001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.lang3.reflect;
018
019import java.lang.annotation.Annotation;
020import java.lang.reflect.Array;
021import java.lang.reflect.InvocationTargetException;
022import java.lang.reflect.Method;
023import java.lang.reflect.Modifier;
024import java.lang.reflect.Type;
025import java.lang.reflect.TypeVariable;
026import java.util.ArrayList;
027import java.util.Arrays;
028import java.util.Iterator;
029import java.util.LinkedHashSet;
030import java.util.List;
031import java.util.Map;
032import java.util.Objects;
033import java.util.Set;
034
035import org.apache.commons.lang3.ArrayUtils;
036import org.apache.commons.lang3.ClassUtils;
037import org.apache.commons.lang3.ClassUtils.Interfaces;
038import org.apache.commons.lang3.Validate;
039
040/**
041 * <p>Utility reflection methods focused on {@link Method}s, originally from Commons BeanUtils.
042 * Differences from the BeanUtils version may be noted, especially where similar functionality
043 * already existed within Lang.
044 * </p>
045 *
046 * <h3>Known Limitations</h3>
047 * <h4>Accessing Public Methods In A Default Access Superclass</h4>
048 * <p>There is an issue when invoking {@code public} methods contained in a default access superclass on JREs prior to 1.4.
049 * Reflection locates these methods fine and correctly assigns them as {@code public}.
050 * However, an {@link IllegalAccessException} is thrown if the method is invoked.</p>
051 *
052 * <p>{@link MethodUtils} contains a workaround for this situation.
053 * It will attempt to call {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} on this method.
054 * If this call succeeds, then the method can be invoked as normal.
055 * This call will only succeed when the application has sufficient security privileges.
056 * If this call fails then the method may fail.</p>
057 *
058 * @since 2.5
059 */
060public class MethodUtils {
061
062    /**
063     * <p>{@link MethodUtils} instances should NOT be constructed in standard programming.
064     * Instead, the class should be used as
065     * {@code MethodUtils.getAccessibleMethod(method)}.</p>
066     *
067     * <p>This constructor is {@code public} to permit tools that require a JavaBean
068     * instance to operate.</p>
069     */
070    public MethodUtils() {
071        super();
072    }
073
074    /**
075     * <p>Invokes a named method without parameters.</p>
076     *
077     * <p>This method delegates the method search to {@link #getMatchingAccessibleMethod(Class, String, Class[])}.</p>
078     *
079     * <p>This is a convenient wrapper for
080     * {@link #invokeMethod(Object object,String methodName, Object[] args, Class[] parameterTypes)}.
081     * </p>
082     *
083     * @param object invoke method on this object
084     * @param methodName get method with this name
085     * @return The value returned by the invoked method
086     *
087     * @throws NoSuchMethodException if there is no such accessible method
088     * @throws InvocationTargetException wraps an exception thrown by the method invoked
089     * @throws IllegalAccessException if the requested method is not accessible via reflection
090     *
091     *  @since 3.4
092     */
093    public static Object invokeMethod(final Object object, final String methodName) throws NoSuchMethodException,
094            IllegalAccessException, InvocationTargetException {
095        return invokeMethod(object, methodName, ArrayUtils.EMPTY_OBJECT_ARRAY, null);
096    }
097
098    /**
099     * <p>Invokes a named method without parameters.</p>
100     *
101     * <p>This is a convenient wrapper for
102     * {@link #invokeMethod(Object object,boolean forceAccess,String methodName, Object[] args, Class[] parameterTypes)}.
103     * </p>
104     *
105     * @param object invoke method on this object
106     * @param forceAccess force access to invoke method even if it's not accessible
107     * @param methodName get method with this name
108     * @return The value returned by the invoked method
109     *
110     * @throws NoSuchMethodException if there is no such accessible method
111     * @throws InvocationTargetException wraps an exception thrown by the method invoked
112     * @throws IllegalAccessException if the requested method is not accessible via reflection
113     *
114     * @since 3.5
115     */
116    public static Object invokeMethod(final Object object, final boolean forceAccess, final String methodName)
117            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
118        return invokeMethod(object, forceAccess, methodName, ArrayUtils.EMPTY_OBJECT_ARRAY, null);
119    }
120
121    /**
122     * <p>Invokes a named method whose parameter type matches the object type.</p>
123     *
124     * <p>This method delegates the method search to {@link #getMatchingAccessibleMethod(Class, String, Class[])}.</p>
125     *
126     * <p>This method supports calls to methods taking primitive parameters
127     * via passing in wrapping classes. So, for example, a {@code Boolean} object
128     * would match a {@code boolean} primitive.</p>
129     *
130     * <p>This is a convenient wrapper for
131     * {@link #invokeMethod(Object object,String methodName, Object[] args, Class[] parameterTypes)}.
