Java bean exceptions

During normal development, exceptions are sometimes thrown by the Java™ beans. The visual editor displays icons and visual markers to indicate exceptions.

For example, when a visual class is instantiated or when property values are applied, a visual class might throw an exception. If an exception is thrown when a property value is applied, the Java bean is recreated and all the other valid properties are applied. A warning sign is shown in the Design view and the Java beans view to indicate that an exception occurred

exception warning sign
exception in Java bean view

When you select a component that has a warning, the status line shows you the property that threw the exception as well as the exception message. For example, if the text property of the button throws a run-time exception, the status bar shows the following status:

exception in status bar

When the exception is thrown during the application of a property value, the Java bean is recreated and the property ignored. The warning sign indicates that the representation of the live Java bean, as shown in the Design view or the Properties view, is incomplete, as the errant property has not been applied.

In addition to exceptions thrown when property values are applied, there might be an exception thrown during instantiation of the Java bean. In this case it is not possible to partially create the Java bean, as was done for bad property values, so no live Java bean is present. To indicate this, for errors thrown during instantiation of the Java bean, a red x is shown in the Design view and Java Beans view. You can select the Java bean to see the exception message in the status line.

exception in Design view

A Too complicated error, represented by a blue circle with an exclamation point, occurs when the initialization string for a property is too complicated for the visual editor to understand.


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