import java.io.File;import java.io.FilenameFilter;public class Main {    public static void main(String[] args) {       // write your code here        File file = new File("D:\\workspace\\IdeaProjects\\JavaBasics");        File[] files = file.listFiles();        printFiles(files);        File[] files2 = file.listFiles(new FilenameFilter() {            @Override            public boolean accept(File file, String s) {                return s.endsWith(".iml");            }        });        printFiles(files2);        listDirs(file, 4);    }    public static void printFiles(File[] files) {        System.out.println("====================================");        if (files != null) {            for (File file: files) {                System.out.println(file);            }        }        System.out.println("====================================");        System.out.println();    }    public static void listDirs(File file, int indent) {        if (file == null) {            return;        }        // indent-4: remove first dir indent        for (int i = 0; i < indent-4; i++) {            System.out.print(" ");        }        System.out.println(file.isDirectory()? file.getName()+File.separator : file.getName());        if (file.isDirectory()) {            File[] files = file.listFiles();            if (files != null) {                for (File f: files) {                    listDirs(f, indent + 4);                }            }        }    }}/*====================================D:\workspace\IdeaProjects\JavaBasics\.ideaD:\workspace\IdeaProjects\JavaBasics\JavaBasics.imlD:\workspace\IdeaProjects\JavaBasics\outD:\workspace\IdeaProjects\JavaBasics\src========================================================================D:\workspace\IdeaProjects\JavaBasics\JavaBasics.iml====================================JavaBasics\    .idea\        description.html        encodings.xml        misc.xml        modules.xml        project-template.xml        workspace.xml    JavaBasics.iml    out\        production\            JavaBasics\                com\                    shellever\                        java\                            Main$1.class                            Main.class    src\        com\            shellever\                java\                    Main.java*/