Changes between Version 3 and Version 4 of CODE_TASKS_REQUIREMENTS

Timestamp:

09/16/08 17:55:02 (17 years ago)

Author:

Tanya

Comment:

--

CODE_TASKS_REQUIREMENTS

@@ -119 +119 @@
         }
 }}}
+
+= Switch statements =
+
+Very often the use of switch statements can be considered code smell.
+We should think of replacing the switch statement with polymorphism.
+Thus, this doesn't mean that switch statements are always code smell,but we should think whether we can avoid them before writing them.
+
+= Exception swallowing =
+
+Extremely large number of improper exception handlings appear in the code.
+NEVER swallow an exception!!!
+
+{{{
+         public void internalFrameActivated(InternalFrameEvent e) {
+                //show title bar
+                FrameView.this.observable.getInvoker().setFocus(true);
+                
+                try {
+                        getParentView().getParentView().swingRepresentation().setSelected(true);
+                } catch (PropertyVetoException e1) {
+                        // TODO - fix exception handling
+                        e1.printStackTrace();
+                }
+        }
+}}}
+
+Printing the stack trace is NOT exception handling,though it may be useful for debug.
+The fact that the method continues running the same way both if there is an exception and if there isn't in fact means that
+we are not interested in the result of the method in the 'try' clause.
+If we write the exception handling like this there is no matter if it works ok, or not - it is all the same for us.
+Indeed the example below is the same as if we write:
+
+{{{
+         public void internalFrameActivated(InternalFrameEvent e) {
+                FrameView.this.observable.getInvoker().setFocus(true);  
+        }
+}}}
+
+Always rethrow the exception if You dont have information how to handle it.
+Since PropertyVetoException is checked exception, it may be good to wrap it in a RuntimeException.
+Consult other people and think of exception handling policy.
+
+Proper exception handling, without change of the interface is:
+{{{
+        public void internalFrameActivated(InternalFrameEvent e) {
+                //show title bar
+                FrameView.this.observable.getInvoker().setFocus(true);
+                try {
+                        getParentView().getParentView().swingRepresentation().setSelected(true);
+                } catch (PropertyVetoException e1) {
+                        throw new RuntimeException(e1);
+                }
+        }
+}}}