132     * </p>
133     *
134     * @param object invoke method on this object
135     * @param methodName get method with this name
136     * @param args use these arguments - treat null as empty array
137     * @return The value returned by the invoked method
138     *
139     * @throws NoSuchMethodException if there is no such accessible method
140     * @throws InvocationTargetException wraps an exception thrown by the method invoked
141     * @throws IllegalAccessException if the requested method is not accessible via reflection
142     */
143    public static Object invokeMethod(final Object object, final String methodName,
144            Object... args) throws NoSuchMethodException,
145            IllegalAccessException, InvocationTargetException {
146        args = ArrayUtils.nullToEmpty(args);
147        final Class<?>[] parameterTypes = ClassUtils.toClass(args);
148        return invokeMethod(object, methodName, args, parameterTypes);
149    }
150
151    /**
152     * <p>Invokes a named method whose parameter type matches the object type.</p>
153     *
154     * <p>This method supports calls to methods taking primitive parameters
155     * via passing in wrapping classes. So, for example, a {@code Boolean} object
156     * would match a {@code boolean} primitive.</p>
157     *
158     * <p>This is a convenient wrapper for
159     * {@link #invokeMethod(Object object,boolean forceAccess,String methodName, Object[] args, Class[] parameterTypes)}.
160     * </p>
161     *
162     * @param object invoke method on this object
163     * @param forceAccess force access to invoke method even if it's not accessible
164     * @param methodName get method with this name
165     * @param args use these arguments - treat null as empty array
166     * @return The value returned by the invoked method
167     *
168     * @throws NoSuchMethodException if there is no such accessible method
169     * @throws InvocationTargetException wraps an exception thrown by the method invoked
170     * @throws IllegalAccessException if the requested method is not accessible via reflection
171     *
172     * @since 3.5
173     */
174    public static Object invokeMethod(final Object object, final boolean forceAccess, final String methodName,
175            Object... args) throws NoSuchMethodException,
176            IllegalAccessException, InvocationTargetException {
177        args = ArrayUtils.nullToEmpty(args);
178        final Class<?>[] parameterTypes = ClassUtils.toClass(args);
179        return invokeMethod(object, forceAccess, methodName, args, parameterTypes);
180    }
181
182    /**
183     * <p>Invokes a named method whose parameter type matches the object type.</p>
184     *
185     * <p>This method supports calls to methods taking primitive parameters
186     * via passing in wrapping classes. So, for example, a {@code Boolean} object
187     * would match a {@code boolean} primitive.</p>
188     *
189     * @param object invoke method on this object
190     * @param forceAccess force access to invoke method even if it's not accessible
191     * @param methodName get method with this name
192     * @param args use these arguments - treat null as empty array
193     * @param parameterTypes match these parameters - treat null as empty array
194     * @return The value returned by the invoked method
195     *
196     * @throws NoSuchMethodException if there is no such accessible method
197     * @throws InvocationTargetException wraps an exception thrown by the method invoked
198     * @throws IllegalAccessException if the requested method is not accessible via reflection
199     * @since 3.5
200     */
201    public static Object invokeMethod(final Object object, final boolean forceAccess, final String methodName,
202            Object[] args, Class<?>[] parameterTypes)
203            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
204        parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
205        args = ArrayUtils.nullToEmpty(args);
206
207        final String messagePrefix;
208        Method method = null;
209
210        if (forceAccess) {
211            messagePrefix = "No such method: ";
212            method = getMatchingMethod(object.getClass(),
213                    methodName, parameterTypes);
214            if (method != null && !method.isAccessible()) {
215                method.setAccessible(true);
216            }
217        } else {
218            messagePrefix = "No such accessible method: ";
219            method = getMatchingAccessibleMethod(object.getClass(),
220                    methodName, parameterTypes);
221        }
222
223        if (method == null) {
224            throw new NoSuchMethodException(messagePrefix
225                    + methodName + "() on object: "
226                    + object.getClass().getName());
227        }
228        args = toVarArgs(method, args);
229
230        return method.invoke(object, args);
231    }
232
233    /**
234     * <p>Invokes a named method whose parameter type matches the object type.</p>
235     *
236     * <p>This method delegates the method search to {@link #getMatchingAccessibleMethod(Class, String, Class[])}.</p>
237     *
238     * <p>This method supports calls to methods taking primitive parameters
239     * via passing in wrapping classes. So, for example, a {@code Boolean} object
240     * would match a {@code boolean} primitive.</p>
241     *
242     * @param object invoke method on this object
243     * @param methodName get method with this name
244     * @param args use these arguments - treat null as empty array
245     * @param parameterTypes match these parameters - treat null as empty array
246     * @return The value returned by the invoked method
247     *
248     * @throws NoSuchMethodException if there is no such accessible method
249     * @throws InvocationTargetException wraps an exception thrown by the method invoked
250     * @throws IllegalAccessException if the requested method is not accessible via reflection
251     */
252    public static Object invokeMethod(final Object object, final String methodName,
253            final Object[] args, final Class<?>[] parameterTypes)
254            throws NoSuchMethodException, IllegalAccessException,
255            InvocationTargetException {
