Problem with Java FileReader [duplicate]

问题:

This question already has an answer here:

• FileNotFoundException, the file exists Java [closed] 2 answers

Hello I have this in my code

File file = new File("words.txt");
    Scanner scanFile = new Scanner(new FileReader(file));
    ArrayList<String> words = new ArrayList<String>();

    String theWord;    
    while (scanFile.hasNext()){
        theWord = scanFile.next();
        words.add(theWord);
    }

But for some reason I am getting a

java.io.FileNotFoundException

I have the words.txt file in the same folder as all of my .java files

What am I doing wrong? Thanks!

回答1:

Tip: add this line to your code...

System.out.println(file.getAbsolutePath());

Then compare that path with where your file actually is. The problem should be immediately obvious.

回答2:

The file should reside in the directory from which you execute the application, i.e. the working directory.

回答3:

Generally it's a good idea to package data files with your code, but then using java.io.File to read them is a problem, as it's hard to find them. The solution is to use the getResource() methods in java.lang.ClassLoader to open a stream to a file. That way the ClassLoader looks for your files in the location where your code is stored, wherever that may be.

回答4:

try:

URL url = this.getClass().getResource( "words.txt" );
File file = new File(url.getPath());

回答5:

You haven't specified an absolute path. The path would therefore be treated as a path, relative to the current working directory of the process. Usually this is the directory from where you've launched the Main-Class.

If you're unsure about the location of the working directory, you can print it out using the following snippet:

System.out.println(System.getProperty("user.dir"));

Fixing the problem will require adding the necessary directories in the original path, to locate the file.