This extract is used to read data from JSON files and Web Services. A JSONFile or REST connection is needed.
The extract definition uses JSONPath language, which is a standard query language for selecting nodes from a JSON document. You can find more information on JSONPath at http://goessner.net/articles/JsonPath/.
| Connection | JSONFile or REST connection. Only connections with HTTP modes GET and POST are possible for JSON extracts using REST connections. Note: during a data preview of the extract, the POST request is executed, which may provoke undesired changes on the service endpoint. |
| JsonPath loop expression | JSONPath expression that represents the root or anchor element to iterate / loop over in the JSON source file. A drop-down list offers reasonable JSONPath expressions, detected in the JSON source file, from which to select the root element. expressions can also be entered manually. |
| Export data fields / JsonPath expression | JSONPath expressions to reference the individual columns from the JSON source file, relative to the loop expression. A drop-down list offers reasonable JSONPath expressions relative to the configured JSONPath loop expression. For each column, a name and a default value can be defined. All blank (one or more white spaces) or null values will be mapped to this default value. Absolute JSONPath expressions (not relative to the JSONPath loop expression) can also be referenced in export data fields. |
JSONPath expressions will be limited to the two first array elements. JSONPath indexes start at 0, so the first two indexes offered in suggestions are 0 and 1. Further array elements, if necessary, should be entered manually.
For example, elements $feed.link[0].href and $feed.link[1].href are displayed, but $feed.link[2].href has to be entered manually.
Use caching
If caching is activated, the complete output of the extract is temporarily stored during the first call of the extract, using an internal H2 database. Subsequent calls of the extract read directly from the cache without connecting to the underlying source system of the extract. If the extract or the underlying connection contains variables, a separate cache is build for different values of these variables.
See Caching in Extracts and Transforms for more information.
Updated April 14, 2025