256        return invokeMethod(object, false, methodName, args, parameterTypes);
257    }
258
259    /**
260     * <p>Invokes a method whose parameter types match exactly the object
261     * types.</p>
262     *
263     * <p>This uses reflection to invoke the method obtained from a call to
264     * {@link #getAccessibleMethod}(Class,String,Class[])}.</p>
265     *
266     * @param object invoke method on this object
267     * @param methodName get method with this name
268     * @return The value returned by the invoked method
269     *
270     * @throws NoSuchMethodException if there is no such accessible method
271     * @throws InvocationTargetException wraps an exception thrown by the
272     *  method invoked
273     * @throws IllegalAccessException if the requested method is not accessible
274     *  via reflection
275     *
276     * @since 3.4
277     */
278    public static Object invokeExactMethod(final Object object, final String methodName) throws NoSuchMethodException,
279            IllegalAccessException, InvocationTargetException {
280        return invokeExactMethod(object, methodName, ArrayUtils.EMPTY_OBJECT_ARRAY, null);
281    }
282
283    /**
284     * <p>Invokes a method with no parameters.</p>
285     *
286     * <p>This uses reflection to invoke the method obtained from a call to
287     * {@link #getAccessibleMethod}(Class,String,Class[])}.</p>
288     *
289     * @param object invoke method on this object
290     * @param methodName get method with this name
291     * @param args use these arguments - treat null as empty array
292     * @return The value returned by the invoked method
293     *
294     * @throws NoSuchMethodException if there is no such accessible method
295     * @throws InvocationTargetException wraps an exception thrown by the
296     *  method invoked
297     * @throws IllegalAccessException if the requested method is not accessible
298     *  via reflection
299     */
300    public static Object invokeExactMethod(final Object object, final String methodName,
301            Object... args) throws NoSuchMethodException,
302            IllegalAccessException, InvocationTargetException {
303        args = ArrayUtils.nullToEmpty(args);
304        final Class<?>[] parameterTypes = ClassUtils.toClass(args);
305        return invokeExactMethod(object, methodName, args, parameterTypes);
306    }
307
308    /**
309     * <p>Invokes a method whose parameter types match exactly the parameter
310     * types given.</p>
311     *
312     * <p>This uses reflection to invoke the method obtained from a call to
313     * {@link #getAccessibleMethod(Class,String,Class[])}.</p>
314     *
315     * @param object invoke method on this object
316     * @param methodName get method with this name
317     * @param args use these arguments - treat null as empty array
318     * @param parameterTypes match these parameters - treat {@code null} as empty array
319     * @return The value returned by the invoked method
320     *
321     * @throws NoSuchMethodException if there is no such accessible method
322     * @throws InvocationTargetException wraps an exception thrown by the
323     *  method invoked
324     * @throws IllegalAccessException if the requested method is not accessible
325     *  via reflection
326     */
327    public static Object invokeExactMethod(final Object object, final String methodName,
328            Object[] args, Class<?>[] parameterTypes)
329            throws NoSuchMethodException, IllegalAccessException,
330            InvocationTargetException {
331        args = ArrayUtils.nullToEmpty(args);
332        parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
333        final Method method = getAccessibleMethod(object.getClass(), methodName,
334                parameterTypes);
335        if (method == null) {
336            throw new NoSuchMethodException("No such accessible method: "
337                    + methodName + "() on object: "
338                    + object.getClass().getName());
339        }
340        return method.invoke(object, args);
341    }
342
343    /**
344     * <p>Invokes a {@code static} method whose parameter types match exactly the parameter
345     * types given.</p>
346     *
347     * <p>This uses reflection to invoke the method obtained from a call to
348     * {@link #getAccessibleMethod(Class, String, Class[])}.</p>
349     *
350     * @param cls invoke static method on this class
351     * @param methodName get method with this name
352     * @param args use these arguments - treat {@code null} as empty array
353     * @param parameterTypes match these parameters - treat {@code null} as empty array
354     * @return The value returned by the invoked method
355     *
356     * @throws NoSuchMethodException if there is no such accessible method
357     * @throws InvocationTargetException wraps an exception thrown by the
358     *  method invoked
359     * @throws IllegalAccessException if the requested method is not accessible
360     *  via reflection
361     */
362    public static Object invokeExactStaticMethod(final Class<?> cls, final String methodName,
363            Object[] args, Class<?>[] parameterTypes)
364            throws NoSuchMethodException, IllegalAccessException,
365            InvocationTargetException {
366        args = ArrayUtils.nullToEmpty(args);
367        parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
368        final Method method = getAccessibleMethod(cls, methodName, parameterTypes);
369        if (method == null) {
370            throw new NoSuchMethodException("No such accessible method: "
371                    + methodName + "() on class: " + cls.getName());
372        }
373        return method.invoke(null, args);
374    }
375
376    /**
377     * <p>Invokes a named {@code static} method whose parameter type matches the object type.</p>
378     *
379     * <p>This method delegates the method search to {@link #getMatchingAccessibleMethod(Class, String, Class[])}.</p>
380     *
381     * <p>This method supports calls to methods taking primitive parameters
382     * via passing in wrapping classes. So, for example, a {@code Boolean} class
383     * would match a {@code boolean} primitive.</p>
384     *
385     * <p>This is a convenient wrapper for
386     * {@link #invokeStaticMethod(Class, String, Object[], Class[])}.
