In JDK 8 + JavaFX 8, when creating bindings using Bindings.selecXXX() methods, upon evaluating the value returned by calling the getter of the object, a NullPointerException is generated and printed on the error output. The NPE generated does not prevent the code from being executed.

No NPE is printed when using JDK 7 + JavaFX 2.x.

See the following code:

final Pane pane = new Pane();
final BooleanBinding fullsceenProperty = Bindings.selectBoolean(pane.sceneProperty(), "window", "fullscreen");
final DoubleBinding widthProperty = Bindings.selectDouble(pane.sceneProperty(), "window", "width");
final StringBinding titleProperty = Bindings.selectString(pane.sceneProperty(), "window", "title");

As is there is no error.
Now we evaluate the value of the bindings by calling the getValue() method on each:

System.out.printf("visible: %b", fullsceenProperty.getValue()).println();
System.out.printf("width: %f", widthProperty.getValue()).println();
System.out.printf("title: %s", titleProperty.getValue()).println();

We get the correct output in both JDK7 and JDK8:

visible: false
width: 0.000000
title: null

From the Bindings.selectXXX() methods documentations, these values are correct as the scene property of the pane object is currently set to Null (the pane has not been attached to a scene yet at this point).

However, in JDK8 we also have the following non-critical non-execution-stopping NullPointerException that are printed on the error output:

Mar 21, 2014 2:44:10 PM com.sun.javafx.binding.SelectBinding$SelectBindingHelper getObservableValue
WARNING: Exception while evaluating select-binding [window, fullscreen]
Mar 21, 2014 2:44:10 PM com.sun.javafx.binding.SelectBinding$SelectBindingHelper getObservableValue
INFO: Property 'window' in ReadOnlyObjectProperty [bean: Pane@6378623f, name: scene, value: null] is null
java.lang.NullPointerException
at com.sun.javafx.binding.SelectBinding$SelectBindingHelper.getObservableValue(SelectBinding.java:481)
at com.sun.javafx.binding.SelectBinding$AsBoolean.computeValue(SelectBinding.java:139)
at javafx.beans.binding.BooleanBinding.get(BooleanBinding.java:157)
at javafx.beans.binding.BooleanExpression.getValue(BooleanExpression.java:56)
at test.Main.start(Main.java:28)
at com.sun.javafx.application.LauncherImpl$8.run(LauncherImpl.java:837)
at com.sun.javafx.application.PlatformImpl$7.run(PlatformImpl.java:335)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:301)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:298)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:298)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39)
at com.sun.glass.ui.win.WinApplication$4$1.run(WinApplication.java:112)
at java.lang.Thread.run(Thread.java:744)

Mar 21, 2014 2:44:10 PM com.sun.javafx.binding.SelectBinding$SelectBindingHelper getObservableValue
WARNING: Exception while evaluating select-binding [window, width]
Mar 21, 2014 2:44:10 PM com.sun.javafx.binding.SelectBinding$SelectBindingHelper getObservableValue
INFO: Property 'window' in ReadOnlyObjectProperty [bean: Pane@6378623f, name: scene, value: null] is null
java.lang.NullPointerException
at com.sun.javafx.binding.SelectBinding$SelectBindingHelper.getObservableValue(SelectBinding.java:481)
at com.sun.javafx.binding.SelectBinding$AsDouble.computeValue(SelectBinding.java:190)
at javafx.beans.binding.DoubleBinding.get(DoubleBinding.java:203)
at javafx.beans.binding.DoubleExpression.getValue(DoubleExpression.java:70)
at test.Main.start(Main.java:29)
at com.sun.javafx.application.LauncherImpl$8.run(LauncherImpl.java:837)
at com.sun.javafx.application.PlatformImpl$7.run(PlatformImpl.java:335)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:301)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:298)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:298)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39)
at com.sun.glass.ui.win.WinApplication$4$1.run(WinApplication.java:112)
at java.lang.Thread.run(Thread.java:744)

Mar 21, 2014 2:44:10 PM com.sun.javafx.binding.SelectBinding$SelectBindingHelper getObservableValue
WARNING: Exception while evaluating select-binding [window, title]
Mar 21, 2014 2:44:10 PM com.sun.javafx.binding.SelectBinding$SelectBindingHelper getObservableValue
INFO: Property 'window' in ReadOnlyObjectProperty [bean: Pane@6378623f, name: scene, value: null] is null
java.lang.NullPointerException
at com.sun.javafx.binding.SelectBinding$SelectBindingHelper.getObservableValue(SelectBinding.java:481)
at com.sun.javafx.binding.SelectBinding$AsString.computeValue(SelectBinding.java:394)
at javafx.beans.binding.StringBinding.get(StringBinding.java:152)
at javafx.beans.binding.StringBinding.get(StringBinding.java:61)
at javafx.beans.binding.StringExpression.getValue(StringExpression.java:51)
at test.Main.start(Main.java:30)
at com.sun.javafx.application.LauncherImpl$8.run(LauncherImpl.java:837)
at com.sun.javafx.application.PlatformImpl$7.run(PlatformImpl.java:335)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:301)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:298)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:298)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39)
at com.sun.glass.ui.win.WinApplication$4$1.run(WinApplication.java:112)
at java.lang.Thread.run(Thread.java:744)

These NPE should not appear to the programmer or the documentation of the various Bindings.selectXXX() methods should be expanded to describe this behavior.