Description:

Evaluates one or more JsonPath expressions against the content of a FlowFile. The results of those expressions are assigned to FlowFile Attributes or are written to the content of the FlowFile itself, depending on configuration of the Processor. JsonPaths are entered by adding user-defined properties; the name of the property maps to the Attribute Name into which the result will be placed (if the Destination is flowfile-attribute; otherwise, the property name is ignored). The value of the property must be a valid JsonPath expression. If the JsonPath evaluates to a JSON array or JSON object and the Return Type is set to 'scalar' the FlowFile will be unmodified and will be routed to failure. A Return Type of JSON can return scalar values if the provided JsonPath evaluates to the specified value and will be routed as a match. If Destination is 'flowfile-content' and the JsonPath does not evaluate to a defined path, the FlowFile will be routed to 'unmatched' without having its contents modified. If Destination is flowfile-attribute and the expression matches nothing, attributes will be created with empty strings as the value, and the FlowFile will always be routed to 'matched.'

Note: The underlying JsonPath library loads the entirety of the streamed content into and performs result evaluations in memory. Accordingly, it is important to consider the anticipated profile of content being evaluated by this processor and the hardware supporting it especially when working against large JSON documents.

Properties:

In the list below, the names of required properties appear in bold. Any other properties (not in bold) are considered optional. If a property has a default value, it is indicated. If a property supports the use of the NiFi Expression Language (or simply, "expression language"), that is also indicated.

Modifies Attributes:

This processor adds user-defined attributes if the <Destination> property is set to flowfile-attribute.

• Destination
  • Indicates whether the results of the JsonPath evaluation are written to the FlowFile content or a FlowFile attribute; if using attribute, the attribute's name must be specified in the value of the Attribute Name property.
  • Valid values are:
    • flowfile-content
    • flowfile-attribute
  • Default value: flowfile-content
  • Supports expression language: false
• Return Type
  • Indicates the desired return type of the JsonPath expressions. Selecting 'auto-detect' will set the return type to 'json' for a Destination of 'flowfile-content', and 'scalar' for a Destination of 'flowfile-attribute'.")
  • Valid values are:
    • auto-detect
    • json
    • scalar
  • Default value: auto-detect
  • Supports expression language: false
• user-defined properties
  • The name of the attribute to put the JsonPath result into if flowfile-attribute is used as the value for the Destination property; if using flowfile-content as the value for the Destination property, this value is ignored.
  • Supports expression language: false

Relationships:

• failure
  • If the JsonPath cannot be evaluated against the content of the FlowFile, then the FlowFile follows this relationship. For example, if the FlowFile does not contain valid JSON.
• matched
  • If the JsonPath is successfully evaluated and the FlowFile is modified as a result, then the FlowFile follows this relationship.
• unmatched
  • If the JsonPath does not match the content of the FlowFile, then the FlowFile follows this relationship.