Map Operator Sample

About This Sample

This sample uses a Map operator to accept tuples containing fields called Stockname, Symbol, Description, Volume, and Price. For each input tuple, a tuple containing only the fields called Symbol, Stockname, and Stockcost are output. This demonstrates one use of the Map operator to reorder and drop output fields, as well as calculate new output fields.

Importing This Sample into StreamBase Studio

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

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

  • Enter sample group to narrow the list of options.

  • Select Operator sample group from the Data Constructs and Operators category.

  • Click Import Now.

StreamBase Studio creates a single project for the operator samples.

Running This Sample in StreamBase Studio

  1. In the Project Explorer view, open the sample you just loaded.

    If you see red marks on a project folder, wait a moment for the project to load its features.

    If the red marks do not resolve themselves after a minute, select the project, right-click, and select Maven>Update Project from the context menu.

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

  3. Open the Map.sbapp file and click the Run button. This opens the SB Test/Debug perspective and starts the module.

  4. In the Output Streams view, select the StockOut output stream. No output is displayed at this point, but the dequeuer is prepared to receive output. This view eventually shows the output of the application.

  5. In the Manual Input view, select the StockIn input stream.

  6. Enter the following field values:

    Field Enter this value
    Symbol GE
    Name General Electric
    Description Makes everything from light bulbs to airplane engines.
    Volume 40487000
    Price 30.29
  7. Click Send Data, and a tuple arrives in the Output Streams view. Select the new tuple and observe this data below the output stream table:

    StockName=General Electric, StockSymbol=GE, StockCost=1.22635123E9
  8. When done, press F9 or click the Terminate EventFlow Fragment button.

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.


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:


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