Delete temporary file on close

A temp file is created when reading an HdfFile from an InputStream.
Delete the temp file when the HdfFile is closed, or at application exit
if the HdfFile was never closed.

Fixes #262

jhdf/src/main/java/io/jhdf/HdfFile.java

@@ -36,10 +36,8 @@
 import java.nio.ByteBuffer;
 import java.nio.channels.FileChannel;
 import java.nio.file.FileSystems;
-import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.nio.file.StandardCopyOption;
 import java.nio.file.StandardOpenOption;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -156,24 +154,15 @@ private HdfFile(HdfBackingStorage hdfBackingStorage) {
 
 	/**
 	 * Opens an {@link HdfFile} from an {@link InputStream}. The stream will be read fully into a temporary file. The
-	 * file will be cleaned up at application exit.
+	 * file will be deleted when the HdfFile is closed, or at application exit if it was never closed.
 	 *
 	 * @param inputStream the {@link InputStream} to read
 	 * @return HdfFile instance
 	 * @see HdfFile#fromBytes(byte[])
 	 * @see HdfFile#fromByteBuffer(ByteBuffer)
 	 */
 	public static HdfFile fromInputStream(InputStream inputStream) {
-		try {
-			Path tempFile = Files.createTempFile(null, "-stream.hdf5"); // null random file name
-			logger.info("Creating temp file [{}]", tempFile.toAbsolutePath());
-			tempFile.toFile().deleteOnExit(); // Auto cleanup
-			Files.copy(inputStream, tempFile, StandardCopyOption.REPLACE_EXISTING);
-			logger.debug("Read stream to temp file [{}]", tempFile.toAbsolutePath());
-			return new HdfFile(tempFile);
-		} catch (IOException e) {
-			throw new HdfException("Failed to open input stream", e);
-		}
+		return TempHdfFile.fromInputStream(inputStream);
 	}
 
 	public HdfFile(Path hdfFile) {

jhdf/src/main/java/io/jhdf/TempHdfFile.java

@@ -0,0 +1,42 @@
+package io.jhdf;
+
+import io.jhdf.exceptions.HdfException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
+
+class TempHdfFile extends HdfFile {
+	private static final Logger logger = LoggerFactory.getLogger(TempHdfFile.class);
+
+	private TempHdfFile(Path tempFile) {
+		super(tempFile);
+	}
+
+	@Override
+	public void close() {
+		super.close();
+		logger.info("Deleting temp file on close [{}]", getFileAsPath().toAbsolutePath());
+		boolean deleteSuccess = getFile().delete();
+		if (!deleteSuccess) {
+			logger.warn("Could not delete temp file [{}]", getFileAsPath().toAbsolutePath());
+		}
+	}
+
+	public static TempHdfFile fromInputStream(InputStream inputStream) {
+		try {
+			Path tempFile = Files.createTempFile(null, "-stream.hdf5"); // null random file name
+			logger.info("Creating temp file [{}]", tempFile.toAbsolutePath());
+			tempFile.toFile().deleteOnExit(); // Auto cleanup in case close() is never called
+			Files.copy(inputStream, tempFile, StandardCopyOption.REPLACE_EXISTING);
+			logger.debug("Read stream to temp file [{}]", tempFile.toAbsolutePath());
+			return new TempHdfFile(tempFile);
+		} catch (IOException e) {
+			throw new HdfException("Failed to open input stream", e);
+		}
+	}
+}

jhdf/src/test/java/io/jhdf/HdfFileTest.java

@@ -47,8 +47,7 @@
 import static org.hamcrest.Matchers.nullValue;
 import static org.hamcrest.Matchers.sameInstance;
 import static org.hamcrest.Matchers.startsWith;
-import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
-import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.*;
 
 class HdfFileTest {
 
@@ -316,6 +315,17 @@ void testReadingFromStreamThrowsWhenStreamCantBeRead() throws IOException {
 		}
 	}
 
+	@Test
+	void testReadingFromStreamDeletesTempFileOnClose() throws IOException {
+		File tempFile;
+		try (InputStream inputStream = this.getClass().getResource(HDF5_TEST_FILE_PATH).openStream();
+			 HdfFile hdfFile = HdfFile.fromInputStream(inputStream)) {
+			tempFile = hdfFile.getFile();
+			assertTrue(tempFile.exists());
+		}
+		assertFalse(tempFile.exists());
+	}
+
 	@Test
 	void testLoadingInMemoryFile() throws IOException, URISyntaxException {
 		Path path = Paths.get(this.getClass().getResource(HDF5_TEST_FILE_PATH).toURI());