Log4j

[Ana Alamo <aa...@bilbomatica.es>]

Excuse me, for example i have this java's program, i execute tis and any log sentence was show 
because    this sentences ignores all >>>  cat.getDefaultHierarchy().disableAll();
but for example i want to see what kind of error occurs or i want to see the logs sentence.
What is the meanning of this:

"In cases of problems whit an application, tecnical support can re-enable logging by setting
 the log2.disableOverride system property without changing the binary al client's site"

How it´s possible to do that change, can you explain me?



 i didn´t understand how can 
package com.foo.MyApp1;
import org.apache.log4j.*;
import com.foo.Bar;

public class MyApp2 {
  static Category cat = Category.getInstance(MyApp2.class);
  public MyApp2() {
  }

  public static void main(String[] args) throws Exception
  {
      Category root = Category.getRoot();
      Layout layout = new PatternLayout("%5p [%t] (%F:%L) %-5p %c{2} %x - %m%n");
      root.addAppender(new ConsoleAppender(layout, ConsoleAppender.SYSTEM_OUT));
      root.addAppender(new FileAppender(layout, "ejemplo.log"));
      Category barcat = Category.getInstance("com.foo.Bar");

      barcat.setPriority(Priority.INFO);
      cat.setPriority(Priority.INFO);

      cat.getDefaultHierarchy().disableAll();

      cat.info("la clase com.foo.Bar    tiene definido como Prioridad -> "  + barcat.getPriority());
      cat.info("la clase com.foo.MyApp1 tiene definido como Prioridad -> "  + cat.getPriority());


//      cat.setPriority(Priority.WARN);
      int i=1;
      cat.debug("Mensaje Nº" + (i++));
      cat.fatal("Mensaje Nº"  + (i++) + " --> se va a ver porque es FATAL>=INFO");
      barcat.info("Mensaje Nº" + (i++) + "--> se va a ver porque es INFO>=INFO");
      barcat.warn("Mensaje Nº" + (i++) + "--> se va a ver porque es WARN>=INFO");

      try {
          cat.info(" divisón entre cero");
          int inNumero = 10/0;
          cat.info("resultado de la division ->" + inNumero);
      } catch (Exception ex) {
          cat.error(ex.getMessage());
      }

  }
}