Demo how to use Moshi with Kotlin

MoshiKotlinExample.kt

import com.squareup.moshi.Json
import com.squareup.moshi.KotlinJsonAdapterFactory
import com.squareup.moshi.Moshi
import com.squareup.moshi.Rfc3339DateJsonAdapter
import java.util.Date

val json = """
{
  "url": "https://api.github.com/repos/square/okio/issues/156",
  "id": 91393390,
  "number": 156,
  "title": "ByteString.utf8CharSequence()",
  "labels": [
    {
      "url": "https://api.github.com/repos/square/okio/labels/enhancement",
      "id": 86454697,
      "name": "enhancement",
      "color": "84b6eb"
    }
  ],
  "milestone": {
    "url": "https://api.github.com/repos/square/okio/milestones/2",
    "id": 992290,
    "title": "Icebox",
    "creator": {
      "url": "https://api.github.com/users/swankjesse",
      "login": "swankjesse"
    },
    "open_issues": 12,
    "closed_issues": 1,
    "created_at": "2015-02-24T00:59:14.000Z"
  },
  "state": "open",
  "created_at": "2015-06-27T00:49:40.000Z",
  "body": "Would be interesting to return a `CharSequence` that's backed by the same `ByteArray`.\n"
}
"""

data class Issue(
    val url: String,
    val id: Long,
    val number: Long,
    val title: String,
    val labels: List<Label> = listOf<Label>(),
    val milestone: Milestone?,
    val assignees: List<User> = listOf<User>(),
    val state: State,
    val comments: Long = 0L,
    @Json(name = "created_at") val createdAt: Date,
    @Json(name = "closed_at") val closedAt: Date?,
    val body: String = ""
)

enum class State {
  @Json(name = "open") OPEN,
  @Json(name = "closed") CLOSED
}

data class Label(
    val url: String,
    val id: Long,
    val name: String,
    val color: String = "46DF1B"
)

data class Milestone(
    val url: String,
    val id: Long,
    val title: String,
    val creator: User,
    @Json(name = "open_issues") val openCount: Long = 0L,
    @Json(name = "closed_issues") val closedCount: Long = 0L,
    @Json(name = "created_at") val createdAt: Date,
    @Json(name = "due_on") val dueOn: Date?
)

data class User(val url: String, val login: String)

fun main(args: Array<String>) {
  val moshi = Moshi.Builder()
      .add(KotlinJsonAdapterFactory)
      .add(Date::class.java, Rfc3339DateJsonAdapter().nullSafe())
      .build()

  val issueAdapter = moshi.adapter(Issue::class.java)

  val issue = issueAdapter.fromJson(json)

  println(issue)
}

Can you give same example of progaurd files ?

why using @JSON annotation only with few keys?

why using @JSON annotation only with few keys?

well kotlin properties names must match with the property(or name of key in json). this can lead to unwanted or against coding style, like we use "camelCase" for properties in kotlin and here some json keys that has names like "open_issues" (contains underscore), so we have to give our property a name as the name of key in json. To avoid doing so we use @JSON annotation to use desired name for our properties

its is similar to serializable naming in data model for retrofit with latest some extra features i think