non-static method openInputFile(String) cannot be referenced from a static contex java

Question

Here is my code in question:

public File openInputFile(Scanner kb)
{
  if(kb == null)
  {   
     throw new RuntimeException("ERROR! Scanner Not Detected.");
  }
  System.out.print("Enter Name of File: ");
  String fn = kb.nextLine();
  File inf = FileUtil.openInputFile(fn); 
  return inf;
}

I am getting the following error:

FileUtil.java:33: error: non-static method openInputFile(String) cannot be referenced from a static context
      File inf = FileUtil.openInputFile(fn); 
                         ^

Nothing is static, so I'm not sure why I'm getting this error. Can anyone help?

when the method is static you gonna use it like the name of the class.the name of method — Kick Buttowski, Nov 17 '14 at 06:00
Even it is not clear what you try to accomplish by your code. — Kick Buttowski, Nov 17 '14 at 06:00

score 0 · Answer 1 · answered Nov 17 '14 at 06:02

0

File inf = FileUtil.openInputFile(fn); tells the compiler that openInputFile(fn) is static method of class FileUtil because you are trying to make a call to the method from the class name itself. This is why compiler said

FileUtil.java:33: error: non-static method openInputFile(String) cannot be referenced from a static context

So, all you need to do it is, make an object of file util and call the method from that object.

answered Nov 17 '14 at 06:02

Gaurav Gupta

4,586
4
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the op uses the openInputFile method inside the Method openInputFile – Kick Buttowski Nov 17 '14 at 06:03
Param type differs. FileUtil method accept String whereas op's method has argument of type 'Scanner` – Gaurav Gupta Nov 17 '14 at 06:07

score 0 · Answer 2 · answered Nov 17 '14 at 06:02

0

FileUtil class has a method openInputFile() that seems to be non static, hence you have to call it by creating instance of FileUtil

FileUtil fileut= new FileUtil();
fileut.openInputFile();

answered Nov 17 '14 at 06:02

Mustafa sabir

4,130
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the op uses the openInputFile method inside the Method openInputFile – Kick Buttowski Nov 17 '14 at 06:03
Yes But those methods seem to be overridden, since they have different params – Mustafa sabir Nov 17 '14 at 06:04
but it sounds confusing and does not express what programmer tries to accomplish here ?!!!! – Kick Buttowski Nov 17 '14 at 06:06
Hmm exactly, but I think in any case this would work, even if the both the methods, `openInputFile(scanner)` and `openInputFile(String)` are part of the same class (overriden methods). Or the `openInputFile(scanner)` method is present in completely different class. But yes its really unclear what OP is trying to achieve – Mustafa sabir Nov 17 '14 at 06:08
1

@KickButtowski It surely does looks confusing, but different issue. Seems more like design issue rather than compiler error. – Gaurav Gupta Nov 17 '14 at 06:08
@Mustafasabir good point. it seems the op overloded the openInputFile but it is very confusing again :) – Kick Buttowski Nov 17 '14 at 06:10
@GauravGupta I am totally with you :) – Kick Buttowski Nov 17 '14 at 06:10

non-static method openInputFile(String) cannot be referenced from a static contex java

2 Answers2