How to delete a temporary file in Java

In Java, we can use the NIO Files.delete() or Files.deleteIfExists() to delete a temporary file, it works the same like delete a regular text file.

  // create a temporary file
  Path path = Files.createTempFile(null, ".log");
  // delete
  Files.delete(path);

  // or
  if(Files.deleteIfExists(path)){
    // success
  }else{
    // file does not exist
  }

1. Delete Temporary File – Java NIO

This example uses java.nio to create a temporary file, write a line, and delete it.

package com.mkyong.io.temp;

import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;

public class TempFileDelete1 {

    public static void main(String[] args) {

        try {

            Path temp = Files.createTempFile(null, ".log");
            System.out.println(temp);

            // if file doesn't exist throws NoSuchFileException
            // Files.delete(temp);

            // write a line
            Files.write(temp, "Hello World".getBytes(StandardCharsets.UTF_8));

            // check if file exists before delete
            boolean result = Files.deleteIfExists(temp);
            if (result) {
                System.out.println("File is success delete.");
            } else {
                System.out.println("File doesn't exist.");
            }

        } catch (IOException e) {
            System.err.println("Unable to delete the file!");
            e.printStackTrace();
        }

    }

}

Output

/tmp/16821893865655843803.log
File is success delete.

2. Delete Temporary File – Java IO

This example uses the legacy IO java.io to create a temporary file, and delete it later.

package com.mkyong.io.temp;

import java.io.File;
import java.io.IOException;

public class TempFileDelete2 {

    public static void main(String[] args) {

        try {

            File tempFile = File.createTempFile("abc_", ".log");
            System.out.println(tempFile);

            boolean result = tempFile.delete();
            if (result) {
                System.out.println(tempFile.getName() + " is deleted!");
            } else {
                System.out.println("Sorry, unable to delete the file.");
            }

            // delete when JVM exit normally.
            // tempFile.deleteOnExit();

        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}

The file.deleteOnExit() will delete the temporary file only if "JVM exit normally" uses it with care.

Download Source Code

References

• Legacy File I/O Code
• Files JavaDoc
• How to delete a file in Java