Read 30 minutes before going to bed every day_ day3_ Files

One 、 Operation file ：

Path and Files Class encapsulates all the functions needed to process the file system on the user's machine .

1.Path class

Method ：

• 1.// Get file path
• Paths.get（“ route ”）
• Paths.get(“/home”,“my”)
  /home/my

By the above methods , After getting the file path , It can be done by Path Class object , Call some methods below ,

•          path.getFileName()
  

•          path.getParent()
  

•          path.getRoot()
  

•           path.getFileSystem()
  

2. Files class

Method ：

• Method ：

•  Files.readAllBytes(path)  // Read all the contents of the file 
  

•  Files.readAllLines(path)  // Read line by line 
  

•  Files.exists（path）    // Determine whether the directory or file exists 
  

•  Files.createDirectory(path)   
  

•  Files.createFile(path)
  

•  Files.deleteIfExists（path）
  

•  Files.delete() // Delete directly without judgment 
  

3. Code test of the above method ：

/** * @Author Janson * @Date 2022/4/18 10:12 * @Version 1.0 */

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.List;

/** * Paths  class  *  Method ： * Paths.get（" route "） * Paths.get("/home","my") * /home/my * path.getFileName() * path.getParent() * path.getRoot() * path.getFileSystem() * Files  class  *  Method ： * Files.readAllBytes(path) * Files.readAllLines(path) * Files.exists（path） * Files.createDirectory(path) * Files.createFile(path) * Files.deleteIfExists（path） * Files.delete() // Delete directly without judgment  * */
public class NioPrac {
    
    public static void main(String[] args) throws IOException {
    
        // Get the absolute path of the current user （ The path above the relative path ）
        String userDir = System.getProperty("user.dir");
        System.out.println(userDir);
        Path path = Paths.get(userDir, "testData/longWord");
        System.out.println(path);
        //Paths  Method tests in classes 
        System.out.println("1 " + path.getFileName());
        System.out.println("2 " + path.getParent());
        System.out.println("3 " + path.getRoot());
        System.out.println("4 " + path.getFileSystem());

        List<String> strings = Files.readAllLines(path);
        strings.forEach(string-> System.out.println("stringArrays======>" + string));
        String stringArray = new String(Files.readAllBytes(path));
        //for (s stringByte : stringArrays) {
    
        // System.out.println("stringByte ======> " + stringByte);
        //}
        System.out.println("stringArray--------=====>" + stringArray);

        // Judge before creating the directory , Whether the directory exists 
        boolean exists = Files.exists(Paths.get("O:\\code\\BeforeSleeping30m\\testData\\my2"));
        if (!exists) {
    
            Path directory = Files.createDirectory(Paths.get("O:\\code\\BeforeSleeping30m\\testData\\my2"));
            System.out.println("directory====>"+ directory);
        }

        // create a file , Determine whether there is a file before creating , If exist , Do not create 
        boolean existsFile = Files.exists(Paths.get("O:\\code\\BeforeSleeping30m\\testData\\my\\my2.txt"));
        if (!existsFile) {
    
            Path file = Files.createFile(Paths.get("O:\\code\\BeforeSleeping30m\\testData\\my\\my2.txt"));
            System.out.println(" The newly created file The path of ：" + file);
        }

        boolean deleteIfExists = Files.deleteIfExists(Paths.get("O:\\code\\BeforeSleeping30m\\testData\\my\\my2.txt"));
        if (deleteIfExists){
    
            System.out.println(" Delete successful ！");
        }
    }
}