net.pwall.json.JSONSerializer.kt Maven / Gradle / Ivy
/*
* @(#) JSONSerializer.kt
*
* json-kotlin Kotlin JSON Auto Serialize/deserialize
* Copyright (c) 2019 Peter Wall
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package net.pwall.json
import kotlin.reflect.KClass
import kotlin.reflect.KFunction
import kotlin.reflect.KParameter
import kotlin.reflect.KProperty
import kotlin.reflect.KType
import kotlin.reflect.full.isSubclassOf
import java.time.Instant
import java.time.LocalDate
import java.time.LocalDateTime
import java.time.OffsetDateTime
import java.time.OffsetTime
import java.time.Year
import java.time.YearMonth
import java.time.ZonedDateTime
import java.util.BitSet
import java.util.Calendar
import java.util.Date
import java.util.Enumeration
import java.util.UUID
import net.pwall.json.annotation.JSONIgnore
import net.pwall.json.annotation.JSONName
import net.pwall.util.Strings
/**
* JSON Auto serialize for Kotlin.
*
* @author Peter Wall
*/
object JSONSerializer {
fun serialize(obj: Any?): JSONValue? {
if (obj == null)
return null
when (obj) {
is JSONValue -> return obj
is CharSequence -> return JSONString(obj)
is Char -> return JSONString(StringBuilder().append(obj))
is Number -> return serializeNumber(obj)
is Boolean -> return if (obj) JSONBoolean.TRUE else JSONBoolean.FALSE
is CharArray -> return JSONString(StringBuilder().append(obj))
is Array<*> -> return serializeArray(obj)
}
try {
findToJSON(obj::class)?.let { return it.call(obj) }
}
catch (e: Exception) {
throw JSONException("Error in custom toJSON - ${obj::class.simpleName}", e)
}
when (obj) {
is Iterable<*> -> return JSONArray(obj.map { serialize(it) })
is Iterator<*> -> return JSONArray().apply { obj.forEach { add(serialize(it)) } }
is Sequence<*> -> return JSONArray().apply { obj.forEach { add(serialize(it)) } }
is Enumeration<*> -> return JSONArray().apply { obj.forEach { add(serialize(it)) } }
is Map<*, *> -> return serializeMap(obj)
is Enum<*> -> return JSONString(obj.toString())
is Calendar -> return serializeCalendar(obj)
is Date -> return serializeDate(obj)
is Instant,
is LocalDate,
is LocalDateTime,
is OffsetTime,
is OffsetDateTime,
is ZonedDateTime,
is Year,
is YearMonth,
is UUID -> return JSONString(obj.toString())
is BitSet -> return serializeBitSet(obj)
}
val result = JSONObject()
obj::class.members.forEach { member ->
if (member is KProperty<*>) {
val combinedAnnotations = ArrayList(member.annotations)
obj::class.constructors.firstOrNull()?.parameters?.find { it.name == member.name }?.let {
combinedAnnotations.addAll(it.annotations)
}
if (findAnnotation(combinedAnnotations) == null) {
val name = findAnnotation(combinedAnnotations)?.name ?: member.name
val value = member.getter.call(obj)
if (value != null)
result[name] = serialize(value)
}
}
}
return result
}
@Suppress("UNCHECKED_CAST")
private fun findAnnotation(cls: KClass, annotations: List): T? {
for (annotation in annotations) {
if (annotation::class.isSubclassOf(cls))
return annotation as T?
}
return null
}
private inline fun findAnnotation(annotations: List): T? =
findAnnotation(T::class, annotations)
private fun serializeNumber(number: Number): JSONValue = when (number) {
is Int -> JSONInteger(number)
is Long -> JSONLong(number)
is Short -> JSONInteger(number.toInt())
is Byte -> JSONInteger(number.toInt())
is Float -> JSONFloat(number)
else -> JSONDouble(number.toDouble())
}
private fun serializeArray(array: Array<*>): JSONValue {
if (array.isArrayOf())
return JSONString(StringBuilder().apply { array.forEach { append(it) } })
return JSONArray(array.map { serialize(it) })
}
private fun serializeMap(map: Map<*, *>): JSONObject {
return JSONObject().apply {
map.entries.forEach { entry ->
this[entry.key.toString()] = serialize(entry.value)
}
}
}
private fun serializeCalendar(cal: Calendar) = JSONString(StringBuilder().apply {
Strings.appendPositiveInt(this, cal.get(Calendar.YEAR))
append('-')
Strings.append2Digits(this, cal.get(Calendar.MONTH) + 1)
append('-')
Strings.append2Digits(this, cal.get(Calendar.DAY_OF_MONTH))
append('T')
Strings.append2Digits(this, cal.get(Calendar.HOUR_OF_DAY))
append(':')
Strings.append2Digits(this, cal.get(Calendar.MINUTE))
append(':')
Strings.append2Digits(this, cal.get(Calendar.SECOND))
append('.')
Strings.append3Digits(this, cal.get(Calendar.MILLISECOND))
val offset = (cal.get(Calendar.ZONE_OFFSET) +
if (cal.timeZone.inDaylightTime(cal.time)) cal.get(Calendar.DST_OFFSET) else 0) /
60_000
if (offset == 0)
append('Z')
else {
append(if (offset < 0) '-' else '+')
val absOffset = Math.abs(offset)
Strings.append2Digits(this, absOffset / 60)
append(':')
Strings.append2Digits(this, absOffset % 60)
}
})
private fun serializeDate(date: Date): JSONString {
val cal = Calendar.getInstance()
cal.time = date
return serializeCalendar(cal)
}
private fun serializeBitSet(bitSet: BitSet) = JSONArray(ArrayList().apply {
(0 until bitSet.length()).forEach { i -> if (bitSet.get(i)) add(JSONInteger(i)) }
})
private val toJsonCache = HashMap, KFunction>()
private fun findToJSON(objClass: KClass<*>): KFunction? {
toJsonCache[objClass]?.let { return it }
try {
objClass.members.forEach { function ->
if (function is KFunction<*> &&
function.name == "toJSON" &&
function.parameters.size == 1 &&
function.parameters[0].kind == KParameter.Kind.INSTANCE &&
function.returnType.isJSONValue())
@Suppress("UNCHECKED_CAST")
return (function as KFunction).apply { toJsonCache[objClass] = this }
}
}
catch (ignore: kotlin.reflect.jvm.internal.KotlinReflectionInternalError) {
// seems like a bug in Kotlin runtime
}
catch (ignore: Exception) {
}
return null
}
private fun KType.isJSONValue(): Boolean {
classifier?.let { if (it is KClass<*>) return it.isSubclassOf(JSONValue::class) }
return false
}
private fun Enumeration.forEach(action: (T) -> Unit) {
while (hasMoreElements())
action(nextElement())
}
}
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