Some help please in understanding JavaFX 2.0 Generics API definition

Question

In the Javadocs for JavaFX there is a set of helper/builder classes - for example
Class LineChartBuilder<X,Y,B extends LineChartBuilder<X,Y,B>>
which has method definitions (+ others)
public LineChart<X,Y> build()
public static <X,Y> LineChartBuilder<X,Y,?> create()
code snippet
     //     x-Axis marks
xAxisList = FXCollections.observableArrayList();
     xAxisList.add("One");
     xAxisList.add("Two");
     xAxisList.add("Three");
     xAxisList.add("Four");
     xAxisList.add("Five");
     CategoryAxis catXAxis = new CategoryAxis(xAxisList);
     //     y-Axis
     NumberAxis yAxis = new NumberAxis("Price", 0, 100, 10);
LineChartBuilder<CategoryAxis, NumberAxis, ?> builder;
???? What does the create() invocation look like ??????
     LineChart<X, y> chart = builder.build();
code snippet
any help would be greatly appreciated -
am still trying to get my mind around how to read these Generics signatures
Edited by: smaric on Feb 8, 2012 11:47 AM

Answer 1

EJP wrote:
public static <X,Y> LineChartBuilder<X,Y,?> create()
LineChartBuilder<CategoryAxis, NumberAxis, ?> builder;
???? What does the create() invocation look like ??????
LineChartBuilder<A,B,C> builder = LineChartBuilder.create();where A, B, C are whatever you need them to be.
LineChartBuilder<A,B,C> builder = LineChartBuilder.create();where A, B, C are whatever you need them to be.I get the Type idea
But C needs to be of Type LineChartBuilder<X,Y,B> according to the Class definition
public class LineChartBuilder<X,Y,B extends LineChartBuilder<X,Y,B>> extends XYChartBuilder<X,Y,B>and this is where I'm struggling - how do I break out of the B extends part of the definition -- for the following
LineChartBuilder<CategoryAxis, NumberAxis, B> builder = LineChartBuilder.create();The above does not compile -
B cannot be resolved to a type
The method create() is ambiguous for the type LineChartBuilder
Thanks for your help