RFR: 8357687: Remove unnecessary Map.containsKey from GraphicsEnvironment implementations

[Sergey Bylokhov]

On Sun, 27 Apr 2025 21:04:34 GMT, Andrey Turbanov <aturbanov at openjdk.org> wrote:

> `devices` contains only non-null values. It means instead of separate `containsKey` call we can just call `HashMap.get` and then compare result with `null`.

src/java.desktop/unix/classes/sun/awt/X11GraphicsEnvironment.java line 236:

> 234:         for (int id = 0; id < numScreens; ++id) {
> 235:             X11GraphicsDevice d = old.remove(id);
> 236:             devices.put(id, d != null ? d : new X11GraphicsDevice(id));

same can be done in CGraphicsEnvironment.java

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/24907#discussion_r2067795484