387     * </p>
388     *
389     * @param cls invoke static method on this class
390     * @param methodName get method with this name
391     * @param args use these arguments - treat {@code null} as empty array
392     * @return The value returned by the invoked method
393     *
394     * @throws NoSuchMethodException if there is no such accessible method
395     * @throws InvocationTargetException wraps an exception thrown by the
396     *  method invoked
397     * @throws IllegalAccessException if the requested method is not accessible
398     *  via reflection
399     */
400    public static Object invokeStaticMethod(final Class<?> cls, final String methodName,
401            Object... args) throws NoSuchMethodException,
402            IllegalAccessException, InvocationTargetException {
403        args = ArrayUtils.nullToEmpty(args);
404        final Class<?>[] parameterTypes = ClassUtils.toClass(args);
405        return invokeStaticMethod(cls, methodName, args, parameterTypes);
406    }
407
408    /**
409     * <p>Invokes a named {@code static} method whose parameter type matches the object type.</p>
410     *
411     * <p>This method delegates the method search to {@link #getMatchingAccessibleMethod(Class, String, Class[])}.</p>
412     *
413     * <p>This method supports calls to methods taking primitive parameters
414     * via passing in wrapping classes. So, for example, a {@code Boolean} class
415     * would match a {@code boolean} primitive.</p>
416     *
417     *
418     * @param cls invoke static method on this class
419     * @param methodName get method with this name
420     * @param args use these arguments - treat {@code null} as empty array
421     * @param parameterTypes match these parameters - treat {@code null} as empty array
422     * @return The value returned by the invoked method
423     *
424     * @throws NoSuchMethodException if there is no such accessible method
425     * @throws InvocationTargetException wraps an exception thrown by the
426     *  method invoked
427     * @throws IllegalAccessException if the requested method is not accessible
428     *  via reflection
429     */
430    public static Object invokeStaticMethod(final Class<?> cls, final String methodName,
431            Object[] args, Class<?>[] parameterTypes)
432            throws NoSuchMethodException, IllegalAccessException,
433            InvocationTargetException {
434        args = ArrayUtils.nullToEmpty(args);
435        parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
436        final Method method = getMatchingAccessibleMethod(cls, methodName,
437                parameterTypes);
438        if (method == null) {
439            throw new NoSuchMethodException("No such accessible method: "
440                    + methodName + "() on class: " + cls.getName());
441        }
442        args = toVarArgs(method, args);
443        return method.invoke(null, args);
444    }
445
446    private static Object[] toVarArgs(final Method method, Object[] args) {
447        if (method.isVarArgs()) {
448            final Class<?>[] methodParameterTypes = method.getParameterTypes();
449            args = getVarArgs(args, methodParameterTypes);
450        }
451        return args;
452    }
453
454    /**
455     * <p>Given an arguments array passed to a varargs method, return an array of arguments in the canonical form,
456     * i.e. an array with the declared number of parameters, and whose last parameter is an array of the varargs type.
457     * </p>
458     *
459     * @param args the array of arguments passed to the varags method
460     * @param methodParameterTypes the declared array of method parameter types
461     * @return an array of the variadic arguments passed to the method
462     * @since 3.5
463     */
464    static Object[] getVarArgs(final Object[] args, final Class<?>[] methodParameterTypes) {
465        if (args.length == methodParameterTypes.length
466                && args[args.length - 1].getClass().equals(methodParameterTypes[methodParameterTypes.length - 1])) {
467            // The args array is already in the canonical form for the method.
468            return args;
469        }
470
471        // Construct a new array matching the method's declared parameter types.
472        final Object[] newArgs = new Object[methodParameterTypes.length];
473
474        // Copy the normal (non-varargs) parameters
475        System.arraycopy(args, 0, newArgs, 0, methodParameterTypes.length - 1);
476
477        // Construct a new array for the variadic parameters
478        final Class<?> varArgComponentType = methodParameterTypes[methodParameterTypes.length - 1].getComponentType();
479        final int varArgLength = args.length - methodParameterTypes.length + 1;
480
481        Object varArgsArray = Array.newInstance(ClassUtils.primitiveToWrapper(varArgComponentType), varArgLength);
482        // Copy the variadic arguments into the varargs array.
