为什么文件相关的东西不起作用？ (爪哇)

Question

Im currently writing a program which involves creating a Folder and a File within this Folder. The first version worked, after that i decided to create a new project to give the code a clear form. Now, suddenly the class creating the Files wont work anymore. I switched devices with the second project.

package com.company;

import java.io.*;

public class File {
    File folder1 = new File("Data");
    File file1 = new File("Data/MonData.txt"); 

    //For both "Data" and "Data/MonData.txt it says 
    //"Expected 0 arguments but found 1"

    public void DataText() {
        if(folder1.exists()) {         //exists = cant
        }                              //resolve method
        else {
            folder1.mkdirs();          //mkdirs = cant
        }                              //resolve method
        if(file1.exists()) {           //exists = cant
        }                              //resolve method
        else {
            try {
                file1.createNewFile(); //createNewFile = cant 
            }                          //resolve method
            catch(IOException e) {
                e.printStackTrace();
            }
        }
    }
}

Answer 1

You should name your class in a different way. Naming your class File let java use it instead of java.io.File, so the method exists (and so the others) is not found because not in your class.

Answer 2

Your class name & importing class has same name File , So compiler check for your File class not java.io.File one which he should.

In case two class had same name, use java.io.File & your.File instead of File only

Answer 3

Both the classes of yours have the same name. Try naming the class File to java.io.File . It should work fine

Answer 4

You can use fully qualified name

java.io.File folder1 = new java.io.File("Data");
java.io.File file1 = new java.io.File("Data/MonData.txt");