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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.lang3.reflect;
18  
19  import java.lang.annotation.Annotation;
20  import java.lang.reflect.Array;
21  import java.lang.reflect.InvocationTargetException;
22  import java.lang.reflect.Method;
23  import java.lang.reflect.Modifier;
24  import java.lang.reflect.Type;
25  import java.lang.reflect.TypeVariable;
26  import java.util.ArrayList;
27  import java.util.Arrays;
28  import java.util.Comparator;
29  import java.util.Iterator;
30  import java.util.LinkedHashSet;
31  import java.util.List;
32  import java.util.Map;
33  import java.util.Set;
34  import java.util.TreeMap;
35  import java.util.stream.Collectors;
36  
37  import org.apache.commons.lang3.ArrayUtils;
38  import org.apache.commons.lang3.ClassUtils;
39  import org.apache.commons.lang3.ClassUtils.Interfaces;
40  import org.apache.commons.lang3.Validate;
41  
42  import static java.util.stream.Collectors.toList;
43  
44  /**
45   * <p>Utility reflection methods focused on {@link Method}s, originally from Commons BeanUtils.
46   * Differences from the BeanUtils version may be noted, especially where similar functionality
47   * already existed within Lang.
48   * </p>
49   *
50   * <h2>Known Limitations</h2>
51   * <h3>Accessing Public Methods In A Default Access Superclass</h3>
52   * <p>There is an issue when invoking {@code public} methods contained in a default access superclass on JREs prior to 1.4.
53   * Reflection locates these methods fine and correctly assigns them as {@code public}.
54   * However, an {@link IllegalAccessException} is thrown if the method is invoked.</p>
55   *
56   * <p>{@link MethodUtils} contains a workaround for this situation.
57   * It will attempt to call {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} on this method.
58   * If this call succeeds, then the method can be invoked as normal.
59   * This call will only succeed when the application has sufficient security privileges.
60   * If this call fails then the method may fail.</p>
61   *
62   * @since 2.5
63   */
64  public class MethodUtils {
65  
66      private static final Comparator<Method> METHOD_BY_SIGNATURE = Comparator.comparing(Method::toString);
67  
68      /**
69       * <p>{@link MethodUtils} instances should NOT be constructed in standard programming.
70       * Instead, the class should be used as
71       * {@code MethodUtils.getAccessibleMethod(method)}.</p>
72       *
73       * <p>This constructor is {@code public} to permit tools that require a JavaBean
74       * instance to operate.</p>
75       */
76      public MethodUtils() {
77      }
78  
79      /**
80       * <p>Invokes a named method without parameters.</p>
81       *
82       * <p>This method delegates the method search to {@link #getMatchingAccessibleMethod(Class, String, Class[])}.</p>
83       *
84       * <p>This is a convenient wrapper for
85       * {@link #invokeMethod(Object object, String methodName, Object[] args, Class[] parameterTypes)}.
86       * </p>
87       *
88       * @param object invoke method on this object
89       * @param methodName get method with this name
90       * @return The value returned by the invoked method
91       *
92       * @throws NoSuchMethodException if there is no such accessible method
93       * @throws InvocationTargetException wraps an exception thrown by the method invoked
94       * @throws IllegalAccessException if the requested method is not accessible via reflection
95       *
96       *  @since 3.4
97       */
98      public static Object invokeMethod(final Object object, final String methodName) throws NoSuchMethodException,
99              IllegalAccessException, InvocationTargetException {
100         return invokeMethod(object, methodName, ArrayUtils.EMPTY_OBJECT_ARRAY, null);
101     }
102 
103     /**
104      * <p>Invokes a named method without parameters.</p>
105      *
106      * <p>This is a convenient wrapper for
107      * {@link #invokeMethod(Object object, boolean forceAccess, String methodName, Object[] args, Class[] parameterTypes)}.
108      * </p>
109      *
110      * @param object invoke method on this object
111      * @param forceAccess force access to invoke method even if it's not accessible
112      * @param methodName get method with this name
113      * @return The value returned by the invoked method
114      *
115      * @throws NoSuchMethodException if there is no such accessible method
116      * @throws InvocationTargetException wraps an exception thrown by the method invoked
117      * @throws IllegalAccessException if the requested method is not accessible via reflection
118      *
119      * @since 3.5
120      */
121     public static Object invokeMethod(final Object object, final boolean forceAccess, final String methodName)
122             throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
123         return invokeMethod(object, forceAccess, methodName, ArrayUtils.EMPTY_OBJECT_ARRAY, null);
124     }
125 
126     /**
127      * <p>Invokes a named method whose parameter type matches the object type.</p>
128      *
129      * <p>This method delegates the method search to {@link #getMatchingAccessibleMethod(Class, String, Class[])}.</p>
130      *
131      * <p>This method supports calls to methods taking primitive parameters
132      * via passing in wrapping classes. So, for example, a {@code Boolean} object
133      * would match a {@code boolean} primitive.</p>
134      *
135      * <p>This is a convenient wrapper for
136      * {@link #invokeMethod(Object object, String methodName, Object[] args, Class[] parameterTypes)}.
