StringCase.sbapp sample application uses a Java
operator to change the case of strings. This is then used to implement
case-insensitive query table lookups.
This topic describes the Java operator sample, which includes a StreamBase
application and a Java class that extends
For details about how StreamBase used the API to extend
com.streambase.sb.operator.*, see Using the StreamBase Java
Operator Wizard in the API Guide. For information
about importing a JAR that contains a Java Operator in StreamBase Studio, and then
Operator class from that JAR, see
Using Java Operators in
the Authoring Guide.
For details about using custom icons with your Java operators, see the Java Client
library documentation for
The Java code in this sample is delivered only in source code form. To build the code, you must load the sample into StreamBase Studio, which automatically builds the Java code, or use javac on the command line.
In StreamBase Studio, import this sample with the following steps:
From the top-level menu, select> .
javaoto narrow the list of options.
Select Custom Java operator from the Extending StreamBase category.
StreamBase Studio creates a project for the sample.
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> from the context menu.
src/main/javafolder in the project folder. Under the
StringCase.java, which extends
StringCase.sbappEventFlow module file.
operator in the canvas to open its Properties view. In the Parameters tab, notice that the string conversion type is set by default to
Lowercase. Change this setting to
Uppercase. Do the same for the
StringCase.sbappis the currently active tab in the EventFlow Editor, then click the button. This starts the fragment and Studio switches to the SB Test/Debug perspective.
Select the Manual Input view. Selectfrom the Input Stream list.
ibm, and in the
150, and click .
In the Output Streams view, notice that in OutputStream1, after the write to the Query Table, the symbol string is
48, and click .
In the Manual Input view, select
PriceQueryfrom the Input Stream list.
ibm, and click . The price,
150, is displayed in the Output Streams view.
oRcLin mixed case, and click . The price,
48, is displayed in the Output Streams view. Notice that the table lookup was successful, because the string is stored as uppercase, despite the mixed-case initial input.
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.