Bug 21631 JavaUI.createTypeDialog() should provide default message [dialogs]
2.0 Release If you use JavaUI.createTypeDialog() to create a new (single selection) type dialog, and then open the dialog, the open will fail silently. The dialog cannot be succesfully opened unless you send setMessage() to the dialog before you open it. This behaviour should be documented, or, preferably, a default message ("Please select a type/class/interface") should be provided.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/JavaUI.java
* The id of the Java plugin (value <code>"org.eclipse.jdt.ui"</code>).
	 */	
	public static final String ID_PLUGIN= "org.eclipse.jdt.ui"; 
	
	/**
	 * The id of the Java perspective
	 * (value <code>"org.eclipse.jdt.ui.JavaPerspective"</code>).
	 */	
	public static final String ID_PERSPECTIVE= 		"org.eclipse.jdt.ui.JavaPerspective"; 
	
	/**
	 * The id of the Java hierarchy perspective
	 * (value <code>"org.eclipse.jdt.ui.JavaHierarchyPerspective"</code>).
	 */	
	public static final String ID_HIERARCHYPERSPECTIVE= "org.eclipse.jdt.ui.JavaHierarchyPerspective"; 
	/**
	 * The id of the Java action set
	 * (value <code>"org.eclipse.jdt.ui.JavaActionSet"</code>).
	 */
	public static final String ID_ACTION_SET= "org.eclipse.jdt.ui.JavaActionSet"; 
	/**
	 * The id of the Java Element Creation action set
	 * (value <code>"org.eclipse.jdt.ui.JavaElementCreationActionSet"</code>).
	 * 
	 * @since 2.0
	 */
	public static final String ID_ELEMENT_CREATION_ACTION_SET= "org.eclipse.jdt.ui.JavaElementCreationActionSet"; 
	
	/**
	 * The id of the Java Coding action set