✨ [common-util] Gson 의존성 및 GsonUtils 추가

util/common-util/build.gradle.kts

@@ -1,2 +1,3 @@
 dependencies {
+    implementation("com.google.code.gson:gson")
 }

util/common-util/src/main/kotlin/me/jiniworld/demohx/GsonUtils.kt

@@ -0,0 +1,87 @@
+package me.jiniworld.demohx
+
+import com.google.gson.FieldNamingPolicy
+import com.google.gson.GsonBuilder
+import com.google.gson.TypeAdapter
+import com.google.gson.stream.JsonReader
+import com.google.gson.stream.JsonWriter
+import mu.KotlinLogging
+import java.time.LocalDate
+import java.time.LocalDateTime
+import java.time.LocalTime
+import java.time.format.DateTimeFormatter
+
+object GsonUtils {
+    private val logger = KotlinLogging.logger {}
+
+    private val patternDate = "yyyy-MM-dd"
+    private val patternTime = "HH:mm:ss"
+    private val patternDateTime = "yyyy-MM-dd HH:mm:ss"
+
+    private val gson = GsonBuilder()
+        .disableHtmlEscaping()
+        .setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES)
+        .setDateFormat(patternDateTime)
+        .registerTypeAdapter(LocalDateTime::class.java, LocalDateTimeAdapter().nullSafe())
+        .registerTypeAdapter(LocalDate::class.java, LocalDateAdapter().nullSafe())
+        .registerTypeAdapter(LocalTime::class.java, LocalTimeAdapter().nullSafe())
+        .create()
+
+    fun toJson(obj: Any): String {
+        return gson.toJson(obj)
+    }
+
+    fun <T> fromJson(str: String, clazz: Class<T>): T {
+        return gson.fromJson(str, clazz)
+    }
+
+//    fun toJson(obj: Any): String? {
+//        val result = gson.toJson(obj)
+//        return if("null" == result) null else result
+//    }
+//
+//    fun <T> fromJson(str: String, clazz: Class<T>): T? {
+//        try {
+//            return gson.fromJson(str, clazz)
+//        } catch (e: JsonSyntaxException) {
+//            logger.error{ e.message }
+//        }
+//        return null
+//    }
+    
+    class LocalDateAdapter : TypeAdapter<LocalDate>() {
+        private val format: DateTimeFormatter = DateTimeFormatter.ofPattern(patternDate)
+
+        override fun write(writer: JsonWriter, value: LocalDate?) {
+            value?.let { writer.value(value.format(format)) }
+        }
+
+        override fun read(reader: JsonReader): LocalDate {
+            return LocalDate.parse(reader.nextString(), format)
+        }
+    }
+
+    class LocalDateTimeAdapter : TypeAdapter<LocalDateTime>() {
+        private val format: DateTimeFormatter = DateTimeFormatter.ofPattern(patternDateTime)
+
+        override fun write(writer: JsonWriter, value: LocalDateTime?) {
+            value?.let { writer.value(value.format(format)) }
+        }
+
+        override fun read(reader: JsonReader): LocalDateTime {
+            return LocalDateTime.parse(reader.nextString(), format)
+        }
+    }
+
+    class LocalTimeAdapter : TypeAdapter<LocalTime>() {
+        private val format: DateTimeFormatter = DateTimeFormatter.ofPattern(patternTime)
+
+        override fun write(writer: JsonWriter, value: LocalTime?) {
+            value?.let { writer.value(value.format(format)) }
+        }
+
+        override fun read(reader: JsonReader): LocalTime {
+            return LocalTime.parse(reader.nextString(), format)
+        }
+    }
+}