483        System.arraycopy(args, methodParameterTypes.length - 1, varArgsArray, 0, varArgLength);
484
485        if(varArgComponentType.isPrimitive()) {
486            // unbox from wrapper type to primitive type
487            varArgsArray = ArrayUtils.toPrimitive(varArgsArray);
488        }
489
490        // Store the varargs array in the last position of the array to return
491        newArgs[methodParameterTypes.length - 1] = varArgsArray;
492
493        // Return the canonical varargs array.
494        return newArgs;
495    }
496
497    /**
498     * <p>Invokes a {@code static} method whose parameter types match exactly the object
499     * types.</p>
500     *
501     * <p>This uses reflection to invoke the method obtained from a call to
502     * {@link #getAccessibleMethod(Class, String, Class[])}.</p>
503     *
504     * @param cls invoke static method on this class
505     * @param methodName get method with this name
506     * @param args use these arguments - treat {@code null} as empty array
507     * @return The value returned by the invoked method
508     *
509     * @throws NoSuchMethodException if there is no such accessible method
510     * @throws InvocationTargetException wraps an exception thrown by the
511     *  method invoked
512     * @throws IllegalAccessException if the requested method is not accessible
513     *  via reflection
514     */
515    public static Object invokeExactStaticMethod(final Class<?> cls, final String methodName,
516            Object... args) throws NoSuchMethodException,
517            IllegalAccessException, InvocationTargetException {
518        args = ArrayUtils.nullToEmpty(args);
519        final Class<?>[] parameterTypes = ClassUtils.toClass(args);
520        return invokeExactStaticMethod(cls, methodName, args, parameterTypes);
521    }
522
523    /**
524     * <p>Returns an accessible method (that is, one that can be invoked via
525     * reflection) with given name and parameters. If no such method
526     * can be found, return {@code null}.
527     * This is just a convenience wrapper for
528     * {@link #getAccessibleMethod(Method)}.</p>
529     *
530     * @param cls get method from this class
531     * @param methodName get method with this name
532     * @param parameterTypes with these parameters types
533     * @return The accessible method
534     */
535    public static Method getAccessibleMethod(final Class<?> cls, final String methodName,
536            final Class<?>... parameterTypes) {
537        try {
538            return getAccessibleMethod(cls.getMethod(methodName,
539                    parameterTypes));
540        } catch (final NoSuchMethodException e) {
541            return null;
542        }
543    }
544
545    /**
546     * <p>Returns an accessible method (that is, one that can be invoked via
547     * reflection) that implements the specified Method. If no such method
548     * can be found, return {@code null}.</p>
549     *
550     * @param method The method that we wish to call
551     * @return The accessible method
552     */
553    public static Method getAccessibleMethod(Method method) {
554        if (!MemberUtils.isAccessible(method)) {
555            return null;
556        }
557        // If the declaring class is public, we are done
558        final Class<?> cls = method.getDeclaringClass();
559        if (Modifier.isPublic(cls.getModifiers())) {
560            return method;
561        }
562        final String methodName = method.getName();
563        final Class<?>[] parameterTypes = method.getParameterTypes();
564
565        // Check the implemented interfaces and subinterfaces
566        method = getAccessibleMethodFromInterfaceNest(cls, methodName,
567                parameterTypes);
568
569        // Check the superclass chain
570        if (method == null) {
571            method = getAccessibleMethodFromSuperclass(cls, methodName,
572                    parameterTypes);
573        }
574        return method;
575    }
576
577    /**
578     * <p>Returns an accessible method (that is, one that can be invoked via
579     * reflection) by scanning through the superclasses. If no such method
580     * can be found, return {@code null}.</p>
581     *
582     * @param cls Class to be checked
583     * @param methodName Method name of the method we wish to call
584     * @param parameterTypes The parameter type signatures
585     * @return the accessible method or {@code null} if not found
586     */
587    private static Method getAccessibleMethodFromSuperclass(final Class<?> cls,
588            final String methodName, final Class<?>... parameterTypes) {
589        Class<?> parentClass = cls.getSuperclass();
590        while (parentClass != null) {
591            if (Modifier.isPublic(parentClass.getModifiers())) {
592                try {
593                    return parentClass.getMethod(methodName, parameterTypes);
594                } catch (final NoSuchMethodException e) {
595                    return null;
596                }
597            }
598            parentClass = parentClass.getSuperclass();
599        }
600        return null;
601    }
602
603    /**
604     * <p>Returns an accessible method (that is, one that can be invoked via
605     * reflection) that implements the specified method, by scanning through
606     * all implemented interfaces and subinterfaces. If no such method
607     * can be found, return {@code null}.</p>
608     *
609     * <p>There isn't any good reason why this method must be {@code private}.
