You apparently did a static import of Arc2D, creating an ambiguous reference between Arc2D.Double (since statically imported, now just Double) and the Double wrapper class. To fix it either don't import the static content of Arc2D or refer to the Double you are interested in using the fully qualified name java.lang.Double wherever you need to use it.
The import of Arc2D.Double doesn't need to be static; you can also import nested classes as follows:
Instead of using this import for Arc2D.Double and typing java.lang.Double fully, I would do it the other way around:
- change the import to java.awt.geom.Arc2D;
- use Double for java.lang.Double
- use Arc2D.Double for java.awt.geom.Arc2D.Double
Everybody who sees "Double" expects that to be java.lang.Double, and with the above naming you don't break that expectation.
Also, I'm a lazy git, and Arc2D.Double is shorter than java.lang.Double