Automatically download missing local files if an AliEn replica exists

src/ch/alice/o2/ccdb/servlets/SQLDownload.java

@@ -112,11 +112,17 @@ public class SQLDownload extends HttpServlet {
 
 		final String range = request.getHeader("Range");
 
-		final File localFile = obj.getLocalFile(false);
+		File localFile = obj.getLocalFile(false);
 
 		if (localFile == null) {
-			response.sendError(HttpServletResponse.SC_NOT_FOUND, "The file cannot be served by this server directly, the physical copy is not on this machine");
-			return;
+			// If it has an AliEn replica, and is supposed to be on the local machine then try to bring it to this server and serve it as requested
+			if (obj.replicas.contains(Integer.valueOf(-1)) && AsyncMulticastQueue.stage(obj))
+				localFile = obj.getLocalFile(false);
+
+			if (localFile == null) {
+				response.sendError(HttpServletResponse.SC_NOT_FOUND, "The file cannot be served by this server directly, the physical copy is not on this machine");
+				return;
+			}
 		}
 
 		if (range == null || range.trim().isEmpty()) {
@@ -280,7 +286,9 @@ public class SQLDownload extends HttpServlet {
 
 		response.setContentLengthLong(contentLength);
 
-		try (RandomAccessFile input = new RandomAccessFile(localFile, "r"); OutputStream output = response.getOutputStream()) {
+		try (
+				RandomAccessFile input = new RandomAccessFile(localFile, "r");
+				OutputStream output = response.getOutputStream()) {
 			final Iterator<Map.Entry<Long, Long>> itRange = requestedRanges.iterator();
 			final Iterator<String> itSubHeader = subHeaders.iterator();