610     * It is because there doesn't seem any reason why other classes should
611     * call this rather than the higher level methods.</p>
612     *
613     * @param cls Parent class for the interfaces to be checked
614     * @param methodName Method name of the method we wish to call
615     * @param parameterTypes The parameter type signatures
616     * @return the accessible method or {@code null} if not found
617     */
618    private static Method getAccessibleMethodFromInterfaceNest(Class<?> cls,
619            final String methodName, final Class<?>... parameterTypes) {
620        // Search up the superclass chain
621        for (; cls != null; cls = cls.getSuperclass()) {
622
623            // Check the implemented interfaces of the parent class
624            final Class<?>[] interfaces = cls.getInterfaces();
625            for (final Class<?> anInterface : interfaces) {
626                // Is this interface public?
627                if (!Modifier.isPublic(anInterface.getModifiers())) {
628                    continue;
629                }
630                // Does the method exist on this interface?
631                try {
632                    return anInterface.getDeclaredMethod(methodName,
633                            parameterTypes);
634                } catch (final NoSuchMethodException e) { // NOPMD
635                    /*
636                     * Swallow, if no method is found after the loop then this
637                     * method returns null.
638                     */
639                }
640                // Recursively check our parent interfaces
641                final Method method = getAccessibleMethodFromInterfaceNest(anInterface,
642                        methodName, parameterTypes);
643                if (method != null) {
644                    return method;
645                }
646            }
647        }
648        return null;
649    }
650
651    /**
652     * <p>Finds an accessible method that matches the given name and has compatible parameters.
653     * Compatible parameters mean that every method parameter is assignable from
654     * the given parameters.
655     * In other words, it finds a method with the given name
656     * that will take the parameters given.</p>
657     *
658     * <p>This method is used by
659     * {@link
660     * #invokeMethod(Object object, String methodName, Object[] args, Class[] parameterTypes)}.
661     * </p>
662     *
663     * <p>This method can match primitive parameter by passing in wrapper classes.
664     * For example, a {@code Boolean} will match a primitive {@code boolean}
665     * parameter.
666     * </p>
667     *
668     * @param cls find method in this class
669     * @param methodName find method with this name
670     * @param parameterTypes find method with most compatible parameters
671     * @return The accessible method
672     */
673    public static Method getMatchingAccessibleMethod(final Class<?> cls,
674            final String methodName, final Class<?>... parameterTypes) {
675        try {
676            final Method method = cls.getMethod(methodName, parameterTypes);
677            MemberUtils.setAccessibleWorkaround(method);
678            return method;
679        } catch (final NoSuchMethodException e) { // NOPMD - Swallow the exception
680        }
681        // search through all methods
682        Method bestMatch = null;
683        final Method[] methods = cls.getMethods();
684        for (final Method method : methods) {
685            // compare name and parameters
686            if (method.getName().equals(methodName) &&
687                    MemberUtils.isMatchingMethod(method, parameterTypes)) {
688                // get accessible version of method
689                final Method accessibleMethod = getAccessibleMethod(method);
690                if (accessibleMethod != null && (bestMatch == null || MemberUtils.compareMethodFit(
691                            accessibleMethod,
692                            bestMatch,
693                            parameterTypes) < 0)) {
694                    bestMatch = accessibleMethod;
695                }
696            }
697        }
698        if (bestMatch != null) {
699            MemberUtils.setAccessibleWorkaround(bestMatch);
700        }
701
702        if (bestMatch != null && bestMatch.isVarArgs() && bestMatch.getParameterTypes().length > 0 && parameterTypes.length > 0) {
703            final Class<?>[] methodParameterTypes = bestMatch.getParameterTypes();
704            final Class<?> methodParameterComponentType = methodParameterTypes[methodParameterTypes.length - 1].getComponentType();
705            final String methodParameterComponentTypeName = ClassUtils.primitiveToWrapper(methodParameterComponentType).getName();
706            final String parameterTypeName = parameterTypes[parameterTypes.length - 1].getName();
707            final String parameterTypeSuperClassName = parameterTypes[parameterTypes.length - 1].getSuperclass().getName();
708
709            if (!methodParameterComponentTypeName.equals(parameterTypeName)
710                    && !methodParameterComponentTypeName.equals(parameterTypeSuperClassName)) {
711                return null;
712            }
713        }
714
715        return bestMatch;
716    }
717
718    /**
719     * <p>Retrieves a method whether or not it's accessible. If no such method
720     * can be found, return {@code null}.</p>
721     * @param cls The class that will be subjected to the method search
722     * @param methodName The method that we wish to call
723     * @param parameterTypes Argument class types
724     * @return The method
725     *
726     * @since 3.5
727     */
728    public static Method getMatchingMethod(final Class<?> cls, final String methodName,
