fix exception throw after sendError in DefaultServlet

- reduce debug exception logs in crawler

source/net/yacy/crawler/data/CrawlQueues.java

@@ -674,7 +674,6 @@ public class CrawlQueues {
                                 if (CrawlQueues.log.isFine()) {
                                     CrawlQueues.log.fine("problem loading " + request.url().toString() + ": " + e.getMessage());
                                 }
-                                e.printStackTrace();
                                 error = "load error - " + e.getMessage();
                             }
    
@@ -693,7 +692,6 @@ public class CrawlQueues {
                         }
                     } catch (final Exception e) {
                         CrawlQueues.this.errorURL.push(request.url(), request.depth(), profile, FailCategory.TEMPORARY_NETWORK_FAILURE, e.getMessage() + " - in worker", -1);
-                        ConcurrentLog.logException(e);
                         request.setStatus("worker-exception", WorkflowJob.STATUS_FINISHED);
                     } finally {
                         request = null;

source/net/yacy/http/servlets/YaCyDefaultServlet.java

@@ -460,6 +460,7 @@ public class YaCyDefaultServlet extends HttpServlet  {
         } catch (IllegalArgumentException iae) {
             if (!response.isCommitted()) {
                 response.sendError(HttpServletResponse.SC_BAD_REQUEST, iae.getMessage());
+                return false;
             }
             throw iae;
         }
@@ -1075,9 +1076,9 @@ public class YaCyDefaultServlet extends HttpServlet  {
                         filecontent = item.getInputStream();
                         files.put(new AbstractMap.SimpleEntry<String, byte[]>(item.getFieldName(), FileUtils.read(filecontent)));
                     } catch (IOException e) {
-                        ConcurrentLog.logException(e);
+                        ConcurrentLog.info("FILEHANDLER", e.getMessage());
                     } finally {
-                        if (filecontent != null) try {filecontent.close();} catch (IOException e) {ConcurrentLog.logException(e);}
+                        if (filecontent != null) try {filecontent.close();} catch (IOException e) {ConcurrentLog.info("FILEHANDLER", e.getMessage());}
                     }
                 }
             }
@@ -1108,7 +1109,7 @@ public class YaCyDefaultServlet extends HttpServlet  {
                 for (int j = 0; j < t; j++) p[j].join();
             }
         } catch (Exception ex) {
-            ConcurrentLog.logException(ex);
+            ConcurrentLog.info("FILEHANDLER", ex.getMessage());
         }
     }