137      * </p>
138      *
139      * @param object invoke method on this object
140      * @param methodName get method with this name
141      * @param args use these arguments - treat null as empty array
142      * @return The value returned by the invoked method
143      *
144      * @throws NoSuchMethodException if there is no such accessible method
145      * @throws InvocationTargetException wraps an exception thrown by the method invoked
146      * @throws IllegalAccessException if the requested method is not accessible via reflection
147      */
148     public static Object invokeMethod(final Object object, final String methodName,
149             Object... args) throws NoSuchMethodException,
150             IllegalAccessException, InvocationTargetException {
151         args = ArrayUtils.nullToEmpty(args);
152         final Class<?>[] parameterTypes = ClassUtils.toClass(args);
153         return invokeMethod(object, methodName, args, parameterTypes);
154     }
155 
156     /**
157      * <p>Invokes a named method whose parameter type matches the object type.</p>
158      *
159      * <p>This method supports calls to methods taking primitive parameters
160      * via passing in wrapping classes. So, for example, a {@code Boolean} object
161      * would match a {@code boolean} primitive.</p>
162      *
163      * <p>This is a convenient wrapper for
164      * {@link #invokeMethod(Object object, boolean forceAccess, String methodName, Object[] args, Class[] parameterTypes)}.
165      * </p>
166      *
167      * @param object invoke method on this object
168      * @param forceAccess force access to invoke method even if it's not accessible
169      * @param methodName get method with this name
170      * @param args use these arguments - treat null as empty array
171      * @return The value returned by the invoked method
172      *
173      * @throws NoSuchMethodException if there is no such accessible method
174      * @throws InvocationTargetException wraps an exception thrown by the method invoked
175      * @throws IllegalAccessException if the requested method is not accessible via reflection
176      *
177      * @since 3.5
178      */
179     public static Object invokeMethod(final Object object, final boolean forceAccess, final String methodName,
180             Object... args) throws NoSuchMethodException,
181             IllegalAccessException, InvocationTargetException {
182         args = ArrayUtils.nullToEmpty(args);
183         final Class<?>[] parameterTypes = ClassUtils.toClass(args);
184         return invokeMethod(object, forceAccess, methodName, args, parameterTypes);
185     }
186 
187     /**
188      * <p>Invokes a named method whose parameter type matches the object type.</p>
189      *
190      * <p>This method supports calls to methods taking primitive parameters
191      * via passing in wrapping classes. So, for example, a {@code Boolean} object
192      * would match a {@code boolean} primitive.</p>
193      *
194      * @param object invoke method on this object
195      * @param forceAccess force access to invoke method even if it's not accessible
196      * @param methodName get method with this name
197      * @param args use these arguments - treat null as empty array
198      * @param parameterTypes match these parameters - treat null as empty array
199      * @return The value returned by the invoked method
200      *
201      * @throws NoSuchMethodException if there is no such accessible method
202      * @throws InvocationTargetException wraps an exception thrown by the method invoked
203      * @throws IllegalAccessException if the requested method is not accessible via reflection
204      * @since 3.5
205      */
206     public static Object invokeMethod(final Object object, final boolean forceAccess, final String methodName,
207             Object[] args, Class<?>[] parameterTypes)
208             throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
209         parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
210         args = ArrayUtils.nullToEmpty(args);
211 
212         final String messagePrefix;
213         Method method = null;
214 
215         if (forceAccess) {
216             messagePrefix = "No such method: ";
217             method = getMatchingMethod(object.getClass(),
218                     methodName, parameterTypes);
219             if (method != null && !method.isAccessible()) {
220                 method.setAccessible(true);
221             }
222         } else {
223             messagePrefix = "No such accessible method: ";
224             method = getMatchingAccessibleMethod(object.getClass(),
225                     methodName, parameterTypes);
226         }
227 
228         if (method == null) {
229             throw new NoSuchMethodException(messagePrefix
230                     + methodName + "() on object: "
231                     + object.getClass().getName());
232         }
233         args = toVarArgs(method, args);
234 
235         return method.invoke(object, args);
236     }
237 
238     /**
239      * <p>Invokes a named method whose parameter type matches the object type.</p>
240      *
241      * <p>This method delegates the method search to {@link #getMatchingAccessibleMethod(Class, String, Class[])}.</p>
242      *
243      * <p>This method supports calls to methods taking primitive parameters
244      * via passing in wrapping classes. So, for example, a {@code Boolean} object
245      * would match a {@code boolean} primitive.</p>
246      *
247      * @param object invoke method on this object
248      * @param methodName get method with this name
249      * @param args use these arguments - treat null as empty array
250      * @param parameterTypes match these parameters - treat null as empty array
251      * @return The value returned by the invoked method
252      *
253      * @throws NoSuchMethodException if there is no such accessible method
254      * @throws InvocationTargetException wraps an exception thrown by the method invoked
255      * @throws IllegalAccessException if the requested method is not accessible via reflection
256      */
257     public static Object invokeMethod(final Object object, final String methodName,
258             final Object[] args, final Class<?>[] parameterTypes)
259             throws NoSuchMethodException, IllegalAccessException,
260             InvocationTargetException {
