一次将多个实例记录到控制台-java.util.logging.Logger

Question

Getting Java Logger to echo-return a single message inside console. After multiple JSON objects are successfully loaded.

In my server/client framework, I have multiple defining JSON objects, server-sided. Thus, a java.util.logging.Logger is a helpful informant. If or if not, said JSON files or "objects" were created successful, during the initial bootstrap, loading stage. Messages echo in-console, detailing that. Doing exactly as the Logger object should.

Here, I will give an example from code, reinforcing the need for such a logger running at the levels; Level.INFO & Level.SEVERE .

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Code Sample

This sample is from a class, DefinitionLoader.java . Implementing Runnable, as implied by the apparent run() method.

public abstract void load() throws Throwable;
public abstract String file();

@Override
public void run() {
    try {
        long start = System.currentTimeMillis();
        load();
        long elapsed = System.currentTimeMillis() - start;
        Server.getLogger().log(Level.INFO, "Loaded definitions for: "+file()+". It took "+elapsed+" milliseconds.");
    } catch(Throwable e) {
        e.printStackTrace();
        Server.getLogger().log(Level.SEVERE, "Loaded definitions for: "+file(), e);
    }
}

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Each singular JSON object, is executed to & from memory via load() / file() calls. Necessarily, they are logged.

There's only one problem with mine & Java 8's logging capabilities. Each logging message or indication of a successfully loaded JSON file, is 'spit out' or for better terms, printed to the console. Producing an intrusive amount of information, only furthering any hypothetical issues. I would love for it to just say,

All definitions have been loaded successfully.

a single time, within the console, among other bootstrap linguistics.

Finally,

What are the implications of just housing a System.out property in the run() method instead of just logging it like this? Ideally, logging can do no harm other then when your are bombarded by;

Console Output

INFO: Initializing the Bootstrap...
Feb 23, 2018 10:01:40 PM com.MYPACKAGE.definition.loader.DefinitionLoader run
INFO: Loaded definitions for: ./DIRECTORY/definitions/SOMEJSONFILE.json. It took 344 milliseconds.
Feb 23, 2018 10:01:40 PM com.MYPACKAGE.definition.loader.DefinitionLoader run
INFO: Loaded definitions for: ./DIRECTORY/definitions/SOMEJSONFILE.json. It took 609 milliseconds.
Feb 23, 2018 10:01:40 PM com.MYPACKAGE.definition.loader.DefinitionLoader run
INFO: Loaded definitions for: ./DIRECTORY/definitions/SOMEJSONFILE.json. It took 2 milliseconds.
Feb 23, 2018 10:01:40 PM com.MYPACKAGE.definition.loader.DefinitionLoader run
INFO: Loaded definitions for: ./DIRECTORY/definitions/SOMEJSONFILE.json. It took 32 milliseconds.
Feb 23, 2018 10:01:40 PM com.MYPACKAGE.definition.loader.DefinitionLoader run
INFO: Loaded definitions for: ./DIRECTORY/definitions/SOMEJSONFILE.json. It took 125 milliseconds.
Feb 23, 2018 10:01:40 PM com.MYPACKAGE.definition.loader.DefinitionLoader run
INFO: Loaded definitions for: ./DIRECTORY/definitions/SOMEJSONFILE.json. It took 42 milliseconds.
Feb 23, 2018 10:01:40 PM com.MYPACKAGE.definition.loader.DefinitionLoader run
INFO: Loaded definitions for: ./DIRECTORY/definitions/SOMEJSONFILE.json. It took 47 milliseconds.
Feb 23, 2018 10:01:41 PM com.MYPACKAGE.Server main
INFO: The Bootstrap has been bound, SERVER is now online!

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In conclusion,

I made an attempt at processing the logger through a for loop . Also, I passed a bool parameter using the constructor: log(Level level, String msg, Object[] params) . Finally, to my surprise after taking to the web for answers in dealing with my situation. Any and only clues I could find, provided nothing in relation to the logging spam. Just want to say, thank you to the stranger(s) &/or whoever can & is willing to help!

Answer 1

A possible solution could be a countdown latch. This basically means that each thread is given a mechanism to signal that it has done its job, and the calling thread can wait for all threads to finish.

Here's the example from Java's implementation

 class Driver2 {
   void main() throws InterruptedException {
     CountDownLatch doneSignal = new CountDownLatch(N);
     Executor e = ...

     for (int i = 0; i < N; ++i) // create and start threads
       e.execute(new WorkerRunnable(doneSignal, i));

     doneSignal.await();           // wait for all to finish
   }
 }

 class WorkerRunnable implements Runnable {
   private final CountDownLatch doneSignal;
   WorkerRunnable(CountDownLatch doneSignal) {
      this.doneSignal = doneSignal;
   }
   public void run() {
      try {
        doWork();
        doneSignal.countDown();
      } catch (InterruptedException ex) {} // return;
   }
 }

You could add a log message once the await has finished, and also check that each thread finished successfully (by having them write a result somewhere, or by inspecting a public property on them directly).