CODEWITHSUNDEEP
java
marc esher
marc esher

Reputation: 4921

How do you get file path for file when user directory changes?

I have a java app, and the log4j.properties file is in src/com/my/path/props. On compile, it's copied into classes/com/my/path/props

The file is loaded via PropertyConfigurator.configureAndWatch(user.dir + "/classes/com/my/path/props/log4j.properties").

This all works fine normally, though it's not ideal because of using user.dir (but I do not know another way to reference a file relative to the "application's start directory"). The problem manifests when trying to run this application using an NT Service wrapper. When done this way, the user.dir changes from the application's root dir to wherever the NTService wrapper's exe file is.

My question is: What's the appropriate way to get a the String file path representation of the log4j.properties file in my classes/com/my/path/props/ directory? I realize this would completely break down if the props file were in a jar; but in this case, it's not and is simply a file on the file system.

I've tried new File(this.getClass().getClassLoader().getResource("com/my/path/props/log4j.properties").getURI()).getAbsolutePath(), but that fails because on production, the path to the file is actually a UNC path and consequently throws a "URI has an authority component" exception.

How do other people deal with this problem?

Thanks.

Upvotes: 0

Views: 820

Answers (2)

marc esher
marc esher

Reputation: 4921

I took singleshot's advice and kept the properties files out of src and instead in a separate directory which I added to the classpath. In retrospect, this was indeed boneheaded to have configured it the way I did originally.

From there, my problem was getting a File from a URL. I ended up finding what I needed in Commons IO FileUtils, with its toFile(URL) method.

The code ended up looking like this:

private URL maintenanceConfigPath = this.getClass().getClassLoader().getResource("MaintenanceConfig.properties");
....
File f = FileUtils.toFile(maintenanceConfigPath);
....

Again, thanks to all for your feedback and for pointing me down a path that got me towards an answer

Upvotes: 0

SingleShot
SingleShot

Reputation: 19131

OK. So... you asked how other people deal with this problem. First, they do not leave it up to Eclipse for where files get placed. They choose where they want them, how they want to access them, and then have their build tool (which unless they are just playing around, should not be an IDE like Eclipse, but rather a dedicated build tool like Maven or Ant) where to place it.

The choice of where you want the file depends on what you want to do with it. If its simply a config file that will never be edited at runtime, you typically place it inside your JAR (which is another practice - applications are placed in one or more JARs, WARs, or EARs, not a classes directory). If the file is to be edited at runtime, which from your "watching" it appears to be the case, you typically put it in a config directory outside your JAR.

How you access it (from the filepath or the classpath) is another choice. Where possible, I favor accessing files from the classpath because it is more portable - and when in a JAR, pretty much required. If that doesn't make sense in your case, then choose a path other than "user.dir" if that is changing when you deploy. You can hard-code it, use an environment variable, a property, a config file, a command line argument, etc. to set the actual path.

Always choose where things go and how you access them. Don't let your tools choose for you. It will make your life easier :-)

Upvotes: 1

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