261         return invokeMethod(object, false, methodName, args, parameterTypes);
262     }
263 
264     /**
265      * <p>Invokes a method whose parameter types match exactly the object
266      * types.</p>
267      *
268      * <p>This uses reflection to invoke the method obtained from a call to
269      * {@link #getAccessibleMethod}(Class, String, Class[])}.</p>
270      *
271      * @param object invoke method on this object
272      * @param methodName get method with this name
273      * @return The value returned by the invoked method
274      *
275      * @throws NoSuchMethodException if there is no such accessible method
276      * @throws InvocationTargetException wraps an exception thrown by the
277      *  method invoked
278      * @throws IllegalAccessException if the requested method is not accessible
279      *  via reflection
280      *
281      * @since 3.4
282      */
283     public static Object invokeExactMethod(final Object object, final String methodName) throws NoSuchMethodException,
284             IllegalAccessException, InvocationTargetException {
285         return invokeExactMethod(object, methodName, ArrayUtils.EMPTY_OBJECT_ARRAY, null);
286     }
287 
288     /**
289      * <p>Invokes a method with no parameters.</p>
290      *
291      * <p>This uses reflection to invoke the method obtained from a call to
292      * {@link #getAccessibleMethod}(Class, String, Class[])}.</p>
293      *
294      * @param object invoke method on this object
295      * @param methodName get method with this name
296      * @param args use these arguments - treat null as empty array
297      * @return The value returned by the invoked method
298      *
299      * @throws NoSuchMethodException if there is no such accessible method
300      * @throws InvocationTargetException wraps an exception thrown by the
301      *  method invoked
302      * @throws IllegalAccessException if the requested method is not accessible
303      *  via reflection
304      */
305     public static Object invokeExactMethod(final Object object, final String methodName,
306             Object... args) throws NoSuchMethodException,
307             IllegalAccessException, InvocationTargetException {
308         args = ArrayUtils.nullToEmpty(args);
309         final Class<?>[] parameterTypes = ClassUtils.toClass(args);
310         return invokeExactMethod(object, methodName, args, parameterTypes);
311     }
312 
313     /**
314      * <p>Invokes a method whose parameter types match exactly the parameter
315      * types given.</p>
316      *
317      * <p>This uses reflection to invoke the method obtained from a call to
318      * {@link #getAccessibleMethod(Class, String, Class[])}.</p>
319      *
320      * @param object invoke method on this object
321      * @param methodName get method with this name
322      * @param args use these arguments - treat null as empty array
323      * @param parameterTypes match these parameters - treat {@code null} as empty array
324      * @return The value returned by the invoked method
325      *
326      * @throws NoSuchMethodException if there is no such accessible method
327      * @throws InvocationTargetException wraps an exception thrown by the
328      *  method invoked
329      * @throws IllegalAccessException if the requested method is not accessible
330      *  via reflection
331      */
332     public static Object invokeExactMethod(final Object object, final String methodName,
333             Object[] args, Class<?>[] parameterTypes)
334             throws NoSuchMethodException, IllegalAccessException,
335             InvocationTargetException {
336         args = ArrayUtils.nullToEmpty(args);
337         parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
338         final Method method = getAccessibleMethod(object.getClass(), methodName,
339                 parameterTypes);
340         if (method == null) {
341             throw new NoSuchMethodException("No such accessible method: "
342                     + methodName + "() on object: "
343                     + object.getClass().getName());
344         }
345         return method.invoke(object, args);
346     }
347 
348     /**
349      * <p>Invokes a {@code static} method whose parameter types match exactly the parameter
350      * types given.</p>
351      *
352      * <p>This uses reflection to invoke the method obtained from a call to
353      * {@link #getAccessibleMethod(Class, String, Class[])}.</p>
354      *
355      * @param cls invoke static method on this class
356      * @param methodName get method with this name
357      * @param args use these arguments - treat {@code null} as empty array
358      * @param parameterTypes match these parameters - treat {@code null} as empty array
359      * @return The value returned by the invoked method
360      *
361      * @throws NoSuchMethodException if there is no such accessible method
362      * @throws InvocationTargetException wraps an exception thrown by the
363      *  method invoked
364      * @throws IllegalAccessException if the requested method is not accessible
365      *  via reflection
366      */
367     public static Object invokeExactStaticMethod(final Class<?> cls, final String methodName,
368             Object[] args, Class<?>[] parameterTypes)
369             throws NoSuchMethodException, IllegalAccessException,
370             InvocationTargetException {
371         args = ArrayUtils.nullToEmpty(args);
372         parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
373         final Method method = getAccessibleMethod(cls, methodName, parameterTypes);
374         if (method == null) {
375             throw new NoSuchMethodException("No such accessible method: "
376                     + methodName + "() on class: " + cls.getName());
377         }
378         return method.invoke(null, args);
379     }
380 
381     /**
382      * <p>Invokes a named {@code static} method whose parameter type matches the object type.</p>
383      *
384      * <p>This method delegates the method search to {@link #getMatchingAccessibleMethod(Class, String, Class[])}.</p>
385      *
386      * <p>This method supports calls to methods taking primitive parameters
387      * via passing in wrapping classes. So, for example, a {@code Boolean} class
388      * would match a {@code boolean} primitive.</p>
389      *
390      * <p>This is a convenient wrapper for
391      * {@link #invokeStaticMethod(Class, String, Object[], Class[])}.
