

  4. This demo creates and removes several files as it runs:

    1. Sample.gz - This file is a GZip compressed file created from the SampleIn.txt file.

    2. Sample.gz2 - This file is a BZip2 compressed file created from the SampleIn.txt file.

    3. Sample.zip - This file is a Zip compressed file created from the SampleIn.txt file.

    4. SampleOut.txt - This file is a uncompressed file created from the SampleIn.txt file.

  5. The final result is SampleOut.txt in the engine data area for this sample, as described above.

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 permission problems. The default workspace location for this sample is: 

studio-workspace/sample_adapter_embedded_filewriter

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