Revert "@ExceptionHandler methods logs at DEBUG level again"

This reverts commit 162112.

Instead we'll go for a bigger rollback of the change from SPR-17178 so
that only DefaultHandlerExceptionResolver does warn logging by default.

Issue: SPR-17388

spring-webmvc/src/main/java/org/springframework/web/servlet/handler/AbstractHandlerExceptionResolver.java

@@ -135,18 +135,11 @@ public ModelAndView resolveException(
 			prepareResponse(ex, response);
 			ModelAndView result = doResolveException(request, response, handler, ex);
 			if (result != null) {
-				// Print warn or debug message when warn logger is not enabled...
-				if (this.warnLogger == null || !this.warnLogger.isWarnEnabled()) {
-					if (!useWarnLevelWhenWarnLoggerNotEnabled()) {
-						if (logger.isDebugEnabled()) {
-							logger.debug("Resolved [" + ex + "]" + (result.isEmpty() ? "" : " to " + result));
-						}
-					}
-					else if (logger.isWarnEnabled()) {
-						logger.warn("Resolved [" + ex + "]" + (result.isEmpty() ? "" : " to " + result));
-					}
+				// Print warn message when warn logger is not enabled...
+				if (logger.isWarnEnabled() && (this.warnLogger == null || !this.warnLogger.isWarnEnabled())) {
+					logger.warn("Resolved [" + ex + "]" + (result.isEmpty() ? "" : " to " + result));
 				}
-				// Log with warnLogger (requires explicit config)
+				// warnLogger with full stack trace (requires explicit config)
 				logException(ex, request);
 			}
 			return result;
@@ -186,16 +179,6 @@ protected boolean shouldApplyTo(HttpServletRequest request, @Nullable Object han
 		return (this.mappedHandlers == null && this.mappedHandlerClasses == null);
 	}
 
-	/**
-	 * Whether to log warn level messages (return value "true") or debug level
-	 * messages (return value "false") through the regular class logger when
-	 * {@link #setWarnLogCategory warn logging} is not activated.
-	 * <p>By default returns "true".
-	 */
-	protected boolean useWarnLevelWhenWarnLoggerNotEnabled() {
-		return true;
-	}
-
 	/**
 	 * Log the given exception at warn level, provided that warn logging has been
 	 * activated through the {@link #setWarnLogCategory "warnLogCategory"} property.

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/ExceptionHandlerExceptionResolver.java

@@ -491,10 +491,4 @@ protected ServletInvocableHandlerMethod getExceptionHandlerMethod(
 		return null;
 	}
 
-	@Override
-	protected boolean useWarnLevelWhenWarnLoggerNotEnabled() {
-		// Use DEBUG level
-		return false;
-	}
-
 }