Hello!

1)Is it possible to understand which minimum Java version need (support) my code to run properly?

2)I use JFrame but that does not changes my icon on window?

Image logo = Toolkit.getDefaultToolkit().getImage("logo.png");
setIconImage(logo);

3)Also that code throws an Exception

Class<?> awtUtilitiesClass = Class.forName("com.sun.awt.AWTUtilities");
Method mSetWindowOpacity = awtUtilitiesClass.getMethod("setWindowOpacity", Window.class, float.class);
mSetWindowOpacity.invoke(null, this, Float.valueOf(0.75f));

Exception:
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at MainGUI.<init>(MainGUI.java:52)
at QuickJavaDnsChanger.OpenGUI(QuickJavaDnsChanger.java:128)
at QuickJavaDnsChanger.main(QuickJavaDnsChanger.java:45)
Caused by: java.awt.IllegalComponentStateException: The frame is decorated
at java.awt.Frame.setOpacity(Unknown Source)
at java.awt.Window$1.setOpacity(Unknown Source)
at com.sun.awt.AWTUtilities.setWindowOpacity(Unknown Source)
... 7 more

Can someone please help me about them?

Thank you!

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