392      * </p>
393      *
394      * @param cls invoke static method on this class
395      * @param methodName get method with this name
396      * @param args use these arguments - treat {@code null} as empty array
397      * @return The value returned by the invoked method
398      *
399      * @throws NoSuchMethodException if there is no such accessible method
400      * @throws InvocationTargetException wraps an exception thrown by the
401      *  method invoked
402      * @throws IllegalAccessException if the requested method is not accessible
403      *  via reflection
404      */
405     public static Object invokeStaticMethod(final Class<?> cls, final String methodName,
406             Object... args) throws NoSuchMethodException,
407             IllegalAccessException, InvocationTargetException {
408         args = ArrayUtils.nullToEmpty(args);
409         final Class<?>[] parameterTypes = ClassUtils.toClass(args);
410         return invokeStaticMethod(cls, methodName, args, parameterTypes);
411     }
412 
413     /**
414      * <p>Invokes a named {@code static} method whose parameter type matches the object type.</p>
415      *
416      * <p>This method delegates the method search to {@link #getMatchingAccessibleMethod(Class, String, Class[])}.</p>
417      *
418      * <p>This method supports calls to methods taking primitive parameters
419      * via passing in wrapping classes. So, for example, a {@code Boolean} class
420      * would match a {@code boolean} primitive.</p>
421      *
422      *
423      * @param cls invoke static method on this class
424      * @param methodName get method with this name
425      * @param args use these arguments - treat {@code null} as empty array
426      * @param parameterTypes match these parameters - treat {@code null} as empty array
427      * @return The value returned by the invoked method
428      *
429      * @throws NoSuchMethodException if there is no such accessible method
430      * @throws InvocationTargetException wraps an exception thrown by the
431      *  method invoked
432      * @throws IllegalAccessException if the requested method is not accessible
433      *  via reflection
434      */
435     public static Object invokeStaticMethod(final Class<?> cls, final String methodName,
436             Object[] args, Class<?>[] parameterTypes)
437             throws NoSuchMethodException, IllegalAccessException,
438             InvocationTargetException {
439         args = ArrayUtils.nullToEmpty(args);
440         parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
441         final Method method = getMatchingAccessibleMethod(cls, methodName,
442                 parameterTypes);
443         if (method == null) {
444             throw new NoSuchMethodException("No such accessible method: "
445                     + methodName + "() on class: " + cls.getName());
446         }
447         args = toVarArgs(method, args);
448         return method.invoke(null, args);
449     }
450 
451     private static Object[] toVarArgs(final Method method, Object[] args) {
452         if (method.isVarArgs()) {
453             final Class<?>[] methodParameterTypes = method.getParameterTypes();
454             args = getVarArgs(args, methodParameterTypes);
455         }
456         return args;
457     }
458 
459     /**
460      * <p>Given an arguments array passed to a varargs method, return an array of arguments in the canonical form,
461      * i.e. an array with the declared number of parameters, and whose last parameter is an array of the varargs type.
462      * </p>
463      *
464      * @param args the array of arguments passed to the varags method
465      * @param methodParameterTypes the declared array of method parameter types
466      * @return an array of the variadic arguments passed to the method
467      * @since 3.5
468      */
469     static Object[] getVarArgs(final Object[] args, final Class<?>[] methodParameterTypes) {
470         if (args.length == methodParameterTypes.length && (args[args.length - 1] == null ||
471                 args[args.length - 1].getClass().equals(methodParameterTypes[methodParameterTypes.length - 1]))) {
472             // The args array is already in the canonical form for the method.
473             return args;
474         }
475 
476         // Construct a new array matching the method's declared parameter types.
477         final Object[] newArgs = new Object[methodParameterTypes.length];
478 
479         // Copy the normal (non-varargs) parameters
480         System.arraycopy(args, 0, newArgs, 0, methodParameterTypes.length - 1);
481 
482         // Construct a new array for the variadic parameters
483         final Class<?> varArgComponentType = methodParameterTypes[methodParameterTypes.length - 1].getComponentType();
484         final int varArgLength = args.length - methodParameterTypes.length + 1;
485 
486         Object varArgsArray = Array.newInstance(ClassUtils.primitiveToWrapper(varArgComponentType), varArgLength);
487         // Copy the variadic arguments into the varargs array.
488         System.arraycopy(args, methodParameterTypes.length - 1, varArgsArray, 0, varArgLength);
489 
490         if (varArgComponentType.isPrimitive()) {
491             // unbox from wrapper type to primitive type
492             varArgsArray = ArrayUtils.toPrimitive(varArgsArray);
493         }
494 
495         // Store the varargs array in the last position of the array to return
496         newArgs[methodParameterTypes.length - 1] = varArgsArray;
497 
498         // Return the canonical varargs array.
499         return newArgs;
500     }
501 
502     /**
503      * <p>Invokes a {@code static} method whose parameter types match exactly the object
504      * types.</p>
505      *
506      * <p>This uses reflection to invoke the method obtained from a call to
507      * {@link #getAccessibleMethod(Class, String, Class[])}.</p>
508      *
509      * @param cls invoke static method on this class
510      * @param methodName get method with this name
511      * @param args use these arguments - treat {@code null} as empty array
512      * @return The value returned by the invoked method
513      *
514      * @throws NoSuchMethodException if there is no such accessible method
515      * @throws InvocationTargetException wraps an exception thrown by the
516      *  method invoked
517      * @throws IllegalAccessException if the requested method is not accessible
518      *  via reflection
519      */
520     public static Object invokeExactStaticMethod(final Class<?> cls, final String methodName,
521             Object... args) throws NoSuchMethodException,
522             IllegalAccessException, InvocationTargetException {
523         args = ArrayUtils.nullToEmpty(args);
524         final Class<?>[] parameterTypes = ClassUtils.toClass(args);
525         return invokeExactStaticMethod(cls, methodName, args, parameterTypes);
526     }
527 
528     /**
529      * <p>Returns an accessible method (that is, one that can be invoked via
530      * reflection) with given name and parameters. If no such method
531      * can be found, return {@code null}.