729            final Class<?>... parameterTypes) {
730        Validate.notNull(cls, "Null class not allowed.");
731        Validate.notEmpty(methodName, "Null or blank methodName not allowed.");
732
733        // Address methods in superclasses
734        Method[] methodArray = cls.getDeclaredMethods();
735        final List<Class<?>> superclassList = ClassUtils.getAllSuperclasses(cls);
736        for (final Class<?> klass : superclassList) {
737            methodArray = ArrayUtils.addAll(methodArray, klass.getDeclaredMethods());
738        }
739
740        Method inexactMatch = null;
741        for (final Method method : methodArray) {
742            if (methodName.equals(method.getName()) &&
743                    Objects.deepEquals(parameterTypes, method.getParameterTypes())) {
744                return method;
745            } else if (methodName.equals(method.getName()) &&
746                    ClassUtils.isAssignable(parameterTypes, method.getParameterTypes(), true)) {
747                if (inexactMatch == null) {
748                    inexactMatch = method;
749                } else if (distance(parameterTypes, method.getParameterTypes())
750                        < distance(parameterTypes, inexactMatch.getParameterTypes())) {
751                    inexactMatch = method;
752                }
753            }
754
755        }
756        return inexactMatch;
757    }
758
759    /**
760     * <p>Returns the aggregate number of inheritance hops between assignable argument class types.  Returns -1
761     * if the arguments aren't assignable.  Fills a specific purpose for getMatchingMethod and is not generalized.</p>
762     * @param classArray
763     * @param toClassArray
764     * @return the aggregate number of inheritance hops between assignable argument class types.
765     */
766    private static int distance(final Class<?>[] classArray, final Class<?>[] toClassArray) {
767        int answer = 0;
768
769        if (!ClassUtils.isAssignable(classArray, toClassArray, true)) {
770            return -1;
771        }
772        for (int offset = 0; offset < classArray.length; offset++) {
773            // Note InheritanceUtils.distance() uses different scoring system.
774            if (classArray[offset].equals(toClassArray[offset])) {
775                continue;
776            } else if (ClassUtils.isAssignable(classArray[offset], toClassArray[offset], true)
777                    && !ClassUtils.isAssignable(classArray[offset], toClassArray[offset], false)) {
778                answer++;
779            } else {
780                answer = answer + 2;
781            }
782        }
783
784        return answer;
785    }
786
787    /**
788     * Get the hierarchy of overridden methods down to {@code result} respecting generics.
789     * @param method lowest to consider
790     * @param interfacesBehavior whether to search interfaces, {@code null} {@code implies} false
791     * @return Set&lt;Method&gt; in ascending order from sub- to superclass
792     * @throws NullPointerException if the specified method is {@code null}
793     * @since 3.2
794     */
795    public static Set<Method> getOverrideHierarchy(final Method method, final Interfaces interfacesBehavior) {
796        Validate.notNull(method);
797        final Set<Method> result = new LinkedHashSet<>();
798        result.add(method);
799
800        final Class<?>[] parameterTypes = method.getParameterTypes();
801
802        final Class<?> declaringClass = method.getDeclaringClass();
803
804        final Iterator<Class<?>> hierarchy = ClassUtils.hierarchy(declaringClass, interfacesBehavior).iterator();
805        //skip the declaring class :P
806        hierarchy.next();
807        hierarchyTraversal: while (hierarchy.hasNext()) {
808            final Class<?> c = hierarchy.next();
809            final Method m = getMatchingAccessibleMethod(c, method.getName(), parameterTypes);
810            if (m == null) {
811                continue;
812            }
813            if (Arrays.equals(m.getParameterTypes(), parameterTypes)) {
814                // matches without generics
815                result.add(m);
816                continue;
817            }
818            // necessary to get arguments every time in the case that we are including interfaces
819            final Map<TypeVariable<?>, Type> typeArguments = TypeUtils.getTypeArguments(declaringClass, m.getDeclaringClass());
820            for (int i = 0; i < parameterTypes.length; i++) {
821                final Type childType = TypeUtils.unrollVariables(typeArguments, method.getGenericParameterTypes()[i]);
822                final Type parentType = TypeUtils.unrollVariables(typeArguments, m.getGenericParameterTypes()[i]);
823                if (!TypeUtils.equals(childType, parentType)) {
824                    continue hierarchyTraversal;
825                }
826            }
827            result.add(m);
828        }
829        return result;
830    }
831
832    /**
833     * Gets all class level public methods of the given class that are annotated with the given annotation.
834     * @param cls
835     *            the {@link Class} to query
836     * @param annotationCls
837     *            the {@link java.lang.annotation.Annotation} that must be present on a method to be matched
838     * @return an array of Methods (possibly empty).
839     * @throws IllegalArgumentException
840     *            if the class or annotation are {@code null}
841     * @since 3.4
842     */
843    public static Method[] getMethodsWithAnnotation(final Class<?> cls, final Class<? extends Annotation> annotationCls) {
844        return getMethodsWithAnnotation(cls, annotationCls, false, false);
845    }
846
847    /**
848     * Gets all class level public methods of the given class that are annotated with the given annotation.
