Top Eclipse Interview Questions & Answers:

1. What are the differences between Require-Bundle and Import-Package?

There are two complementary ways of depending on something from outside a given plug-in; Require-Bundle and Import-Package.

2. What is included in the Rich Client Platform?

Eclipse Runtime, SWt, JFace, Workbench

3. What is EMF?

The Eclipse Modeling Framework is a Java/XML framework for generating tools and other applications based on simple class models. EMF helps you rapidly turn models into efficient, correct, and easily customizable Java code. It is intended to provide the benefits of formal modeling, but with a very low cost of entry. In addition to code generation, it provides the ability to save objects as XML documents for interchange with other tools and applications.

4. What is optional dependency?

plug-in prerequisite elements can be made optional by adding the optional="true" attribute in Manifest file(see below for an example). Marking an import as optional simply states that if the specified plug-in is not found at runtime, the dependent plug-in should be left enabled. This is used when a plug-in can be used in many scenarios or it is reasonable to operate with reduced function. It allows the creation of minimal installs that cover functional subsets. Require-Bundle: org.eclipse.swt; optional="true"

5. How can I change the window icon in my application?

Define a product via the products extension point and specify the windowImages property to refer to two image files, a 16x16 one and a 32x32 one.

6. Is there a built-in facility to check whether a given value is valid compared to the effective facets of its type?

To determine if a literal is valid with respect to a simple type, you can use either XSDSimpleTypeDefinition.isValidLiteral or XSDSimpleTypeDefinition.assess.

7. How to resize my shell to get my changed widgets to lay out again?

A layout is only performed automatically on a Composite's children when the Composite is resized, including when it is initially shown. To make a Composite lay out its children under any other circumstances, such as when children are created or disposed, its layout() method must be called.

8. What is Display, what is Shell?

The Display class respresents the GUI process(thread), the Shell class represents windows.

9. Do we need to explicitly invoke org.eclipse.swt.graphics.Image.dispose()?

Application code must explicitly invoke the Image.dispose() method to release the operating system resources managed by each instance when those instances are no longer required. This is because that the Java finalization is too weak to reliably support management of operating system resources.

10. What is the classpath of a plug-in?

The OSGi parent class loader. (Java boot class loader by default); The exported libraries of all imported plug-ins; The declared libraries of the plug-in and all its fragments.