在Java中，当我们使用函数'FileReader（String fileName）'时，应该在哪里保存文件fileName？

Question

In my program I have used the function FileReader(String fileName) to read a file. This file is kept at fileName is holding a string setup.ini . I have kept this file in the same folder from where I am compiling my java program but even after I have removed the file from this folder I am not getting any Exception of File not found. So I wonder does the compiler take the file from some other location?

Please see the code below:

public class ReadINI
{
    public static void main(String args[]) throws IOException
    {
        String s = getParameter("bin","setup.ini");
        System.out.println("Result   " + s);
    }

    public static String getParameter(String inputValue, String fileName)
    {
        try
        {
            BufferedReader myInput = new BufferedReader(new FileReader(fileName));
            try 
            {

                try {
                        String fileLine;
                        fileLine = myInput.readLine();

                        do
                        {
                            String stringArray[] = fileLine.split("=");
                            if (inputValue.equals(stringArray[0]))
                            return stringArray[1];
                        }while ((fileLine = myInput.readLine()) != null); 
                    }
                    catch (Exception e)
                    {
                        System.err.println("Error1: " + e);
                    }
             } // end try
             catch (Exception e)
             {
                 System.err.println("Error2: " + e);
             }

         } // end try
         catch (Exception e)
         {
             System.err.println("failed to open file setup.ini");
             System.err.println("Error3: " + e);
         }
         return "Not Found";
     }

}

Answer 1

The compiler doesn't search for your file anywhere. The file is searched for at run time, not at compile time. If you give a relative path, the file will be searched for in the directory where you run the program.

Answer 2

    the file should be right inside your project outside src directory , 
    the file should be in the same folder where src folder is present

    |--MyProject
       |--src
       |--youFile.txt

or you can give full path to the file which is located anywhere on the disk
String fileName = "c:/folder1/folder2/yourFile.txt";

Answer 3

Any request to open a file inside a java application makes the JVM start its search from the CLASSPATH of that particular java class. So, when you place the file you want to open in code in the CLASSPATH - basically the folder in which the .java file (and hence the compiled .class file) resides. Elaborating, if your file someFile.txt is to be accessed by SomeClass which is residing in package org.pack1.pack2 , that someFile.txt should be present in the folder \\org\\pack1\\pack2\\

Use of absolute paths to access a file inside an application is discouraged as it would dent the portability of that application.