DATACMNS-1673 - Polishing.

Convert instance field to constant. Use parameter count for iteration instead of cloning the parameter array.

Original pull request: #426.

src/main/java/org/springframework/data/repository/query/Parameters.java

@@ -47,7 +47,8 @@ public abstract class Parameters<S extends Parameters<S, T>, T extends Parameter
 			"Either use @%s on all parameters except %s and %s typed once, or none at all!", Param.class.getSimpleName(),
 			Pageable.class.getSimpleName(), Sort.class.getSimpleName());
 
-	private final ParameterNameDiscoverer discoverer = new DefaultParameterNameDiscoverer();
+	private static final ParameterNameDiscoverer PARAMETER_NAME_DISCOVERER = new DefaultParameterNameDiscoverer();
+
 	private final int pageableIndex;
 	private final int sortIndex;
 	private final List<T> parameters;
@@ -63,18 +64,18 @@ public abstract class Parameters<S extends Parameters<S, T>, T extends Parameter
 
 		Assert.notNull(method, "Method must not be null!");
 
-		Class<?>[] types = method.getParameterTypes();
+		int parameterCount = method.getParameterCount();
 
-		this.parameters = new ArrayList<>(types.length);
+		this.parameters = new ArrayList<>(parameterCount);
 		this.dynamicProjectionIndex = -1;
 
 		int pageableIndex = -1;
 		int sortIndex = -1;
 
-		for (int i = 0; i < types.length; i++) {
+		for (int i = 0; i < parameterCount; i++) {
 
 			MethodParameter methodParameter = new MethodParameter(method, i);
-			methodParameter.initParameterNameDiscovery(discoverer);
+			methodParameter.initParameterNameDiscovery(PARAMETER_NAME_DISCOVERER);
 
 			T parameter = createParameter(methodParameter);