/**
		 Traverse all files 
		 Find these files , Maximum and minimum ( wrong 0) The file of , Print out their file names 
	 */
	public static void test1(List<File> files) {
		long maxSize = 0, minSize = Long.MAX_VALUE;
		File maxfile = null;
		File minfile = null;
		for(File f: files){
			if (f.length() > maxSize) {
				maxSize = f.length();
				maxfile = f;
			}
					
			if (f.length() != 0 && f.length() < minSize){
				minSize = f.length();				
				minfile = f;
			}
		}
		
		System.out.printf(" The biggest file is \t%s, Its size is \t%d%n", maxfile, maxSize);
		System.out.printf(" The smallest file is \t%s, Its size is \t%d", minfile, minSize);				
	}
	
	/**
	 *  Traverse the files under the folder and put them into the collection 
	 */
	public static void test2(File file, List<File> files) {
		File[] list = file.listFiles();
		for (File f : list) {
			if (f.isDirectory()){
				method(f, files);
			}else {
				files.add(f);
			}
		}
		test1(files);
	}
	
	/**
	 *  If it's a folder , Traverse and find the files and put them into the collection 
	 * @param file
	 */
	public static void method(File file, List<File> files) {
		File[] list = file.listFiles();
		for (File f : list) {
			if (f.isDirectory() && f.length() != 0) {
				method(f, files);
			}else if (f.isFile()) {
				files.add(f);				
			}
		}
	}

 practice 1: 
package com.how2j.io;

import java.io.File;
import java.util.ArrayList;

/**
 * @author ZachLgodNbb
 */
public class TestFile3 {
    /**
     *  practice :  Get the largest and smallest files in the file 
     * @param args
     */
    public static void main(String[] args) {
        File file = new File("C:\\Windows");
        // Receive files 
        ArrayList<File> newFile = new ArrayList<>();
        // obtain Windows All files under , Filter out folders 
        File[] files = file.listFiles();
        if (files != null) {
            for (File file1 : files){
                if (file1.isFile()){
                    newFile.add(file1);
                }
            }
        }
        // Sort by bubbling , Get the largest and smallest files 
        for(int i=0; i<newFile.size()-1;i++){
            for(int j=0;j<newFile.size()-1-i;j++){
                if(newFile.get(j).length() < newFile.get(j+1).length()){
                    File temp = newFile.get(j);
                    newFile.set(j,newFile.get(j+1));
                    newFile.set(j+1,temp);
                }
            }
        }
        System.out.println(" The biggest file is : "+newFile.get(0)+
                ", Its size is : "+newFile.get(0).length());
        System.out.println(" The biggest file is : "+newFile.get(newFile.size()-1)+
                ", Its size is : "+newFile.get(newFile.size()-1).length());
    }
}
-----------------------------------------------------------------------------------------------------
 practice 2:
package com.how2j.io;

import java.io.File;

/**
 * @author ZachLgodNbb
 */
public class TestFile4 {
    /**
     *  practice :  traverse folder  ( Include sub files )
     * @param file
     */
    public static void findAll(File file){
        // Determine whether the file exists 
        if (!file.exists()) {
            System.out.println(" File does not exist !");
        }
        // If it's a file , Print the address directly + File name 
        if (file.isFile()){
            System.out.println(file.getPath() +" "+ file.getName());
        }else {
            // If it's not a file , Then take the path , Get the file through the path , Traverse the file 
            File[] files =file.listFiles();
            if (files != null) {
                for (File f: files){
                    if (f == null){
                        break;
                    }else {
                        findAll(f);
                    }
                }
            }
        }
    }
    public static void main(String[] args) {
        // Use with care ...
        File file = new File("C:\\Windows");
        findAll(file);
    }
}

package Java Intermediate .IO Training ;

import java.io.File;
import java.util.Arrays;

public class  File object  {
    long max_length=0;
    String max_name="";
    long min_length=Long.MAX_VALUE;
    String min_name="";

    public static void main(String[] args) {
        File f = new File("C:\\Windows");
        File[] fs = f.listFiles();
         File object  w = new  File object ();
        w.Find(fs);
        System.out.printf(" The biggest file is %s, Its size is %d\n",w.max_name,w.max_length);
        System.out.printf(" The smallest file is %s, Its size is %d",w.min_name,w.min_length);
    }

    void Find(File[] fs){
        for (File f:fs){
            if(f.isDirectory()){
                if(f.listFiles()!=null) Find(f.listFiles());
            }
            else if(f.isFile()){
                if(f.length()>0) {
                    System.out.printf(" Get file %s Length ：%d\n",f.getAbsolutePath(),f.length());
                    if (max_length < f.length()) {
                        max_length = f.length();
                        max_name = f.getAbsolutePath();
                        ;
                    }
                    if (min_length > f.length()){
                        min_length = f.length();
                        min_name = f.getAbsolutePath();
                        ;
                    }
                }
            }
        }
    }
}

package org.example;

import com.sun.deploy.util.ArrayUtil;

import java.io.File;
import java.util.ArrayList;

public class TestFile {
    public static void main(String[] args) {
        File f = new File("D:/MongoDB");

        A a = new A();
        a.getmaxormin(f);

        System.out.println(" The biggest file is " + a.maxfile + ", Its size is " + a.maxsize + " Bytes ");
        System.out.println(" The smallest file is " + a.minfile + ", Its size is " + a.minsize + " Bytes ");

    }

class A {
    static long maxsize = 0;
    static long minsize = Integer.MAX_VALUE;
    static File maxfile = null;
    static File minfile = null;
    public void getmaxormin(File f) {
        File[] l = f.listFiles();
        for (int i = 0; i < l.length; i++) {
            if (l[i].isDirectory()) {
                System.out.println(l[i]);
                this.getmaxormin(l[i]);
            } else {
               // Find the maximum file here 
                if (l[i].length() > this.maxsize) {
                    this.maxsize = l[i].length();
                    this.maxfile = l[i];
                    System.out.println(l[i]);
                }
                // Here is the minimum file , Pay attention to removing 0 Byte file 
                if (l[i].length() < this.minsize && l[i].length() > 0) {
                    this.minsize = l[i].length();
                    this.minfile = l[i];
                    System.out.println(l[i]);
                }
            }
        }
    }
}

/**
 *  Traverse subfolders under a directory 
 */
public class ErgodicSubFile {
    public static void main(String[] args) {
        File myFile = new File("I:\\ Mobile phone photos ");
        ergodicSubfile(myFile);
    }

    public static void ergodicSubfile(File file) {
        if (!file.exists()) {
            throw new NoSuchFile(file + "is not exists");
        } else {
            File[] files = file.listFiles();
            for (File file1: files) {
                if (file1.isDirectory()) {
                    System.out.println(file1.getName());
                    ergodicSubfile(file1);
                    System.out.println();
                } else {
                    System.out.println(file1.getName());
                }
            }
        }
    }
}

class NoSuchFile extends RuntimeException {
    @java.io.Serial
    static final long serialVersionUID = -7034897190745L;

    public NoSuchFile() {
        super();
    }

    public NoSuchFile(String message) {
        super(message);
    }
}