如何使用Flat Look & Feel

		<dependency>
			<groupId>com.formdev</groupId>
			<artifactId>flatlaf</artifactId>
			<version>3.1.1</version>
		</dependency>
		<dependency>
			<groupId>com.formdev</groupId>
			<artifactId>flatlaf-intellij-themes</artifactId>
			<version>3.1.1</version>
		</dependency>

		try {
			UIManager.setLookAndFeel(new FlatArcDarkIJTheme());
		} catch (UnsupportedLookAndFeelException ex) {
			Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex);
		}
		FlatLaf.setGlobalExtraDefaults(Collections.singletonMap("@accentColor", "#ffff00"));
		Class<? extends LookAndFeel> lafClass = UIManager.getLookAndFeel().getClass();
		try {
			FlatLaf.setup(lafClass.newInstance());
		} catch (InstantiationException ex) {
			Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex);
		} catch (IllegalAccessException ex) {
			Logger.getLogger(NewJFrame.class.getName()).log(Level.SEVERE, null, ex);
		}
		FlatLaf.updateUI();