com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel这个缺少

[evenlyu]

java.lang.ClassNotFoundException: com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:583)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
at java.base/java.lang.Class.forName0(Native Method)
at java.base/java.lang.Class.forName(Class.java:415)
at java.desktop/javax.swing.SwingUtilities.loadSystemClass(SwingUtilities.java:2036)
at java.desktop/javax.swing.UIManager.setLookAndFeel(UIManager.java:632)
at test.One.<init>(One.java:17)
at test.One.main(One.java:10)

新安装的jdk12，想试试换个皮肤，提示以上错误

附上代码：
public class One extends JFrame{

public static void main(String[] args)
{
new One();

}

One(){
try {
UIManager
.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
} catch (Exception e) {
e.printStackTrace();
}
this.setSize(1320, 750);
this.setVisible(true);
this.setLocationRelativeTo(null);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
}
}

[evenlyu]

想知道是什么错误，该如何修改，麻烦各位大神了

[Franky ?]

没导入这个jar包，建议设置idea自动下载jar包