Selecting a subset of JSON properties and values using JSONPath

问题

Given a JSON like:

{
  "a":1,
  "b":2,
  "c":3,
  "d":4,
  "e":5
}

How can I select out b, d and e to get the following JSON?

{
  "b":2,
  "d":4,
  "e":5
}

I want a JSON object and NOT only 2, 4 and 5 values?

This is what I'm trying with and failing:

$.[b,d,e]

回答1:

JSONPath is not suitable for what you are trying to achieve: JSONPath is designed to select values and not key-value pairs. What you want could be achieved with Jackson or any JSON parser for Java.

If you want to go for Jackson here's the code that will do the trick:

String json = "{\"a\":1,\"b\":2,\"c\":3,\"d\":4,\"e\":5}";

ObjectMapper mapper = new ObjectMapper();
JsonNode tree = mapper.readTree(json);

ObjectNode node = mapper.createObjectNode();
node.set("b", tree.get("b"));
node.set("d", tree.get("d"));
node.set("e", tree.get("e"));

String result = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(node);

回答2:

Your json path is correct, while json it self is not. It should be:

{
"a":1,
"b":2,
"c":3,
"d":4,
"e":5
}

BTW there is good online testing resources for these purposes: http://jsonpath.com/

回答3:

Elements must be in single quotes.

$.['b','d','e']

Works fine for JsonPath from com.jayway.jsonpath:json-path:2.4.0

回答4:

You need to modify your JSON to (as said by Andremoniy)

{
"a":1,
"b":2,
"c":3,
"d":4,
"e":5
}

and to select b,d,e use this

$.b,d,e

来源：https://stackoverflow.com/questions/40017445/selecting-a-subset-of-json-properties-and-values-using-jsonpath