Another helpful nugget in the JMeter plugin's project is the JSON Path Extractor element. This makes working with JSON pure bliss. It helps extract data out of a JSON response using JSONPath syntax (http://goessner.net/articles/JsonPath/index.html#e2). For complex JSON structures, using JMeter's bundled XPath Extractor can sometimes lead to heartache when trying to get at targeted elements. Where XPath Extractor fails, JSON Path Extractor shines.
Consider a JSON structure like the following:
{ "store": {
"book": [
{ "category": "reference",
"author": "Nigel Rees",
"title": "Sayings of the Century",
"price": 8.95
},
{ "category": "fiction",
"author": "Evelyn Waugh",
"title": "Sword of Honour",
"price": 12.99
},
{ "category": "fiction",
"author": "Herman Melville",
"title": "Moby Dick",
"isbn": "0-553-21311-3",
"price": 8.99
},
{ "category": "fiction",
...