build.gradle.kts

@@ -70,6 +70,9 @@ dependencies {
     implementation("org.apache.poi:poi-ooxml:5.2.3")
     implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.4")
 
+    // file mimetype check
+    implementation("org.apache.tika:tika-core:3.2.0")
+
     developmentOnly("org.springframework.boot:spring-boot-devtools")
     runtimeOnly("com.h2database:h2")
     runtimeOnly("com.mysql:mysql-connector-j")

src/main/kotlin/kr/co/vividnext/sodalive/explorer/profile/creatorCommunity/CreatorCommunityService.kt

@@ -21,6 +21,7 @@ import kr.co.vividnext.sodalive.fcm.FcmEventType
 import kr.co.vividnext.sodalive.member.Member
 import kr.co.vividnext.sodalive.member.block.BlockMemberRepository
 import kr.co.vividnext.sodalive.utils.generateFileName
+import kr.co.vividnext.sodalive.utils.validateImage
 import org.springframework.beans.factory.annotation.Value
 import org.springframework.context.ApplicationEventPublisher
 import org.springframework.data.repository.findByIdOrNull
@@ -71,6 +72,8 @@ class CreatorCommunityService(
             throw SodaException("오디오 등록을 위해서는 이미지가 필요합니다.")
         }
 
+        postImage?.let { validateImage(it, request.price > 0) }
+
         val post = CreatorCommunity(
             content = request.content,
             price = request.price,
@@ -129,6 +132,8 @@ class CreatorCommunityService(
         val post = repository.findByIdAndMemberId(id = request.creatorCommunityId, memberId = member.id!!)
             ?: throw SodaException("잘못된 요청입니다.")
 
+        postImage?.let { validateImage(it, post.price > 0) }
+
         if (request.content != null) {
             post.content = request.content
         }

src/main/kotlin/kr/co/vividnext/sodalive/utils/ImageValidation.kt

@@ -0,0 +1,21 @@
+package kr.co.vividnext.sodalive.utils
+
+import kr.co.vividnext.sodalive.common.SodaException
+import org.apache.tika.Tika
+import org.springframework.web.multipart.MultipartFile
+
+/**
+ * 이미지 파일인지 확인하고,
+ * GIF의 경우 외부 조건(gifAllowed)에 따라 허용 여부 판단
+ */
+fun validateImage(file: MultipartFile, gifAllowed: Boolean) {
+    val mimeType = Tika().detect(file.bytes)
+
+    if (!mimeType.startsWith("image/")) {
+        throw SodaException("이미지 파일만 업로드할 수 있습니다.")
+    }
+
+    if (mimeType == "image/gif" && !gifAllowed) {
+        throw SodaException("GIF 파일은 유료 게시물만 업로드 할 수 있습니다.")
+    }
+}