availability: adds check that datasets are mounted (try to read number of...

availability: adds check that datasets are mounted (try to read number of entries in the /srv/datasets dir)

data-access/servlet/src/main/java/vosi/VlkbServletFile.java

@@ -28,22 +28,58 @@ import static java.nio.file.StandardCopyOption.*;
 public class VlkbServletFile
     extends javax.servlet.http.HttpServlet
 {
-    // for logs and debug
    String className = this.getClass().getSimpleName();
+	private static final SearchSettings settings = Settings.getInstance();
+	private boolean available;
 
-// VOSI
-// String accessURL = null; // FIXME now read from MERGEURL later introduce own param
-// String funcName = "vlkb_cutout"; // FIXME read from config file
+	private String checkDatasets(String dirName)
+	{
+		Path dir = Paths.get(dirName);
+      String note;
+      try
+      {
+         int count = 0;
+         try (DirectoryStream<Path> stream = Files.newDirectoryStream(dir))
+         {
+            for (Path entry: stream) count++;
+            note = dir.toString() + " has " + String.valueOf(count) + " entries";
+				this.available = true;
+         }
+         catch (DirectoryIteratorException ex)
+         {
+            // I/O error during the iteration, the cause is an IOException
+            throw ex.getCause();
+         }
+      }
+      catch(Exception ex)
+      {
+         note = "error: " + ex.toString();
+			this.available = false;
+      }
 
-	private static final String availStr = 
+		return note;
+	}
+
+	private String availString()
+	{
+		String dirName = settings.fitsPaths.surveys();
+		String datasetsAvail = checkDatasets(dirName);
+
+		String availStr = 
 			"<?xml version=\"1.0\" encoding=\"UTF-8\"?>"
 			+ "<vosi:availability xmlns:vosi=\"http://www.ivoa.net/xml/VOSIAvailability/v1.0\">"
-		+ " <vosi:available>true</vosi:available>"
+			+ "<vosi:available> " +  ((this.available)?"true":"false") + " </vosi:available>"
 			+ "<vosi:note> VLKB-SODA " + Version.asString + " is accepting queries </vosi:note>"
+			+ "<vosi:note> " + datasetsAvail + " </vosi:note>"
 			+ "</vosi:availability>";
 
-	private String capsStr = null;
 
+		return availStr;
+	}
+
+
+
+	private String capsStr = null;
 
 	protected void SetCapsStr(String URL, String funcName)
 	{
@@ -138,7 +174,7 @@ public class VlkbServletFile
 			}
 			else if(-1 != requestURL.lastIndexOf("/availability"))
 			{
-			writer.println(availStr);	
+				writer.println(availString());	
 			}
 			// error FIXME what to do if none of above given ? e.g. misconfigured web.xml