请教一下，这个应该怎么做

将以下代码转换为Lambda表达式（一行）
FilenameFilter ff = new FilenameFilter() {
@override
public boolean accept(File dir,String name) {
return name.endswith(".java")
}
}
String[] fileName = dir.list(ff);

FilenameFilter ff = (dir, name) -> name.endswith(".java")
String[] fileName = dir.list(ff);

 String[] list = dir.list((f, name) -> {
            return name.endsWith(".java");
        });