532      * This is just a convenience wrapper for
533      * {@link #getAccessibleMethod(Method)}.</p>
534      *
535      * @param cls get method from this class
536      * @param methodName get method with this name
537      * @param parameterTypes with these parameters types
538      * @return The accessible method
539      */
540     public static Method getAccessibleMethod(final Class<?> cls, final String methodName,
541             final Class<?>... parameterTypes) {
542         try {
543             return getAccessibleMethod(cls.getMethod(methodName,
544                     parameterTypes));
545         } catch (final NoSuchMethodException e) {
546             return null;
547         }
548     }
549 
550     /**
551      * <p>Returns an accessible method (that is, one that can be invoked via
552      * reflection) that implements the specified Method. If no such method
553      * can be found, return {@code null}.</p>
554      *
555      * @param method The method that we wish to call
556      * @return The accessible method
557      */
558     public static Method getAccessibleMethod(Method method) {
559         if (!MemberUtils.isAccessible(method)) {
560             return null;
561         }
562         // If the declaring class is public, we are done
563         final Class<?> cls = method.getDeclaringClass();
564         if (Modifier.isPublic(cls.getModifiers())) {
565             return method;
566         }
567         final String methodName = method.getName();
568         final Class<?>[] parameterTypes = method.getParameterTypes();
569 
570         // Check the implemented interfaces and subinterfaces
571         method = getAccessibleMethodFromInterfaceNest(cls, methodName,
572                 parameterTypes);
573 
574         // Check the superclass chain
575         if (method == null) {
576             method = getAccessibleMethodFromSuperclass(cls, methodName,
577                     parameterTypes);
578         }
579         return method;
580     }
581 
582     /**
583      * <p>Returns an accessible method (that is, one that can be invoked via
584      * reflection) by scanning through the superclasses. If no such method
585      * can be found, return {@code null}.</p>
586      *
587      * @param cls Class to be checked
588      * @param methodName Method name of the method we wish to call
589      * @param parameterTypes The parameter type signatures
590      * @return the accessible method or {@code null} if not found
591      */
592     private static Method getAccessibleMethodFromSuperclass(final Class<?> cls,
593             final String methodName, final Class<?>... parameterTypes) {
594         Class<?> parentClass = cls.getSuperclass();
595         while (parentClass != null) {
596             if (Modifier.isPublic(parentClass.getModifiers())) {
597                 try {
598                     return parentClass.getMethod(methodName, parameterTypes);
599                 } catch (final NoSuchMethodException e) {
600                     return null;
601                 }
602             }
603             parentClass = parentClass.getSuperclass();
604         }
605         return null;
606     }
607 
608     /**
609      * <p>Returns an accessible method (that is, one that can be invoked via
610      * reflection) that implements the specified method, by scanning through
611      * all implemented interfaces and subinterfaces. If no such method
612      * can be found, return {@code null}.</p>
613      *
614      * <p>There isn't any good reason why this method must be {@code private}.
615      * It is because there doesn't seem any reason why other classes should
616      * call this rather than the higher level methods.</p>
617      *
618      * @param cls Parent class for the interfaces to be checked
619      * @param methodName Method name of the method we wish to call
620      * @param parameterTypes The parameter type signatures
621      * @return the accessible method or {@code null} if not found
622      */
623     private static Method getAccessibleMethodFromInterfaceNest(Class<?> cls,
624             final String methodName, final Class<?>... parameterTypes) {
625         // Search up the superclass chain
626         for (; cls != null; cls = cls.getSuperclass()) {
627 
628             // Check the implemented interfaces of the parent class
629             final Class<?>[] interfaces = cls.getInterfaces();
630             for (final Class<?> anInterface : interfaces) {
631                 // Is this interface public?
632                 if (!Modifier.isPublic(anInterface.getModifiers())) {
633                     continue;
634                 }
635                 // Does the method exist on this interface?
636                 try {
637                     return anInterface.getDeclaredMethod(methodName,
638                             parameterTypes);
639                 } catch (final NoSuchMethodException e) { // NOPMD
640                     /*
641                      * Swallow, if no method is found after the loop then this
642                      * method returns null.
643                      */
644                 }
645                 // Recursively check our parent interfaces
646                 final Method method = getAccessibleMethodFromInterfaceNest(anInterface,
647                         methodName, parameterTypes);
648                 if (method != null) {
649                     return method;
650                 }
651             }
652         }
653         return null;
654     }
655 
656     /**
657      * <p>Finds an accessible method that matches the given name and has compatible parameters.
658      * Compatible parameters mean that every method parameter is assignable from
659      * the given parameters.
660      * In other words, it finds a method with the given name
661      * that will take the parameters given.</p>
662      *
663      * <p>This method is used by
664      * {@link
665      * #invokeMethod(Object object, String methodName, Object[] args, Class[] parameterTypes)}.
666      * </p>
667      *
668      * <p>This method can match primitive parameter by passing in wrapper classes.
669      * For example, a {@code Boolean} will match a primitive {@code boolean}
670      * parameter.
