Working with scanner which can't find my file

Question

Hi, all:
I'm working with the Scanner class for the first time, and I'm trying to go through the tutorial. I'm using Eclipse. When I try to access the file called "xanadu.txt" when running the application ScanXan, I'm throwing a file not found exception. I have the file xanadu.txt in the same location as the class file, and for good measure I tried to explicitly specify where the file was when accessing it. Apparently one can't do that. What am I doing wrong?

Answer 1

Yes, the tutorial is assuming the text file is in the same directory as the class file. But how does your program know which directory that is? It looks up the current directory, which is stored in the system properties under the key "user.dir" when the JVM starts up. It's actually the directory from which java.exe was executed, but if the class you're running is in the default package (as yours is), the class file has to be in the same directory.
However, IDE's tend to create their own environments in order to facilitate debugging, profiling, etc. They pretty much ignore the PATH and CLASSPATH settings in your OS--in fact, they usually use their own compilers. As a result, you can't make any assumptions about the current directory.
I'm not saying the IDE definitely is causing the problem, just that it muddies the water. Also, it can be difficult for neophytes to keep Java knowledge separate from IDE knowledge. There's so much to learn in both areas, it's best to get a good grounding in Java before you start learning the IDE.
@Farmor, the {color:000080}try{color} block is only there so they can add the {color:000080}finally{color} block, which makes sure the stream gets closed; the exception is handled by the {color:000080}throws{color} clause in the method declaration.