Memo: [Java] Check the contents of the directory

background

I wanted to check and extract the data in the directory, so I will write down the code at that time.

** Export all the contents of the directory **

This time, check the inside of the directory called tedkuma / BOX on the C drive. This file is included.

test.java

import java.io.File;

public class test {

  public static void main(String[] args) {

    File dir = new File("C:/tedkuma/BOX");  //Create an object of File class and specify the target directory
    File[] list = dir.listFiles();          //Get a list of files using listFiles
    for(int i=0; i<list.length; i++) {
      // System.out.println(list[i].toString());     //full path
      System.out.println(list[i].getName());      //File name only
    }
  }
}

When I run the above code ... it's in the BOX directory All directories such as csv files, png files, and new folders have been exported.

** System.out.println (list [i] .getName ()); ** If you rewrite the **. getName () ** part of ** to **. ToString () ** You can get the file name with the full path like this.

** Export only the file **

This time, do not write the directory, just the file. If it's a file, it's done. If it's a directory, it's done. ** if (list [i] .isFile ()) {** and ** if (list [i] .isDirectory ()) {** have been added. Since nothing is written in if (list [i] .isDirectory ()) {, the directory is not written.

test.java

import java.io.File;

public class test {

  public static void main(String[] args) {
    
    File dir = new File("C:/tedkuma/BOX");
    File[] list = dir.listFiles();
    for(int i=0; i<list.length; i++) {
      if(list[i].isFile()) {          //For files
        System.out.println(list[i].getName());
      }
      else if(list[i].isDirectory()) { //For directories
        //do nothing
      }
    }
  }
}

I will try it. Outputs other than the directory.

** Export only CSV file **

You can use contains () to find out if a string is included. Since the file name can be obtained by **. GetName () ** above, add ** contains () ** after it to search for the character string. I want to find CSV, so I wrote it as if **. Csv ** was included.

test.java

import java.io.File;

public class test {

  public static void main(String[] args) {

    File dir = new File("C:/tedkuma/BOX");
    File[] list = dir.listFiles();
    for(int i=0; i<list.length; i++) {
      if(list[i].getName().contains(".csv")) {
        System.out.println(list[i].getName());
      }else{
        //do nothing
      }
    }
  }
}

I will try it. No pngs or directories are written, only csv files are written.

** Export files with ★ in the file name **

It's exactly the same as above, but just in case ... I just changed ** ".csv" ** to ** "★" **.

test.java

import java.io.File;

public class test {

  public static void main(String[] args) {

    File dir = new File("C:/tedkuma/BOX");
    File[] list = dir.listFiles();
    for(int i=0; i<list.length; i++) {
      if(list[i].getName().contains("★")) {
        System.out.println(list[i].getName());
      }else{
        //do nothing
      }
    }
  }
}

I will try it. Only files with a star in the file name have been exported ~: grinning:

This time is over.