How to test if JSON object is empty in Java

Question

The JSON object I\'m receiving looks like this:

[{\"foo1\":\"bar1\", \"foo2\":\"bar2\", \"problemkey\": \"problemvalue\"}]

What I\'m trying

Answer 1

if (jsonObj != null && jsonObj.length > 0)

To check if a nested JSON object is empty within a JSONObject:

if (!jsonObject.isNull("key") && jsonObject.getJSONObject("key").length() > 0)

Answer 2

Use the following code:

if(json.isNull()!= null){  //returns true only if json is not null

}

Answer 3

Try:

if (record.has("problemkey") && !record.isNull("problemkey")) {
    // Do something with object.
}

Answer 4

@Test
public void emptyJsonParseTest() {
    JsonNode emptyJsonNode = new ObjectMapper().createObjectNode();
    Assert.assertTrue(emptyJsonNode.asText().isEmpty());
}

Answer 5

Try /*string with {}*/ string.trim().equalsIgnoreCase("{}")), maybe there is some extra spaces or something

Answer 6

For this case, I do something like this:

var obj = {};

if(Object.keys(obj).length == 0){
        console.log("The obj is null")
}