How to get a folder path dynamically?

Question

I have a Business folder(e:\\Business) in this folder I have compiled file .I want use this folder in my main program .My main Program is in the Main folder(e:\\ProjectFile\\Main) .

I want get the path of Business folder dynamically .I use this statment but didn't work :

String loadedClassPath = System.getProperty("user.dir")+System.getProperty("file.separator")+"Business";

            File operatorFile = new File(loadedClassPath);
            URL operatorFilePath = operatorFile.toURL();          
            URL[] operatorFilePaths = new URL[]{operatorFilePath};
            ClassLoader operatorsClassLoader = new URLClassLoader(operatorFilePaths);
            Class[] operatorClass = new Class[]{ operatorsClassLoader.loadClass("Plus"), operatorsClassLoader.loadClass("Minus"),operatorsClassLoader.loadClass("Multiply") , operatorsClassLoader.loadClass("Divide") }; 

I think this part is not correct :

String loadedClassPath = System.getProperty("user.dir")+System.getProperty("file.separator")+"Business";

Can anyone help me?

Answer 1

Since "e:\\Business" is entirely unrelated to

• the location of your Java code
• your home directory (user.dir)
• any other well-know Windows or Java directory

you have to tell the program where/what it is.

Some options are:

1. Hard-code in Java program. Not good
2. Pass as argument to main .
3. Store in a property file that is located in one of the directories mentioned above.

There are likely more options, but option 3 is very common, option 2 is less common but might be better choice depending on circumstances, and option 1 is highly discouraged.

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Note: When constructing a path/file name, use new File(parent, child) , or better yet, use the newer Paths.get(first, more, ...) .
"Newer" refers to Java 7, meaning since July 28, 2011, so not really that new any more.