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HW Help error **Exception in thread "main" java.lang.NullPointerException** , program runs fine in command line but not eclipse or neat beans [duplicate]

Code:
import java.io.*;
import java.util.Scanner;
public class Driver {
private int colorStrength;
private String color;
public static void main(String[] args) throws IOException {
String line, file = "strength.txt";
File openFile = new File(file);
Scanner inFile = new Scanner(openFile);
while (inFile.hasNext()) {
line = inFile.nextLine();
System.out.println(line);
}
inFile.close();
}
}
This is a small part of a program I am writing for a class (the two private attributes have yet to be used I know) but when I try to run this with the strength.txt file I receive the following errors:
Exception:
Exception in thread "main" java.io.FileNotFoundException: strength.txt (The system cannot find the file specified)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(Unknown Source)
at java.util.Scanner.<init>(Unknown Source)
at Driver.main(Driver.java:14)
If anyone with Eclipse could help me figure this out it would be much appreciated!

You've used a relative file path which is relative to your project execution.
If you'd like to do it that way, simply put the strength.txt file in the base directory of your project. Like so:
Alternatively, you could reference the absolute file path on your system. For example, use:
Windows:
C:/dev/myproject/strength.txt
Mac/Unix:
/Users/username/dev/strength.txt
(or whatever the full path may be) instead.

Do this
System.out.println(openFile.getAbsolutePath());
It will show you where JVM expects to find the file and whether it is the folder you expect as well, Accordingly place the file or give the exact location

Use this to see what file path the system is using to reach the relative path
System.out.print(System.getProperty("user.dir"));
Then make sure that the relative path immediately follows this path.
You can also turn that into a string by doing
String filePath = System.getProperty("user.dir");
and then you can just add that to the beginning of the filepath like so,
ImageIcon imageIconRefVar = new ImageIcon(filePath + "/imagepathname");
I found this solved the issue for me when I used it in the path (which seemed odd since that should be the location it is in, but it worked)

You've used a relative file path which is relative to your project execution.
If this works for you, you can change the execution directory from the project root to the binary directory by:
"Run" -> "Run configurations"
In the "Arguments" tab, find "working directory" settings.
Switch from "Default" to "Other".
Click the "Workspace" button and select the project in pop-up window then click "OK"; this will bring you something like $(workspace_loc:proj-1).
Append "/bin" to the end of it; save the configuration.
I need this instead of simply putting files in project root directory when I am doing assignment and the professor requires specific file hierarchy; in addition, this is more portable than absolute path.

Inside the base directory create a folder, name it "res". Place your file inside "res" folder.
use String file = ".\\res\\strength.txt"; to reference the location of your file.
You should use a resource folder to store all the files you use in your program (a good practice).
And make a refrence of that file from your root directory. So the file is present within the package.

FileInputStream throws FileNotFoundException

This code throws FileNotFoundException.
Edit: As requested I have included the full StackTrace.
import java.io.FileInputStream;
import java.io.InputStream;
public class ReadFile{
public static void main(String[] args){
InputStream inputstream = new FileInputStream("C:\\file.txt");
}
}
The file "file.txt" is at that location though. I would like to post a screenshot of this as requested, but I can't because I need at least 10 reputation points.

If you are 100% certain that the file exists and you're still getting a FileNotFoundException, than most likely your user or the user running Java has no permission to access this file (since I am using German Windows the dialog is in German, but as you can see "Benutzer" (which is Users) have a denied right to read and execute the file a.txt:
This however, results in a a FileNotFoundException with a localized error message returned :
Exception in thread "main" java.io.FileNotFoundException: C:\a.txt (Zugriff verweigert)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(FileInputStream.java:131)
at java.io.FileInputStream.<init>(FileInputStream.java:87)
at Threadstuff.main(Threadstuff.java:50)
Zugriff verweigert means "access denied". If that isn't the problem either, I guess you should post your full StackTrace.
The other option I mentioned in my comment is an explorer option ("View" -> "Options") in the Folder and Search options -> View:
(roughly translates to "Hide extensions for known extensions")
If this is enabled, the filenames in the explorer are losing their extensions in the view. Meaning that they are shown as "file" instead of "file.txt" - which sometimes leads to the mistake of creating a "file.txt.txt" when renaming a file. And is/was also often used to trick users into thinking they were open a different kind of file (.pdf.exe) - mostly used by bad guys.

Is this really the full Filepath? Better check that one.
Also I'd recommend putting files that are to be read by your program e.g. Textfiles, Images and such into the classpath of your project so when you pack and export it the file paths are not obstructed by being on somebody else's PC where that file does not exist on that path and so on.
This answer suggest you transform the Path of the file to a java conform URL path.

Try the below one.
InputStream inputstream = new FileInputStream("C:"+File.separator+"file.txt");
A better approach would be
File file = new File("C:"+File.separator+"file.txt");
if(file.exists()) {
//Read the file
}
else {
System.out.println("File does not exist);
}
To ensure whether file exists or not in windows, press windows button + r and then paste the file path you have mentioned and after that press enter key. If file is in that location, a notepad with file contents will be opened.

