Unbreak file serve ranges

src/main/java/sh/rhiobet/lalafin/file/FileServeService.java

@@ -46,10 +46,11 @@ public class FileServeService {
 	}
 
 	public Response serveFile(FileInfo fileInfo, String range) {
+		FileChannel channel = null;
 		try {
 			Path path = Paths.get(fileApiConfiguration.directory(),
 					URLDecoder.decode(fileInfo.directUrl, StandardCharsets.UTF_8));
-			FileChannel channel = FileChannel.open(path);
+			channel = FileChannel.open(path);
 			ResponseBuilder response;
 			long fileSize = channel.size();
 			if (range != null) {
@@ -64,13 +65,15 @@ public class FileServeService {
 					rangeEnd = Long.parseLong(rangeSplitted[1]);
 				}
 				if (rangeEnd + 1 > fileSize) {
+					channel.close();
 					return Response.status(
 							Response.Status.REQUESTED_RANGE_NOT_SATISFIABLE).build();
 				}
-				InputStream is = Channels.newInputStream(channel);
+
-				is.skip(rangeStart);
 				response = Response.ok(path.toFile());
-				response.entity(is.readNBytes((int) (rangeEnd + 1 - rangeStart)));
+				response.entity(new FileServeInputStream(Channels.newInputStream(channel),
+						rangeStart, rangeEnd));
+
 				response.header("Content-Length",
 						Long.toString(rangeEnd + 1 - rangeStart));
 				response.status(Response.Status.PARTIAL_CONTENT);
@@ -79,6 +82,7 @@ public class FileServeService {
 			} else {
 				response = Response.ok(path.toFile());
 				response.header("Content-Length", Long.toString(fileSize));
+				channel.close();
 			}
 			response.header("Accept-Ranges", "bytes");
 			response.header("Content-Disposition",
@@ -89,8 +93,52 @@ public class FileServeService {
 			}
 			return response.build();
 		} catch (IOException e) {
+			try {
+				channel.close();
+			} catch (Exception ignored) {}
 			return Response.status(Response.Status.INTERNAL_SERVER_ERROR).build();
 		}
 	}
 
 }
+
+class FileServeInputStream extends InputStream {
+	private InputStream is;
+	private long remaining;
+
+	public FileServeInputStream(InputStream is, long startRange, long endRange) throws IOException {
+		this.is = is;
+		try {
+			this.is.skip(startRange);
+		} catch (IOException e) {
+			try {
+				this.is.close();
+			} catch (Exception ignored) {}
+			throw e;
+		}
+		this.remaining = endRange + 1 - startRange;
+	}
+
+	@Override
+	public int read(byte[] buffer) throws IOException {
+		if (this.remaining == 0) {
+			this.is.close();
+			return -1;
+		} else {
+			int read = this.is.read(buffer, 0, (int) Math.min(buffer.length, this.remaining));
+			this.remaining -= read;
+			return read;
+		}
+	}
+
+	@Override
+	public int read() throws IOException {
+		if (this.remaining > 0) {
+			this.remaining--;
+			return this.is.read();
+		} else {
+			this.is.close();
+			return -1;
+		}
+	}
+}