671      * </p>
672      *
673      * @param cls find method in this class
674      * @param methodName find method with this name
675      * @param parameterTypes find method with most compatible parameters
676      * @return The accessible method
677      */
678     public static Method getMatchingAccessibleMethod(final Class<?> cls,
679             final String methodName, final Class<?>... parameterTypes) {
680         try {
681             final Method method = cls.getMethod(methodName, parameterTypes);
682             MemberUtils.setAccessibleWorkaround(method);
683             return method;
684         } catch (final NoSuchMethodException e) { // NOPMD - Swallow the exception
685         }
686         // search through all methods
687         final Method[] methods = cls.getMethods();
688         final List<Method> matchingMethods = new ArrayList<>();
689         for (final Method method : methods) {
690             // compare name and parameters
691             if (method.getName().equals(methodName) &&
692                     MemberUtils.isMatchingMethod(method, parameterTypes)) {
693                 matchingMethods.add (method);
694             }
695         }
696 
697         // Sort methods by signature to force deterministic result
698         matchingMethods.sort(METHOD_BY_SIGNATURE);
699 
700         Method bestMatch = null;
701         for (final Method method : matchingMethods) {
702             // get accessible version of method
703             final Method accessibleMethod = getAccessibleMethod(method);
704             if (accessibleMethod != null && (bestMatch == null || MemberUtils.compareMethodFit(
705                         accessibleMethod,
706                         bestMatch,
707                         parameterTypes) < 0)) {
708                 bestMatch = accessibleMethod;
709             }
710         }
711         if (bestMatch != null) {
712             MemberUtils.setAccessibleWorkaround(bestMatch);
713         }
714 
715         if (bestMatch != null && bestMatch.isVarArgs() && bestMatch.getParameterTypes().length > 0 && parameterTypes.length > 0) {
716             final Class<?>[] methodParameterTypes = bestMatch.getParameterTypes();
717             final Class<?> methodParameterComponentType = methodParameterTypes[methodParameterTypes.length - 1].getComponentType();
718             final String methodParameterComponentTypeName = ClassUtils.primitiveToWrapper(methodParameterComponentType).getName();
719 
720             final Class<?> lastParameterType = parameterTypes[parameterTypes.length - 1];
721             final String parameterTypeName = (lastParameterType==null) ? null : lastParameterType.getName();
722             final String parameterTypeSuperClassName = (lastParameterType==null) ? null : lastParameterType.getSuperclass().getName();
723 
724             if (parameterTypeName!= null && parameterTypeSuperClassName != null && !methodParameterComponentTypeName.equals(parameterTypeName)
725                     && !methodParameterComponentTypeName.equals(parameterTypeSuperClassName)) {
726                 return null;
727             }
728         }
729 
730         return bestMatch;
731     }
732 
733     /**
734      * <p>Retrieves a method whether or not it's accessible. If no such method
735      * can be found, return {@code null}.</p>
736      * @param cls The class that will be subjected to the method search
737      * @param methodName The method that we wish to call
738      * @param parameterTypes Argument class types
739      * @return The method
740      *
741      * @since 3.5
742      */
743     public static Method getMatchingMethod(final Class<?> cls, final String methodName,
744             final Class<?>... parameterTypes) {
745         Validate.notNull(cls, "cls");
746         Validate.notEmpty(methodName, "methodName");
747 
748         final List<Method> methods = Arrays.stream(cls.getDeclaredMethods())
749                 .filter(method -> method.getName().equals(methodName))
750                 .collect(toList());
751 
752         ClassUtils.getAllSuperclasses(cls).stream()
753                 .map(Class::getDeclaredMethods)
754                 .flatMap(Arrays::stream)
755                 .filter(method -> method.getName().equals(methodName))
756                 .forEach(methods::add);
757 
758         for (final Method method : methods) {
759             if (Arrays.deepEquals(method.getParameterTypes(), parameterTypes)) {
760                 return method;
761             }
762         }
763 
764         final TreeMap<Integer, List<Method>> candidates = new TreeMap<>();
765 
766         methods.stream()
767                 .filter(method -> ClassUtils.isAssignable(parameterTypes, method.getParameterTypes(), true))
768                 .forEach(method -> {
769                     final int distance = distance(parameterTypes, method.getParameterTypes());
770                     final List<Method> candidatesAtDistance = candidates.computeIfAbsent(distance, k -> new ArrayList<>());
771                     candidatesAtDistance.add(method);
772                 });
773 
774         if (candidates.isEmpty()) {
775             return null;
776         }
777 
778         final List<Method> bestCandidates = candidates.values().iterator().next();
779         if (bestCandidates.size() == 1) {
780             return bestCandidates.get(0);
781         }
782 
783         throw new IllegalStateException(
784                 String.format("Found multiple candidates for method %s on class %s : %s",
785                         methodName + Arrays.stream(parameterTypes).map(String::valueOf).collect(Collectors.joining(",", "(", ")")),
786                         cls.getName(),
787                         bestCandidates.stream().map(Method::toString).collect(Collectors.joining(",", "[", "]")))
788         );
789     }
790 
791     /**
792      * <p>Returns the aggregate number of inheritance hops between assignable argument class types.  Returns -1
793      * if the arguments aren't assignable.  Fills a specific purpose for getMatchingMethod and is not generalized.</p>
794      * @param fromClassArray the Class array to calculate the distance from.
795      * @param toClassArray the Class array to calculate the distance to.
