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JakeWharton/Json.kt Secret

Created April 11, 2019 04:08
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  1. JakeWharton created this gist Apr 11, 2019.
    138 changes: 138 additions & 0 deletions Json.kt
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,138 @@
    import java.io.StringReader
    import java.time.OffsetDateTime
    import android.util.JsonReader
    import android.util.JsonToken

    fun main() {
    println(TweetParser.fromJson(JsonReader(StringReader(""))))
    println(UserParser.fromJson(JsonReader(StringReader(""))))
    }

    data class User(
    val id: String,
    val username: String,
    val displayName: String,
    val email: String,
    val created: OffsetDateTime,
    val isPublic: Boolean
    )

    data class Tweet(
    val id: String,
    val userId: String,
    val content: String,
    val created: OffsetDateTime
    )

    object UserParser {
    fun fromJson(reader: JsonReader): User {
    var id: String? = null
    var username: String? = null
    var displayName: String? = null
    var email: String? = null
    var created: OffsetDateTime? = null
    var isPublic: Boolean? = null

    reader.beginObject()
    while (reader.peek() != JsonToken.END_OBJECT) {
    when (reader.nextName()) {
    "id" -> id = reader.nextString() ?:
    throw IllegalStateException(
    StringBuilder("Non-null value '").append("id")
    .append("' was null at ").append(reader).toString())
    "username" -> username = reader.nextString() ?:
    throw IllegalStateException(
    StringBuilder("Non-null value '").append("username")
    .append("' was null at ").append(reader).toString())
    "displayName" -> displayName = reader.nextString() ?:
    throw IllegalStateException(
    StringBuilder("Non-null value '").append("displayName")
    .append("' was null at ").append(reader).toString())
    "email" -> email = reader.nextString() ?:
    throw IllegalStateException(
    StringBuilder("Non-null value '").append("email")
    .append("' was null at ").append(reader).toString())
    "created" -> created = reader.nextString()?.let(OffsetDateTime::parse) ?:
    throw IllegalStateException(
    StringBuilder("Non-null value '").append("created")
    .append("' was null at ").append(reader).toString())
    "isPublic" -> isPublic = reader.nextString()?.toBoolean() ?:
    throw IllegalStateException(
    StringBuilder("Non-null value '").append("isPublic")
    .append("' was null at ").append(reader).toString())
    else -> reader.skipValue()
    }
    }
    reader.endObject()

    return User(
    id = id ?: throw IllegalStateException(
    StringBuilder("Required property '").append("id")
    .append("' missing at ").append(reader).toString()),
    username = username ?: throw IllegalStateException(
    StringBuilder("Required property '").append("username")
    .append("' missing at ").append(reader).toString()),
    displayName = displayName ?: throw IllegalStateException(
    StringBuilder("Required property '").append("displayName")
    .append("' missing at ").append(reader).toString()),
    email = email ?: throw IllegalStateException(
    StringBuilder("Required property '").append("email")
    .append("' missing at ").append(reader).toString()),
    created = created ?: throw IllegalStateException(
    StringBuilder("Required property '").append("created")
    .append("' missing at ").append(reader).toString()),
    isPublic = isPublic ?: throw IllegalStateException(
    StringBuilder("Required property '").append("isPublic")
    .append("' missing at ").append(reader).toString())
    )
    }
    }


    object TweetParser {
    fun fromJson(reader: JsonReader): Tweet {
    var id: String? = null
    var userId: String? = null
    var content: String? = null
    var created: OffsetDateTime? = null

    reader.beginObject()
    while (reader.peek() != JsonToken.END_OBJECT) {
    when (reader.nextName()) {
    "id" -> id = reader.nextString() ?:
    throw IllegalStateException(
    StringBuilder("Non-null value '").append("id")
    .append("' was null at ").append(reader).toString())
    "userId" -> userId = reader.nextString() ?:
    throw IllegalStateException(
    StringBuilder("Non-null value '").append("userId")
    .append("' was null at ").append(reader).toString())
    "content" -> content = reader.nextString() ?:
    throw IllegalStateException(
    StringBuilder("Non-null value '").append("content")
    .append("' was null at ").append(reader).toString())
    "created" -> created = reader.nextString()?.let(OffsetDateTime::parse) ?:
    throw IllegalStateException(
    StringBuilder("Non-null value '").append("created")
    .append("' was null at ").append(reader).toString())
    else -> reader.skipValue()
    }
    }
    reader.endObject()

    return Tweet(
    id = id ?: throw IllegalStateException(
    StringBuilder("Required property '").append("id")
    .append("' missing at ").append(reader).toString()),
    userId = userId ?: throw IllegalStateException(
    StringBuilder("Required property '").append("userId")
    .append("' missing at ").append(reader).toString()),
    content = content ?: throw IllegalStateException(
    StringBuilder("Required property '").append("content")
    .append("' missing at ").append(reader).toString()),
    created = created ?: throw IllegalStateException(
    StringBuilder("Required property '").append("created")
    .append("' missing at ").append(reader).toString())
    )
    }
    }