Add extension functions

README.md

@@ -10,9 +10,15 @@ You can build the project using Gradle.
 
 ## Usage
 
-* org.ktypeparser.MediaTypeParser.parse(inputStream: InputStream): MediaType?
-* org.ktypeparser.MediaTypeParser.parse(bytes: ByteArray): MediaType?
-* org.ktypeparser.MediaTypeParser.parse(file: File): MediaType?
+Functions:
+* detect(inputStream: InputStream): MediaType?
+* detect(bytes: ByteArray): MediaType?
+* detect(file: File): MediaType?
+
+Extension functions:
+* File.detectMediaType(): MediaType?
+* ByteArray.detectMediaType(): MediaType?
+* InputStream.detectMediaType(): MediaType?
 
 MediaType - is an enum with media types that can be determined by MIME Type
 

src/main/kotlin/org/ktypeparser/MediaTypeDetector.kt

@@ -0,0 +1,14 @@
+package org.ktypeparser
+
+import org.ktypeparser.processors.MediaTypeProcessor
+import org.ktypeparser.type.MediaType
+import java.io.File
+import java.io.InputStream
+
+fun File.detectMediaType() = detect(this)
+fun ByteArray.detectMediaType() = detect(this)
+fun InputStream.detectMediaType() = detect(this)
+
+fun detect(inputStream: InputStream): MediaType? = MediaTypeProcessor.detect(inputStream)
+fun detect(bytes: ByteArray): MediaType? = MediaTypeProcessor.detect(bytes)
+fun detect(file: File): MediaType? = MediaTypeProcessor.detect(file)

src/main/kotlin/org/ktypeparser/processors/MediaTypeProcessor.kt

@@ -3,10 +3,58 @@ package org.ktypeparser.processors
 import org.ktypeparser.type.MediaType
 import org.ktypeparser.type.parseMediaType
 import org.overviewproject.mime_types.MimeTypeDetector
+import java.io.ByteArrayInputStream
 import java.io.File
+import java.io.InputStream
+import java.nio.file.Files
+import java.nio.file.Paths
+import java.util.*
+
+internal object MediaTypeProcessor {
 
-object MediaTypeProcessor {
     private val mimeTypeDetector = MimeTypeDetector()
 
+    fun detect(inputStream: InputStream): MediaType? {
+        val tempFile = createTempFile(inputStream)
+        return detect(tempFile).also {
+            deleteTempFile(tempFile)
+        }
+    }
+
+    fun detect(bytes: ByteArray): MediaType? {
+        val tempFile = createTempFile(bytes)
+        return detect(tempFile).also {
+            deleteTempFile(tempFile)
+        }
+    }
+
+    fun detect(file: File): MediaType? {
+        return parseMediaType(file)
+    }
+
+    private fun deleteTempFile(file: File) = file.delete()
+
+    private fun createTempFile(bytes: ByteArray): File {
+        return createTempFile(ByteArrayInputStream(bytes))
+    }
+
+    private fun createTempFile(inputStream: InputStream): File = inputStream.use {
+        val outputTempFilePath = "$tempDirectory/$randomName"
+        Files.copy(it, Paths.get(outputTempFilePath))
+
+        try {
+            it.reset() //trying to reset input stream, if supported
+        } catch (_: Exception) {
+            //ignore reset
+        }
+        File(outputTempFilePath)
+    }
+
+    private val tempDirectory: String by lazy { System.getProperty("java.io.tmpdir") }
+
+    private val randomName: String
+        get() = UUID.randomUUID().toString()
+
     fun parseMediaType(file: File): MediaType? = mimeTypeDetector.detectMimeType(file)?.parseMediaType()
+
 }

src/test/kotlin/org/ktypeparser/MediaTypeParserTest.kt → src/test/kotlin/org/ktypeparser/MediaTypeDetectorTest.kt

@@ -7,60 +7,60 @@ import java.io.File
 import java.nio.file.Files
 import java.nio.file.Paths
 
-internal class MediaTypeParserTest {
+internal class MediaTypeDetectorTest {
 
     @Test
-    fun parse_pdfFile_rightType() {
+    fun detect_pdfFile_rightType() {
         val pdfFile = getFileFromResources("pdf.pdf")
 
-        val mediaType = MediaTypeParser.parse(pdfFile)
+        val mediaType = detect(pdfFile)
 
         Assertions.assertEquals(MediaType.PDF, mediaType)
     }
 
     @Test
-    fun parse_pdfFileByteArray_rightType() {
+    fun detect_pdfFileByteArray_rightType() {
         val pdfFile = getFileFromResources("pdf.pdf")
         val bytes = Files.readAllBytes(Paths.get(pdfFile.toURI()))
 
-        val mediaType = MediaTypeParser.parse(bytes)
+        val mediaType = detect(bytes)
 
         Assertions.assertEquals(MediaType.PDF, mediaType)
     }
 
     @Test
-    fun parse_pdfFileInputStream_rightType() {
+    fun detect_pdfFileInputStream_rightType() {
         val pdfFile = getFileFromResources("pdf.pdf")
 
-        val mediaType = MediaTypeParser.parse(pdfFile.inputStream())
+        val mediaType = detect(pdfFile.inputStream())
 
         Assertions.assertEquals(MediaType.PDF, mediaType)
     }
 
     @Test
-    fun parse_jpgFile_rightType() {
+    fun detect_jpgFile_rightType() {
         val jpgFile = getFileFromResources("jpg.jpg")
 
-        val mediaType = MediaTypeParser.parse(jpgFile)
+        val mediaType = detect(jpgFile)
 
         Assertions.assertEquals(MediaType.JPEG, mediaType)
     }
 
     @Test
-    fun parse_jpgFileByteArray_rightType() {
+    fun detect_jpgFileByteArray_rightType() {
         val jpgFile = getFileFromResources("jpg.jpg")
         val bytes = Files.readAllBytes(Paths.get(jpgFile.toURI()))
 
-        val mediaType = MediaTypeParser.parse(bytes)
+        val mediaType = detect(bytes)
 
         Assertions.assertEquals(MediaType.JPEG, mediaType)
     }
 
     @Test
-    fun parse_jpgFileInputStream_rightType() {
+    fun detect_jpgFileInputStream_rightType() {
         val jpgFile = getFileFromResources("jpg.jpg")
 
-        val mediaType = MediaTypeParser.parse(jpgFile.inputStream())
+        val mediaType = detect(jpgFile.inputStream())
 
         Assertions.assertEquals(MediaType.JPEG, mediaType)
     }