File default location

Why the program search the file:
File FILE_PATH = new File("‪‪C:\\Users\\home\\Desktop\\DbWord.txt");
System.out.println(FILE_PATH.exists());
System.out.println(FILE_PATH.getAbsoluteFile());
FileInputStream fIn = new FileInputStream(FILE_PATH);
Scanner reader = new Scanner(fIn);
at: C:\Users\home\Documents\NetBeansProjects\MyDatabase\‪‪C:\Users\home\Desktop\DbWord.txt
How can i counteract the default location?
If something in this post not good, please tell me and no negative vote.
Thanks!
why negative votes??????????????? whats your problems??????????

Please double check your error details. You might have seen something like the below error. Actually the program is not searching for the file "C:\Users\home\Documents\NetBeansProjects\MyDatabase\‪‪C:\Users\home\Desktop\DbWord.txt", it is trying to locate the file "C:\Users\home\Desktop\DbWord.txt" which does not exists in your machine. You are seeing "C:\Users\home\Documents\NetBeansProjects\MyDatabase\‪‪C:\Users\home\Desktop\DbWord.txt" along with the error because you have already used System.out.println(FILE_PATH.getAbsoluteFile()); statement in your code.
false
Exception in thread "main" java.io.FileNotFoundException: ‪‪C:\Users\home\Desktop\DbWord.txt (The filename, directory name, or volume label syntax is incorrect)
at java.io.FileInputStream.open0(Native Method)
at java.io.FileInputStream.open(FileInputStream.java:195)
at java.io.FileInputStream.<init>(FileInputStream.java:138)
C:\Users\home\Documents\NetBeansProjects\MyDatabase\‪‪C:\Users\home\Desktop\DbWord.txt
at com.stackoverflow.answer.SimpleFileHelper.main(SimpleFileHelper.java:17)
Hope you are clear now.
There are three main chances where a FileNotFoundException may be thrown.
The named file does not exist.
The named file is actually a directory not file.
The named file cannot be opened for reading due to some reason.
The first two reasons are unlikely based on your description, please check the third point using file.canRead() method.
If the test above returns true, I would suspect the following:
You might have forgotten to explicitly throw or catch the potential exception (i.e., FileNotFoundExcetion). If you work in an IDE, you should have got some complaint from the compiler. But I suspect you didn't run your code in such an IDE.
Try the following code and see if the exception would be gone:
package com.stackoverflow.answer;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class SimpleFileHelper {
public static void main(String[] args) throws FileNotFoundException {
File FILE_PATH = new File("C:/Users/home/Desktop/DbWord.txt");
System.out.println(FILE_PATH.exists());
System.out.println(FILE_PATH.getAbsoluteFile());
FileInputStream fIn = new FileInputStream(FILE_PATH);
Scanner reader = new Scanner(fIn);
}
}

Program that cannot acess input from a file

I have a program that scans a file and then closes the file.
import java.util.*;
import java.io.*;
public class FileTester{
public static void main(String[] args) throws IOException {
File test = new File("MyDatta.in.txt");
Scanner sf = new Scanner(test);
sf.close();
}
}
When I run the program I get an error message like this:
Exception in thread "main" java.io.FileNotFoundException: MyDatta.in.txt (No such file or directory)
at java.io.FileInputStream.open(Native Method)
at java.io.FileInputStream.<init>(FileInputStream.java:120)
at java.util.Scanner.<init>(Scanner.java:636)
at FileTester.main(FileTester.java:6)
I have a mac that runs on Mac OS. I have reason to believe it has to do with the pathway to my file which is in documents. I know in windows one would use C:\folder name\file to scan it but I just don't know with Mac and I cannot find it anywhere

From Java documentation for FileInputStream: "If the named file does not exist, is a directory rather than a regular file, or for some other reason cannot be opened for reading then a FileNotFoundException is thrown."
Maybe file is used by another program?

You should put this as the file path:
~/Documents/MyDatta.in.txt
to tell java that your file is in documents. The ~ is your home folder.

How do I access a cd drive using java?

How can I access the CD Rom drive (in my case, F:) from Java? I don't mind platform specific code. I am using Windows 8. I have the following code but get AccessDenied.
public static void main(String args[]) throws IOException {
File cd = new File( "f:\\lang" );
System.out.println(cd.canRead());
RandomAccessFile rawAccess = new RandomAccessFile( cd, "r" );
rawAccess.close();
}
The 3 trues are checking for cd.canRead, cd.canWrite, cd.canExecute.
true
true
true
Exception in thread "main" java.io.FileNotFoundException: f:\lang (Access is denied) at java.io.RandomAccessFile.open(Native Method)
at java.io.RandomAccessFile.<init>(Unknown Source) at myapp.main(myapp.java:16)

RandomAccessFile provides access to Files not Directories.
The FileNotFound is thrown, because there is no file, just a directory.
http://docs.oracle.com/javase/6/docs/api/java/io/RandomAccessFile.html#RandomAccessFile(java.io.File, java.lang.String)

I see my error now. I'm trying to use the Java File object when what I really want is raw data from the disc. I was giving a directory and trying to open it like a file causing the error seen in the original post. It worked once I changed the path to a specific file.
I will create a new question that is more clear about what I want. Thank you.