Use empty check on buffers

Author: sualeh

schemacrawler-lint/src/main/java/schemacrawler/tools/lint/Linters.java

@@ -88,7 +88,7 @@ public String getLintSummary() {
       }
     }
 
-    if (buffer.length() > 0) {
+    if (!buffer.isEmpty()) {
       buffer.insert(0, "Summary of schema lints:\n");
     }
 

schemacrawler-text/src/main/java/schemacrawler/tools/text/formatter/schema/SchemaTextFormatter.java

@@ -1157,7 +1157,7 @@ private void printTriggers(final Collection<Trigger> triggers) {
             new ArrayList<>(trigger.getEventManipulationTypes());
         if (eventManipulationTypes != null
             && eventManipulationTypes.get(0) != EventManipulationType.unknown) {
-          if (timingBuffer.length() > 0) {
+          if (!timingBuffer.isEmpty()) {
             timingBuffer.append(SPACE);
           }
           for (final EventManipulationType eventManipulationType : eventManipulationTypes) {