Use Method.getParameterCount() where possible

Author: cowtowncoder

release-notes/CREDITS-2.x

@@ -1419,3 +1419,7 @@ Krishna Ghimire (Krishnaghimir@github)
   * Reported #3369: Deserialization ignores other Object fields when Object or Array
   value used for enum
   (2.13.2)
+
+Christoph Dreis (dreis2211@github)
+  * Suggested #3293: Use Method.getParameterCount() where possible
+  (2.13.2)

release-notes/VERSION-2.x

@@ -6,6 +6,8 @@ Project: jackson-databind
 
 2.13.2 (not yet released)
 
+#3293: Use Method.getParameterCount() where possible
+ (suggested by Christoph D)
 #3344: `Set.of()` (Java 9) cannot be deserialized with polymorphic handling
  (reported by Sam K)
 #3368: `SnakeCaseStrategy` causes unexpected `MismatchedInputException` during

src/main/java/com/fasterxml/jackson/databind/deser/BeanDeserializerBase.java

@@ -961,8 +961,8 @@ protected SettableBeanProperty _resolveInnerClassValuedProperty(DeserializationC
                 // and is inner class of the bean class...
                 if ((enclosing != null) && (enclosing == _beanType.getRawClass())) {
                     for (Constructor<?> ctor : valueClass.getConstructors()) {
-                        Class<?>[] paramTypes = ctor.getParameterTypes();
-                        if (paramTypes.length == 1) {
+                        if (ctor.getParameterCount() == 1) {
+                            Class<?>[] paramTypes = ctor.getParameterTypes();
                             if (enclosing.equals(paramTypes[0])) {
                                 if (ctxt.canOverrideAccessModifiers()) {
                                     ClassUtil.checkAndFixAccess(ctor, ctxt.isEnabled(MapperFeature.OVERRIDE_PUBLIC_ACCESS_MODIFIERS));

src/main/java/com/fasterxml/jackson/databind/introspect/AnnotatedConstructor.java

@@ -169,8 +169,7 @@ public Object getValue(Object pojo)
 
     @Override
     public String toString() {
-        // 03-Nov-2020 ckozak: This can use _constructor.getParameterCount() once java 8 is required.
-        final int argCount = _constructor.getParameterTypes().length;
+        final int argCount = _constructor.getParameterCount();
         return String.format("[constructor for %s (%d arg%s), annotations: %s",
                 ClassUtil.nameOf(_constructor.getDeclaringClass()), argCount,
                 (argCount == 1) ? "" : "s", _annotations);

src/main/java/com/fasterxml/jackson/databind/introspect/AnnotatedCreatorCollector.java

@@ -352,7 +352,7 @@ protected AnnotatedConstructor constructNonDefaultConstructor(ClassUtil.Ctor cto
     protected AnnotatedMethod constructFactoryCreator(Method m,
             TypeResolutionContext typeResCtxt, Method mixin)
     {
-        final int paramCount = m.getParameterTypes().length;
+        final int paramCount = m.getParameterCount();
         if (_intr == null) { // when annotation processing is disabled
             return new AnnotatedMethod(typeResCtxt, m, _emptyAnnotationMap(),
                     _emptyAnnotationMaps(paramCount));

src/main/java/com/fasterxml/jackson/databind/introspect/AnnotatedMethodCollector.java

@@ -184,8 +184,7 @@ private static boolean _isIncludableMemberMethod(Method m)
         }
         // also, for now we have no use for methods with more than 2 arguments:
         // (2 argument methods for "any setter", fwtw)
-        int pcount = m.getParameterTypes().length;
-        return (pcount <= 2);
+        return (m.getParameterCount() <= 2);
     }
 
     private final static class MethodBuilder {

src/main/java/com/fasterxml/jackson/databind/util/ClassUtil.java

@@ -1448,7 +1448,7 @@ public Constructor<?> getConstructor() {
         public int getParamCount() {
             int c = _paramCount;
             if (c < 0) {
-                c = _ctor.getParameterTypes().length;
+                c = _ctor.getParameterCount();
                 _paramCount = c;
             }
             return c;