DATACMNS-733 - Made all references to DefaultParameterNameDiscoverer non-static.

To prevent classes from being garbage collected due to Class<?> references within DefaultParameterNameDiscoverer we no keep all ParameterNameDiscoverer instances in a non-static field.

src/main/java/org/springframework/data/mapping/model/PreferredConstructorDiscoverer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2014 by the original author(s).
+ * Copyright 2011-2015 by the original author(s).
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -35,7 +35,7 @@ import org.springframework.data.util.TypeInformation;
  */
 public class PreferredConstructorDiscoverer<T, P extends PersistentProperty<P>> {
 
-	private static final ParameterNameDiscoverer PARAMETER_DISCOVERER = new DefaultParameterNameDiscoverer();
+	private final ParameterNameDiscoverer discoverer = new DefaultParameterNameDiscoverer();
 
 	private PreferredConstructor<T, P> constructor;
 
@@ -106,7 +106,7 @@ public class PreferredConstructorDiscoverer<T, P extends PersistentProperty<P>>
 			return new PreferredConstructor<T, P>((Constructor<T>) constructor);
 		}
 
-		String[] parameterNames = PARAMETER_DISCOVERER.getParameterNames(constructor);
+		String[] parameterNames = discoverer.getParameterNames(constructor);
 
 		Parameter<Object, P>[] parameters = new Parameter[parameterTypes.size()];
 		Annotation[][] parameterAnnotations = constructor.getParameterAnnotations();

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

@@ -46,7 +46,7 @@ public abstract class Parameters<S extends Parameters<S, T>, T extends Parameter
 			+ "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 PARAMETER_DISCOVERER = new DefaultParameterNameDiscoverer();
+	private final ParameterNameDiscoverer discoverer = new DefaultParameterNameDiscoverer();
 	private final int pageableIndex;
 	private final int sortIndex;
 	private final List<T> parameters;
@@ -54,7 +54,7 @@ public abstract class Parameters<S extends Parameters<S, T>, T extends Parameter
 	/**
 	 * Creates a new instance of {@link Parameters}.
 	 * 
-	 * @param method
+	 * @param method must not be {@literal null}.
 	 */
 	public Parameters(Method method) {
 
@@ -67,7 +67,7 @@ public abstract class Parameters<S extends Parameters<S, T>, T extends Parameter
 		for (int i = 0; i < types.size(); i++) {
 
 			MethodParameter methodParameter = new MethodParameter(method, i);
-			methodParameter.initParameterNameDiscovery(PARAMETER_DISCOVERER);
+			methodParameter.initParameterNameDiscovery(discoverer);
 
 			T parameter = createParameter(methodParameter);
 

src/main/java/org/springframework/data/repository/support/MethodParameters.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2014 the original author or authors.
+ * Copyright 2012-2015 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -33,8 +33,7 @@ import org.springframework.util.Assert;
  */
 class MethodParameters {
 
-	private static final ParameterNameDiscoverer DISCOVERER = new DefaultParameterNameDiscoverer();
-
+	private final ParameterNameDiscoverer discoverer = new DefaultParameterNameDiscoverer();
 	private final List<MethodParameter> parameters;
 
 	/**
@@ -61,7 +60,7 @@ class MethodParameters {
 		for (int i = 0; i < method.getParameterTypes().length; i++) {
 
 			MethodParameter parameter = new AnnotationNamingMethodParameter(method, i, namingAnnotation);
-			parameter.initParameterNameDiscovery(DISCOVERER);
+			parameter.initParameterNameDiscovery(discoverer);
 			parameters.add(parameter);
 		}
 	}