code: public void init() {
          // load the filter mappings (copy of the list in case add is called while we iterate)
          List fMappings = new ArrayList(webAppConfig.getFilterMappings());
  
          // if the list isn't empty, show that this web app has filters
          if (!fMappings.isEmpty()) {
              if (com.ibm.ejs.ras.TraceComponent.isAnyTracingEnabled() && logger.isLoggable(Level.FINE))
                  logger.logp(Level.FINE, CLASS_NAME, "init", "filter mappings at init time ->" + fMappings);
  
              _filtersDefined = true;
  
              // add the filter mappings to the uri or servlet mapping lists
              Iterator iter = fMappings.iterator();
  
              while (iter.hasNext()) {
                  FilterMapping fMapping = (FilterMapping) iter.next();
  
                  addFilterMapping(fMapping);
  
                  //PK86553 - start
                  if (WCCustomProperties.INVOKE_FILTER_INIT_AT_START_UP){
                      String filterName = fMapping.getFilterConfig().getFilterName();
                      if (_filterWrappers.get(filterName) == null){
                          if (com.ibm.ejs.ras.TraceComponent.isAnyTracingEnabled()&&logger.isLoggable (Level.FINE))
                              logger.logp(Level.FINE, CLASS_NAME,"init", "load filter init at startup, filter ->"+ filterName);
                          try{
                              loadFilter(filterName);
                          }
                          catch (Throwable th) {
                              //logger.logp(Level.FINE, CLASS_NAME, "init", "Can not initialize filter ["+filterName+"] at startup.");//596191
                              LoggerHelper.logParamsAndException(logger, Level.SEVERE, CLASS_NAME,"init", "init.exception.thrown.by.filter.at.startup", new Object[]{filterName} , th );
  
                          }
                      }
                  }
                  //PK86553 - end
              }
          } else if (com.ibm.ejs.ras.TraceComponent.isAnyTracingEnabled() && logger.isLoggable(Level.FINE)) {
              logger.logp(Level.FINE, CLASS_NAME, "init", "no filter mappings at init time");
          }
  
      }
docs: Initialize the manager and see if any filters should be preloaded