796      * @return the aggregate number of inheritance hops between assignable argument class types.
797      */
798     private static int distance(final Class<?>[] fromClassArray, final Class<?>[] toClassArray) {
799         int answer = 0;
800 
801         if (!ClassUtils.isAssignable(fromClassArray, toClassArray, true)) {
802             return -1;
803         }
804         for (int offset = 0; offset < fromClassArray.length; offset++) {
805             // Note InheritanceUtils.distance() uses different scoring system.
806             final Class<?> aClass = fromClassArray[offset];
807             final Class<?> toClass = toClassArray[offset];
808             if (aClass == null || aClass.equals(toClass)) {
809                 continue;
810             } else if (ClassUtils.isAssignable(aClass, toClass, true)
811                     && !ClassUtils.isAssignable(aClass, toClass, false)) {
812                 answer++;
813             } else {
814                 answer = answer + 2;
815             }
816         }
817 
818         return answer;
819     }
820 
821     /**
822      * Gets the hierarchy of overridden methods down to {@code result} respecting generics.
823      * @param method lowest to consider
824      * @param interfacesBehavior whether to search interfaces, {@code null} {@code implies} false
825      * @return Set&lt;Method&gt; in ascending order from sub- to superclass
826      * @throws NullPointerException if the specified method is {@code null}
827      * @since 3.2
828      */
829     public static Set<Method> getOverrideHierarchy(final Method method, final Interfaces interfacesBehavior) {
830         Validate.notNull(method);
831         final Set<Method> result = new LinkedHashSet<>();
832         result.add(method);
833 
834         final Class<?>[] parameterTypes = method.getParameterTypes();
835 
836         final Class<?> declaringClass = method.getDeclaringClass();
837 
838         final Iterator<Class<?>> hierarchy = ClassUtils.hierarchy(declaringClass, interfacesBehavior).iterator();
839         //skip the declaring class :P
840         hierarchy.next();
841         hierarchyTraversal: while (hierarchy.hasNext()) {
842             final Class<?> c = hierarchy.next();
843             final Method m = getMatchingAccessibleMethod(c, method.getName(), parameterTypes);
844             if (m == null) {
845                 continue;
846             }
847             if (Arrays.equals(m.getParameterTypes(), parameterTypes)) {
848                 // matches without generics
849                 result.add(m);
850                 continue;
851             }
852             // necessary to get arguments every time in the case that we are including interfaces
853             final Map<TypeVariable<?>, Type> typeArguments = TypeUtils.getTypeArguments(declaringClass, m.getDeclaringClass());
854             for (int i = 0; i < parameterTypes.length; i++) {
855                 final Type childType = TypeUtils.unrollVariables(typeArguments, method.getGenericParameterTypes()[i]);
856                 final Type parentType = TypeUtils.unrollVariables(typeArguments, m.getGenericParameterTypes()[i]);
857                 if (!TypeUtils.equals(childType, parentType)) {
858                     continue hierarchyTraversal;
859                 }
860             }
861             result.add(m);
862         }
863         return result;
864     }
865 
866     /**
867      * Gets all class level public methods of the given class that are annotated with the given annotation.
868      * @param cls
869      *            the {@link Class} to query
870      * @param annotationCls
871      *            the {@link java.lang.annotation.Annotation} that must be present on a method to be matched
872      * @return an array of Methods (possibly empty).
873      * @throws NullPointerException if the class or annotation are {@code null}
874      * @since 3.4
875      */
876     public static Method[] getMethodsWithAnnotation(final Class<?> cls, final Class<? extends Annotation> annotationCls) {
877         return getMethodsWithAnnotation(cls, annotationCls, false, false);
878     }
879 
880     /**
881      * Gets all class level public methods of the given class that are annotated with the given annotation.
882      * @param cls
883      *            the {@link Class} to query
884      * @param annotationCls
885      *            the {@link Annotation} that must be present on a method to be matched
886      * @return a list of Methods (possibly empty).
887      * @throws IllegalArgumentException
888      *            if the class or annotation are {@code null}
889      * @since 3.4
890      */
891     public static List<Method> getMethodsListWithAnnotation(final Class<?> cls, final Class<? extends Annotation> annotationCls) {
892         return getMethodsListWithAnnotation(cls, annotationCls, false, false);
893     }
894 
895     /**
896      * Gets all methods of the given class that are annotated with the given annotation.
897      * @param cls
898      *            the {@link Class} to query
899      * @param annotationCls
900      *            the {@link java.lang.annotation.Annotation} that must be present on a method to be matched
901      * @param searchSupers
902      *            determines if a lookup in the entire inheritance hierarchy of the given class should be performed
903      * @param ignoreAccess
904      *            determines if non public methods should be considered
905      * @return an array of Methods (possibly empty).
906      * @throws NullPointerException if the class or annotation are {@code null}
907      * @since 3.6
908      */
909     public static Method[] getMethodsWithAnnotation(final Class<?> cls, final Class<? extends Annotation> annotationCls,
910                                                     final boolean searchSupers, final boolean ignoreAccess) {
911         final List<Method> annotatedMethodsList = getMethodsListWithAnnotation(cls, annotationCls, searchSupers,
912                 ignoreAccess);
913         return annotatedMethodsList.toArray(ArrayUtils.EMPTY_METHOD_ARRAY);
914     }
915 
916     /**
917      * Gets all methods of the given class that are annotated with the given annotation.
