From fac3268539e2a4fc993bfd01362a90ab607088a8 Mon Sep 17 00:00:00 2001
From: Artur Signell <artur.signell@itmill.com>
Date: Fri, 5 Nov 2010 15:38:53 +0000
Subject: [PATCH] #5957 - ClassPathExplorer should show
 UnsupportedClassVersionError

svn changeset:15886/svn branch:6.4
---
 .../gwt/widgetsetutils/ClassPathExplorer.java | 30 ++++++++++++++++---
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/src/com/vaadin/terminal/gwt/widgetsetutils/ClassPathExplorer.java b/src/com/vaadin/terminal/gwt/widgetsetutils/ClassPathExplorer.java
index 45b3d5a1c9..06876e44c5 100644
--- a/src/com/vaadin/terminal/gwt/widgetsetutils/ClassPathExplorer.java
+++ b/src/com/vaadin/terminal/gwt/widgetsetutils/ClassPathExplorer.java
@@ -525,6 +525,8 @@ public class ClassPathExplorer {
             Collection<Class<? extends Paintable>> paintables) {
         PrintStream out = System.out;
         PrintStream err = System.err;
+        Throwable errorToShow = null;
+
         try {
             System.setErr(devnull);
             System.setOut(devnull);
@@ -537,17 +539,37 @@ public class ClassPathExplorer {
             } else if (c.getAnnotation(ClientCriterion.class) != null) {
                 acceptCriterion.add((Class<? extends AcceptCriterion>) c);
             }
-
+        } catch (UnsupportedClassVersionError e) {
+            // Inform the user about this as the class might contain a Paintable
+            // Typically happens when using an add-on that is compiled using a
+            // newer Java version.
+            errorToShow = e;
         } catch (ClassNotFoundException e) {
-            // e.printStackTrace();
+            // Don't show to avoid flooding the user with irrelevant messages
+            if (logger.isLoggable(Level.FINE)) {
+                errorToShow = e;
+            }
         } catch (LinkageError e) {
-            // NOP
+            // Don't show to avoid flooding the user with irrelevant messages
+            if (logger.isLoggable(Level.FINE)) {
+                errorToShow = e;
+            }
         } catch (Exception e) {
-            e.printStackTrace();
+            // Don't show to avoid flooding the user with irrelevant messages
+            if (logger.isLoggable(Level.FINE)) {
+                errorToShow = e;
+            }
         } finally {
             System.setErr(err);
             System.setOut(out);
         }
+
+        // Must be done here after stderr and stdout have been reset.
+        if (errorToShow != null) {
+            logger.warning("Failed to load class " + fullclassName + ". "
+                    + errorToShow.getClass().getName() + ": "
+                    + errorToShow.getMessage());
+        }
     }
 
     /**
-- 
2.39.5