This sample provides Java code that illustrates the
StreamBaseClient.readTable()method, which is used to display all or a specified number of rows from a Query Table. The Java code is provided in the
ReadTableClient.java program in the
The sample contains an EventFlow application,
ReadTable.sbapp that contains the following elements:
A local Query Table named
A module reference to
ReadTableModule.sbapp, which contains a shared table named
A module reference to
ReadTableModuleWithPlaceholder.sbapp, which contains a placeholder table named
PlaceholderTablethat is mapped to
The sample demonstrates the ability to retrieve rows from any of these tables, using the following paths at runtime:
containername is optional if you run
ReadTable.sbapp in the default container named
default, but must be present for non-default container names.
You run this sample in two steps:
On startup, a CSV File Reader adapter populates all tables with the same contents, which are read from the file
InitialData.txt. (You can supplement this populated data by sending tuples to the
InsertToAllTablesinput stream.) The application then awaits further input or a client connection.
ReadTableClient.javaprogram as a Java application. This StreamBase client program connects to the
ReadTable.sbappapplication, reads values from its various table constructs, and prints its output to the console.
In StreamBase Studio, import this sample with the following steps:
From the top-level menu, click> .
readtto narrow the list of options.
Select the Read Query Table from Java clients sample from the Client Libraries category.
StreamBase Studio creates a project for this sample.
Follow these steps:
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
Rebuild projectmessages finish before you proceed.
Double-click to open the
ReadTable.sbappmodule. Make sure the module is the currently active tab in the EventFlow Editor.
Click the Run button. This opens the SB Test/Debug perspective and starts the module.
Wait for the Waiting for fragment to initialize message to clear.
Return to the SB Authoring perspective.
In the Project Explorer view, open the
src/main/java/folder tree to expose the
ReadTableClient.javafile and from the context menu, select > .
Observe the results of the Java program in the Console view.
When done, press F9 or click the Terminate EventFlow Fragment button.
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.