918      * @param cls
919      *            the {@link Class} to query
920      * @param annotationCls
921      *            the {@link Annotation} that must be present on a method to be matched
922      * @param searchSupers
923      *            determines if a lookup in the entire inheritance hierarchy of the given class should be performed
924      * @param ignoreAccess
925      *            determines if non public methods should be considered
926      * @return a list of Methods (possibly empty).
927      * @throws NullPointerException if either the class or annotation class is {@code null}
928      * @since 3.6
929      */
930     public static List<Method> getMethodsListWithAnnotation(final Class<?> cls,
931                                                             final Class<? extends Annotation> annotationCls,
932                                                             final boolean searchSupers, final boolean ignoreAccess) {
933 
934         Validate.notNull(cls, "cls");
935         Validate.notNull(annotationCls, "annotationCls");
936         final List<Class<?>> classes = (searchSupers ? getAllSuperclassesAndInterfaces(cls)
937                 : new ArrayList<>());
938         classes.add(0, cls);
939         final List<Method> annotatedMethods = new ArrayList<>();
940         for (final Class<?> acls : classes) {
941             final Method[] methods = (ignoreAccess ? acls.getDeclaredMethods() : acls.getMethods());
942             for (final Method method : methods) {
943                 if (method.getAnnotation(annotationCls) != null) {
944                     annotatedMethods.add(method);
945                 }
946             }
947         }
948         return annotatedMethods;
949     }
950 
951     /**
952      * <p>Gets the annotation object with the given annotation type that is present on the given method
953      * or optionally on any equivalent method in super classes and interfaces. Returns null if the annotation
954      * type was not present.</p>
955      *
956      * <p>Stops searching for an annotation once the first annotation of the specified type has been
957      * found. Additional annotations of the specified type will be silently ignored.</p>
958      * @param <A>
959      *            the annotation type
960      * @param method
961      *            the {@link Method} to query
962      * @param annotationCls
963      *            the {@link Annotation} to check if is present on the method
964      * @param searchSupers
965      *            determines if a lookup in the entire inheritance hierarchy of the given class is performed
966      *            if the annotation was not directly present
967      * @param ignoreAccess
968      *            determines if underlying method has to be accessible
969      * @return the first matching annotation, or {@code null} if not found
970      * @throws NullPointerException if either the method or annotation class is {@code null}
971      * @since 3.6
972      */
973     public static <A extends Annotation> A getAnnotation(final Method method, final Class<A> annotationCls,
974                                                          final boolean searchSupers, final boolean ignoreAccess) {
975 
976         Validate.notNull(method, "method");
977         Validate.notNull(annotationCls, "annotationCls");
978         if (!ignoreAccess && !MemberUtils.isAccessible(method)) {
979             return null;
980         }
981 
982         A annotation = method.getAnnotation(annotationCls);
983 
984         if (annotation == null && searchSupers) {
985             final Class<?> mcls = method.getDeclaringClass();
986             final List<Class<?>> classes = getAllSuperclassesAndInterfaces(mcls);
987             for (final Class<?> acls : classes) {
988                 final Method equivalentMethod = (ignoreAccess ? MethodUtils.getMatchingMethod(acls, method.getName(), method.getParameterTypes())
989                     : MethodUtils.getMatchingAccessibleMethod(acls, method.getName(), method.getParameterTypes()));
990                 if (equivalentMethod != null) {
991                     annotation = equivalentMethod.getAnnotation(annotationCls);
992                     if (annotation != null) {
993                         break;
994                     }
995                 }
996             }
997         }
998 
999         return annotation;
1000     }
1001 
1002     /**
1003      * <p>Gets a combination of {@link ClassUtils#getAllSuperclasses(Class)} and
1004      * {@link ClassUtils#getAllInterfaces(Class)}, one from superclasses, one
1005      * from interfaces, and so on in a breadth first way.</p>
1006      *
1007      * @param cls  the class to look up, may be {@code null}
1008      * @return the combined {@code List} of superclasses and interfaces in order
1009      * going up from this one
1010      *  {@code null} if null input
1011      */
1012     private static List<Class<?>> getAllSuperclassesAndInterfaces(final Class<?> cls) {
1013         if (cls == null) {
1014             return null;
1015         }
1016 
1017         final List<Class<?>> allSuperClassesAndInterfaces = new ArrayList<>();
1018         final List<Class<?>> allSuperclasses = ClassUtils.getAllSuperclasses(cls);
1019         int superClassIndex = 0;
1020         final List<Class<?>> allInterfaces = ClassUtils.getAllInterfaces(cls);
1021         int interfaceIndex = 0;
1022         while (interfaceIndex < allInterfaces.size() ||
1023                 superClassIndex < allSuperclasses.size()) {
1024             final Class<?> acls;
1025             if (interfaceIndex >= allInterfaces.size()) {
1026                 acls = allSuperclasses.get(superClassIndex++);
1027             } else if ((superClassIndex >= allSuperclasses.size()) || (interfaceIndex < superClassIndex) || !(superClassIndex < interfaceIndex)) {
1028                 acls = allInterfaces.get(interfaceIndex++);
1029             } else {
1030                 acls = allSuperclasses.get(superClassIndex++);
1031             }
1032             allSuperClassesAndInterfaces.add(acls);
1033         }
1034         return allSuperClassesAndInterfaces;
1035     }
1036 }