Expression Language
The StreamSets expression language enables you to create expressions that evaluate or modify data. The StreamSets expression language is based on the JSP 2.0 expression language.
Use the expression language to configure expressions and conditions in processors, such as the Expression Evaluator or Stream Selector. Some destination properties also allow the expression language, such as the directory template for the Hadoop FS destination.
You can use the expression language to define any stage or pipeline property that represents a numeric or string value. You can also use field path expressions to select the fields to use in some processors.
Use expression completion to determine where you can use an expression and the expression elements that you can use in that location.
- Constants
- Datetime variables
- Field names
- Functions
- Literals
- Operators
- Runtime parameters
- Runtime properties
- Runtime resources
For more information about using expressions in pipelines, see Expression Configuration.