CODEWITHSUNDEEP
jsonkotlinklaxon
Freewind
Freewind

Reputation: 198358

How to parse just part of JSON with Klaxon?

I'm trying to parse some JSON to kotlin objects. The JSON looks like:

{
    data: [
        { "name": "aaa", "age": 11 },
        { "name": "bbb", "age": 22 },
    ],
    otherdata : "don't need"
}

I just need to data part of the entire JSON, and parse each item to a User object:

data class User(name:String, age:Int)

But I can't find an easy way to do it.

Upvotes: 0

Views: 7038

Answers (1)

jivimberg
jivimberg

Reputation: 890

Here's one way you can achieve this

import com.beust.klaxon.Klaxon
import java.io.StringReader

val json = """
    {
        "data": [
            { "name": "aaa", "age": 11 },
            { "name": "bbb", "age": 22 },
        ],
        "otherdata" : "not needed"
    }
""".trimIndent()

data class User(val name: String, val age: Int)

fun main(args: Array<String>) {
    val klaxon = Klaxon()
    val parsed = klaxon.parseJsonObject(StringReader(json))
    val dataArray = parsed.array<Any>("data")
    val users = dataArray?.let { klaxon.parseFromJsonArray<User>(it) }
    println(users)
}

This will work as long as you can fit the whole json string in memory. Otherwise you may want to look into the streaming API: https://github.com/cbeust/klaxon#streaming-api

Upvotes: 4

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