JsonTreeReader

Description

Parses JSON into individual Record objects. While the reader expects each record to be well-formed JSON, the content of a FlowFile may consist of many records, each as a well-formed JSON array or JSON object with optional whitespace between them, such as the common ‘JSON-per-line’ format. If an array is encountered, each element in that array will be treated as a separate record. If the schema that is configured contains a field that is not present in the JSON, a null value will be used. If the JSON contains a field that is not present in the schema, that field will be skipped. See the Usage of the Controller Service for more information and examples.

Tags

json, parser, reader, record, tree

Properties

In the list below required Properties are shown with an asterisk (*). Other properties are considered optional. The table also indicates any default values, and whether a property supports the NiFi Expression Language.

Display Name

API Name

Default Value

Allowable Values

Description

Allow Comments *

Allow Comments

false

  • true

  • false

Whether to allow comments when parsing the JSON document

Date Format

Date Format

Specifies the format to use when reading/writing Date fields. If not specified, Date fields will be assumed to be number of milliseconds since epoch (Midnight, Jan 1, 1970 GMT). If specified, the value must match the Java java.time.format.DateTimeFormatter format (for example, MM/dd/yyyy for a two-digit month, followed by a two-digit day, followed by a four-digit year, all separated by ‘/’ characters, as in 01/01/2017).

Max String Length *

Max String Length

20 MB

The maximum allowed length of a string value when parsing the JSON document

Time Format

Time Format

Specifies the format to use when reading/writing Time fields. If not specified, Time fields will be assumed to be number of milliseconds since epoch (Midnight, Jan 1, 1970 GMT). If specified, the value must match the Java java.time.format.DateTimeFormatter format (for example, HH:mm:ss for a two-digit hour in 24-hour format, followed by a two-digit minute, followed by a two-digit second, all separated by ‘:’ characters, as in 18:04:15).

Timestamp Format

Timestamp Format

Specifies the format to use when reading/writing Timestamp fields. If not specified, Timestamp fields will be assumed to be number of milliseconds since epoch (Midnight, Jan 1, 1970 GMT). If specified, the value must match the Java java.time.format.DateTimeFormatter format (for example, MM/dd/yyyy HH:mm:ss for a two-digit month, followed by a two-digit day, followed by a four-digit year, all separated by ‘/’ characters; and then followed by a two-digit hour in 24-hour format, followed by a two-digit minute, followed by a two-digit second, all separated by ‘:’ characters, as in 01/01/2017 18:04:15).

Schema Access Strategy *

schema-access-strategy

infer-schema

  • Infer Schema

  • Use ‘Schema Name’ Property

  • Use ‘Schema Text’ Property

  • Schema Reference Reader

Specifies how to obtain the schema that is to be used for interpreting the data.

Schema Application Strategy *

schema-application-strategy

SELECTED_PART

  • Whole JSON

  • Selected Part

Specifies whether the schema is defined for the whole JSON or for the selected part starting from “Starting Field Name”.

Schema Branch

schema-branch

Specifies the name of the branch to use when looking up the schema in the Schema Registry property. If the chosen Schema Registry does not support branching, this value will be ignored.

Schema Inference Cache

schema-inference-cache

Specifies a Schema Cache to use when inferring the schema. If not populated, the schema will be inferred each time. However, if a cache is specified, the cache will first be consulted and if the applicable schema can be found, it will be used instead of inferring the schema.

Schema Name

schema-name

${schema.name}

Specifies the name of the schema to lookup in the Schema Registry property

Schema Reference Reader *

schema-reference-reader

Service implementation responsible for reading FlowFile attributes or content to determine the Schema Reference Identifier

Schema Registry

schema-registry

Specifies the Controller Service to use for the Schema Registry

Schema Text

schema-text

${avro.schema}

The text of an Avro-formatted Schema

Schema Version

schema-version

Specifies the version of the schema to lookup in the Schema Registry. If not specified then the latest version of the schema will be retrieved.

Starting Field Name

starting-field-name

Skips forward to the given nested JSON field (array or object) to begin processing.

Starting Field Strategy *

starting-field-strategy

ROOT_NODE

  • Root Node

  • Nested Field

Start processing from the root node or from a specified nested node.

State management

This component does not store state.

Restricted

This component is not restricted.

System Resource Considerations

This component does not specify system resource considerations.

Language: English