Home > Java > JavaBase > body text

Java implements a method to determine whether a file file exists

王林
Release: 2019-11-30 09:40:03
Original
4617 people have browsed it

Java implements a method to determine whether a file file exists

This example shows how to check for the existence of a file using the file.exists() method of the File class.

package com.yiibai;
import java.io.File;
public class FileExistence {
    public static void main(String[] args) {
        File file = new File("F:/worksp/javaexamples/java_files/myfile.txt");
        System.out.println(file.exists());
    }
}
Copy after login

Executing the above example code will produce the following results:

true
Copy after login
Copy after login

Recommended related video tutorials: java online learning

Example 2:

The following is another example of determining the existence or non-existence of a file in java

package com.yiibai;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintWriter;
import java.nio.file.FileAlreadyExistsException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
public class FileExistence2 {
   public static void main(String[] args) throws IOException {
      File f = new File(System.getProperty("user.dir")+"/folder/file.txt");
      System.out.println(f.exists());

      if(!f.getParentFile().exists()){
         f.getParentFile().mkdirs();
      } 
      if(!f.exists()){
         try {
            f.createNewFile();
         } catch (Exception e) {
            e.printStackTrace();
         } 
      } 
      try {
         File dir = new File(f.getParentFile(), f.getName());
         PrintWriter pWriter = new PrintWriter(dir);
         pWriter.print("writing anything...");
         pWriter.close();
      } catch (FileNotFoundException e) {
         e.printStackTrace();
      } 
   }
}
Copy after login

Executing the above example code will produce the following results-

false
Copy after login

The results returned by running it again Recommended for:

true
Copy after login
Copy after login

More related articles and tutorials: java introductory tutorial

The above is the detailed content of Java implements a method to determine whether a file file exists. For more information, please follow other related articles on the PHP Chinese website!

Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template