JsonUtil.kt

class JsonUtil {

    companion object {

        fun findJson(mixedString: String): Pair<String, MutableList<String>> {
            var mixed = mixedString
            val jsons: MutableList<String> = ArrayList()
            var first = mixed.indexOf('{')
            while (first > -1) {
                var last = mixed.lastIndexOf('}')
                while (last > -1 && first > -1 && last > first) {
                    val bracesSubstring = mixed.substring(first, last + 1)
                    if (!bracesSubstring.isValidJson()) {
                        last--
                        continue
                    }
                    if (first + 1 != last)
                        jsons.add(bracesSubstring)
                    mixed = mixed.removeRange(first, last + 1)
                    //Start again
                    first = mixed.indexOf('{')
                    last = mixed.lastIndexOf('}')
                }
                if (first <= -1 || last <= -1) break else {
                    first = mixed.indexOf('{', first + 1)
                }
            }
            return Pair(mixed, jsons)
        }

        fun String.isValidJson(): Boolean {
            return try {
                Gson().fromJson(this, JsonObject::class.java) != null
            } catch (exc: Exception) {
                false
            }
        }
    }
}