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Thread: Mysterious disappearing classes.

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    Default Mysterious disappearing classes.

    So I built this card game program which I've discussed here before. After I worked out the bugs and got it running as a JAR file about 2 months ago, I didn't have anything to do, so I didn't much look at it after that. I moved on to other projects.

    I have 2 computers; a desktop at home which runs Windows XP and a laptop that runs Windows 7. I don't focus very well at home, so I often like to take my laptop to the library and work there, or if I have a class in the morning I'll stick around at school all day. Anyway.. I store all my programming projects in a Dropbox folder to make them easily accessible from the 2 different computers.

    By default, Dropbox locates its folder within a subfolder of the My Documents folder. As you may already know, Windows XP and Windows 7 put the My Documents folder in 2 different places. XP is C:\Documents and Settings\..... and 7 is C:\Users\... This wasn't really a big deal until I started studying PHP. Because PHP requires all code to be run through a web browser and run off some sort of server, I decided I needed to install XAMPP. I wasn't about to start working in some crummy text editor and uploading my code to a web space every single time I made the slightest change.

    Again, since I was working through 2 computers, I decided to use Dropbox. It seems like a no brainer, since XAMPP just installs in a XAMPP folder, and not the traditional C:\Program Files\... environment like most programs. But since the configuration files for XAMPP make references to other folders and files, I knew that the full path name would have to be the same on both computers. Therefore, the differing locations of the Dropbox folders was now a problem.

    The Dropbox client program luckily has a utility for moving the folder easily, which I used, and moved it to C:\Dropbox on both computers. After that, XAMPP was working great on both computers

    tl;dr, enough of the back story

    Now there's a new problem. The movement process meant I had to create a new Workspace in Eclipse, and then import my projects into the new workspace. No problem. I did this pretty painlessly and most everything worked (a database program I've been working with couldn't load the MySQL JDBC driver anymore, but I fixed that). However... one odd problem has come up that I can't seem to figure out.

    The .class files are gone for my HigherNumber program. The bin folder is just gone. All the source code is still there, as are all the .java files. I dunno why. It seems to have happened in the Dropbox folder transition.

    How can I get these .class files back? Is there a way other than starting a new project and doing a copy/paste of all the source code into the new project?


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    Default Re: Mysterious disappearing classes.

    The .class files are created by the compiler. Sounds like you just need to recompile your source to recreate them.

    Eclipse does this automatically by default, and you can set the destination of the created .class files in your project properties. By default it puts your .class files in a folder named bin, which is located next to your src folder. But all of this is customizable, so it's hard to say exactly what the case is for you.

    If you have any problems with your build path or compiler errors, eclipse might not be able to create the .class files. That's another thing to look into.
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    Default Re: Mysterious disappearing classes.

    Hmm... Curious. I couldn't figure out how to compile it. I haven't seen a compile option anywhere in Eclipse. Normally whenever I write up code I click the green triangle that looks like a "Play" button and that runs the code. Now it's just giving me the error Error: Could not find or load main class higherNumber.HigherNumber, I guess because the classes aren't there.

    However, I did find the Clean option under the Project menu, and that seems to have done the trick. Thanks Kevin.

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    Default Re: Mysterious disappearing classes.

    Yeah, the clean option will delete any old .class files and recompile everything for you. Look for a "build automatically" option in that same menu, as well as a "build project" option.
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