Sunday, March 8, 2015

Comparing JSON Strings with Jackson

Here's a quick way to compare two JSON String using Jackson. While we could always do a simple String compare, this method allows us to keep the expected JSON in a readable format, such as pretty-printed in a test resource:

import com.fasterxml.jackson.databind.ObjectMapper

class JsonAssert {

    static ObjectMapper mapper = new ObjectMapper()

    static void areEqual(String json1, String json2) {
        def tree1 = mapper.readTree json1
        def tree2 = mapper.readTree json2

        assert tree1.equals(tree2)


The above can be called from an expect: or then: block in a Spock specification.