Global operators are Java operators much like the custom Java operators you can write to add functionality to StreamBase. But unlike custom Java operators, these global operators are globally available, and can be used in any application or module.
To place a global Java operator on the EventFlow canvas, drag the Java Operator icon from the Palette view. This opens the Insert Java Operator dialog that shows the global Java operators in the following table, and shows any project-specific Java operators you have added to the current project's Java Build Path. Double-click an operator's entry in the dialog, or select an operator and click .
Click the operator's name or icon in the following table to open the topic page for that operator.
| Icon | Operator | Description |
|---|---|---|
|
Drools operator | The Drools operator is a Java operator that provides a way for StreamBase applications to implement rule-based decision-making in the course of an EventFlow application. This operator embeds version 5.0 of the Drools Core rules engine, also known as JBoss Rules. You implement the operator by providing a rules file and a Java Interface file that describes the fields of interest in the operator's incoming tuple. |
|
External Process operator | The External Process operator is a Java operator that provides a way for StreamBase applications to run arbitrary operating system commands as if typed at the shell command prompt for the current operating system. This feature is especially useful in StreamBase high availability design patterns, where an an HA monitoring application in one container might need to send an sbadmin command to an application in another container or on another StreamBase Server to restart or change leadership status of the other application. |
|
Field Serializer operator | The Field Serializer operator is a Java operator that provides a way to serialize the unused fields of a large tuple into a single blob field, leaving untouched the fields that your application must process. At the end of your processing chain, after processing the fields of interest, you can deserialize the blob field to reconstruct the tuple's unused fields. This effectively compresses a large tuple as it passes through your application, for a potential throughput and performance improvement. |
|
StreamBase Admin operator | The StreamBase Admin operator is a Java operator that provides a way to directly run in Studio the equivalent of the sbadmin command-line utility without opening a shell window. Use the Admin operator to start, stop, pause, resume, and obtain status from running StreamBase applications, modules, and containers. |
|
XML Normalizer operator |
The XML Normalizer operator is a global Java operator that parses a designated field containing a string in XML format, and emits one tuple for each top-level element extracted from the XML string field. Each emitted tuple contains a user-defined set of string fields parsed from the input XML string, plus an optional field that reports any XML parsing errors. All fields in the input tuple other than the XML string field are optionally passed through unchanged to each emitted tuple, except input fields of type tuple or list, which are not supported and are emitted as null. |