Non-static variable filepath cannot be referenced from a static context

Question

I have a simple Java program as follows:

public class HelloWorldPrinter {
    String filepath;

    public void setPath(String path){
        this.filepath = path;
    }

    public static void main(String[] args) throws PrintException, IOException {
        FileInputStream in = new FileInputStream(new File(filepath));
    }
}

I am getting the following error:

HelloWorldPrinter.java:40: error: non-static variable filepath cannot be referenced from a static context

FileInputStream in = new FileInputStream(new File(filepath));

How can I fix this?

Answer 1

One option is to create an instance of HelloWorldPrinter :

public static void main(String[] args) throws PrintException, IOException {
    HelloWorldPrinter printer = new HelloWorldPrinter();
    printer.setPath("path/to/file");

    FileInputStream in = new FileInputStream(new File(printer.getPath()));
}

Answer 2

you can never access non static field inside static field.

because static field does not need object, and non-static does , so static field will never know the state of non-static field.

so you have two option rather make your field static , or create an object before accessing it .

 HelloWorldPrinter obj= new HelloWorldPrinter();
 FileInputStream in = new FileInputStream(new File(obj.getPath()));