Merged ClassPathExplorer fixes for #5953, #5957

svn changeset:15891/svn branch:6.5

1 files changed, 33 insertions, 11 deletions

diff --git a/src/com/vaadin/terminal/gwt/widgetsetutils/ClassPathExplorer.java b/src/com/vaadin/terminal/gwt/widgetsetutils/ClassPathExplorer.java
index f69cc468bf..077dd9c2f8 100644
--- a/src/com/vaadin/terminal/gwt/widgetsetutils/ClassPathExplorer.java
+++ b/src/com/vaadin/terminal/gwt/widgetsetutils/ClassPathExplorer.java
@@ -196,7 +196,8 @@ public class ClassPathExplorer {
                         } catch (MalformedURLException e) {
                             // should never happen as based on an existing URL,
                             // only changing end of file name/path part
-                            logger.log(Level.SEVERE,
+                            logger.log(
+                                    Level.SEVERE,
                                     "Error locating the widgetset " + classname,
                                     e);
                         }
@@ -524,30 +525,51 @@ public class ClassPathExplorer {
     @SuppressWarnings("unchecked")
     private static void tryToAdd(final String fullclassName,
             Collection<Class<? extends Paintable>> paintables) {
+        PrintStream out = System.out;
+        PrintStream err = System.err;
+        Throwable errorToShow = null;
+        Level logLevel = null;
         try {
-            PrintStream out = System.out;
-            PrintStream err = System.err;
             System.setErr(devnull);
             System.setOut(devnull);
 
             Class<?> c = Class.forName(fullclassName);
 
-            System.setErr(err);
-            System.setOut(out);
-
             if (c.getAnnotation(ClientWidget.class) != null) {
                 paintables.add((Class<? extends Paintable>) c);
                 // System.out.println("Found paintable " + fullclassName);
             } 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.
+            logLevel = Level.INFO;
+            errorToShow = e;
         } catch (ClassNotFoundException e) {
-            // e.printStackTrace();
+            // Don't show to avoid flooding the user with irrelevant messages
+            logLevel = Level.FINE;
+            errorToShow = e;
         } catch (LinkageError e) {
-            // NOP
+            // Don't show to avoid flooding the user with irrelevant messages
+            logLevel = Level.FINE;
+            errorToShow = e;
         } catch (Exception e) {
-            logger.log(Level.FINEST, "Could not add class: " + fullclassName, e);
+            // Don't show to avoid flooding the user with irrelevant messages
+            logLevel = 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 && logLevel != null) {
+            logger.log(logLevel,
+                    "Failed to load class " + fullclassName + ". "
+                            + errorToShow.getClass().getName() + ": "
+                            + errorToShow.getMessage());
         }
     }
 
@@ -615,4 +637,4 @@ public class ClassPathExplorer {
         }
     }
 
-}
\ No newline at end of file
+}