how to globalize method parameter in java?

I've created method in which I have 2 params.

Here's short description:

public static final Logger log = LoggerFactory.getLogger(MyClass.class);

public String executeRequest(final String content, final String appId) {
     log.info("launching request with appID[{}]", appId);
     /*some code here*/
     .................
     .................
     return content;
}

The parameter appId is only used in logs. I want to globalize it.
The reason why is that I dont want to put that param in every method I make so how should I do it smartly? or is it even a good idea to do it like that?

basically I would do it like this:

public static final Logger log = LoggerFactory.getLogger(MyClass.class);

public static String applicationId;

public String executeRequest(final String content, final String appId) {

     applicationId = appId;

     log.info("launching request with appID[{}]", applicationId);
     /*some code here*/
     .................
     .................
     return content;
}

So my question would be. From the architect point of view is it ok to do it like this? Should I even do it like that?

As far as I understand your problem:

• Every invocation of executeRequest(final String content, final String appId) brings its own appId, I guess it somehow identifies the caller.
• There can be multiple requests running in parallel, in individual threads.
• When logging, you want the log to contain this appId that caused the request.
• You don't want to pass this appId down the complete call stack to every method where logging might occur.
• There are no recursive calls of executeRequest(final String content, final String appId), at least none where the appId differs from the initial one.

I agree that in such a case the appId is not worth being added to lots of method signatures, as it's only used for logging and has nothing to do with the regular processing.

Then I'd use a ThreadLocal<String>.

public static final Logger log = LoggerFactory.getLogger(MyClass.class);

public static final ThreadLocal<String> appIdHolder = new ThreadLocal<>();

public String executeRequest(final String content, final String appId) {
     appIdHolder.set(appId);
     log.info("launching request with appID[{}]", appIdHolder.get());
     /*some code here*/
     .................
     .................
     return content;
}

ThreadLocal gives you a kind of global variable, with the additional feature that it holds one value per thread. If multiple requests are running in parallel, they won't interfere, as they run on different threads, and so they get individual values.

If you don't have recursive calls of executeRequest(), you might consider adding appIdHolder.remove() at the end of the method body to free the thread-specific resource if you think that's necessary. But don't do it with recursive calls, because then some nested call would clear the variable, and the remaining code would lack a valid appId. ThreadLocal does not support stack-like pushing and popping of values.

Since you tell that value can change for different process you just use properties

public class Constants {

   public static final String APP_ID = System.getProperty("APP_ID");

}

and run you jar like java -jar myjar.jar -DAPP_ID=some value. Also Eclipse & IDEA allows you to pass parameters via -D as well