log4j动态日志级别调整

//System.out.println("UpdateParents called for " + name);

    //if name = "w.x.y.z", loop thourgh "w.x.y", "w.x" and "w", but not "w.x.y.z"
    for(int i = name.lastIndexOf('.', length-1); i >= 0;
                                     i = name.lastIndexOf('.', i-1))  {
      String substr = name.substring(0, i);

      //System.out.println("Updating parent : " + substr);
      CategoryKey key = new CategoryKey(substr); //simple constructor
      Object o =ht.get(key);
      //Create a provision node for a future parent.
      if(o == null) {
    //System.out.println("No parent "+substr+" found. Creating ProvisionNode.");
    ProvisionNode pn = newProvisionNode(cat);
    ht.put(key, pn);
      } else if(o instanceofCategory) {
    parentFound = true;
    cat.parent =(Category) o;
    //System.out.println("Linking " + cat.name + " -> " + ((Category) o).name);
    break; //no need to update the ancestors of the closest ancestor
      } else if(o instanceofProvisionNode) {
    ((ProvisionNode) o).addElement(cat);
      } else{
    Exception e = new IllegalStateException("unexpected object type " +o.getClass() + " in ht.");
    e.printStackTrace();
      }
    }

for(Category c = this; c != null; c=c.parent) {
      if(c.level != null)
    returnc.level;
    }