849     * @param cls
850     *            the {@link Class} to query
851     * @param annotationCls
852     *            the {@link Annotation} that must be present on a method to be matched
853     * @return a list of Methods (possibly empty).
854     * @throws IllegalArgumentException
855     *            if the class or annotation are {@code null}
856     * @since 3.4
857     */
858    public static List<Method> getMethodsListWithAnnotation(final Class<?> cls, final Class<? extends Annotation> annotationCls) {
859        return getMethodsListWithAnnotation(cls, annotationCls, false, false);
860    }
861
862    /**
863     * Gets all methods of the given class that are annotated with the given annotation.
864     * @param cls
865     *            the {@link Class} to query
866     * @param annotationCls
867     *            the {@link java.lang.annotation.Annotation} that must be present on a method to be matched
868     * @param searchSupers
869     *            determines if a lookup in the entire inheritance hierarchy of the given class should be performed
870     * @param ignoreAccess
871     *            determines if non public methods should be considered
872     * @return an array of Methods (possibly empty).
873     * @throws IllegalArgumentException
874     *            if the class or annotation are {@code null}
875     * @since 3.6
876     */
877    public static Method[] getMethodsWithAnnotation(final Class<?> cls, final Class<? extends Annotation> annotationCls,
878                                                    final boolean searchSupers, final boolean ignoreAccess) {
879        final List<Method> annotatedMethodsList = getMethodsListWithAnnotation(cls, annotationCls, searchSupers,
880                ignoreAccess);
881        return annotatedMethodsList.toArray(new Method[annotatedMethodsList.size()]);
882    }
883
884    /**
885     * Gets all methods of the given class that are annotated with the given annotation.
886     * @param cls
887     *            the {@link Class} to query
888     * @param annotationCls
889     *            the {@link Annotation} that must be present on a method to be matched
890     * @param searchSupers
891     *            determines if a lookup in the entire inheritance hierarchy of the given class should be performed
892     * @param ignoreAccess
893     *            determines if non public methods should be considered
894     * @return a list of Methods (possibly empty).
895     * @throws IllegalArgumentException
896     *            if the class or annotation are {@code null}
897     * @since 3.6
898     */
899    public static List<Method> getMethodsListWithAnnotation(final Class<?> cls,
900                                                            final Class<? extends Annotation> annotationCls,
901                                                            final boolean searchSupers, final boolean ignoreAccess) {
902
903        Validate.isTrue(cls != null, "The class must not be null");
904        Validate.isTrue(annotationCls != null, "The annotation class must not be null");
905        final List<Class<?>> classes = (searchSupers ? getAllSuperclassesAndInterfaces(cls)
906                : new ArrayList<Class<?>>());
907        classes.add(0, cls);
908        final List<Method> annotatedMethods = new ArrayList<>();
909        for (final Class<?> acls : classes) {
910            final Method[] methods = (ignoreAccess ? acls.getDeclaredMethods() : acls.getMethods());
911            for (final Method method : methods) {
912                if (method.getAnnotation(annotationCls) != null) {
913                    annotatedMethods.add(method);
914                }
915            }
916        }
917        return annotatedMethods;
918    }
919
920    /**
921     * <p>Gets the annotation object with the given annotation type that is present on the given method
922     * or optionally on any equivalent method in super classes and interfaces. Returns null if the annotation
923     * type was not present.</p>
924     *
925     * <p>Stops searching for an annotation once the first annotation of the specified type has been
926     * found. Additional annotations of the specified type will be silently ignored.</p>
927     * @param <A>
928     *            the annotation type
929     * @param method
930     *            the {@link Method} to query
931     * @param annotationCls
932     *            the {@link Annotation} to check if is present on the method
933     * @param searchSupers
934     *            determines if a lookup in the entire inheritance hierarchy of the given class is performed
935     *            if the annotation was not directly present
936     * @param ignoreAccess
937     *            determines if underlying method has to be accessible
938     * @return the first matching annotation, or {@code null} if not found
939     * @throws IllegalArgumentException
940     *            if the method or annotation are {@code null}
941     * @since 3.6
942     */
943    public static <A extends Annotation> A getAnnotation(final Method method, final Class<A> annotationCls,
944                                                         final boolean searchSupers, final boolean ignoreAccess) {
945
946        Validate.isTrue(method != null, "The method must not be null");
947        Validate.isTrue(annotationCls != null, "The annotation class must not be null");
948        if (!ignoreAccess && !MemberUtils.isAccessible(method)) {
949            return null;
950        }
951
952        A annotation = method.getAnnotation(annotationCls);
953
954        if (annotation == null && searchSupers) {
955            final Class<?> mcls = method.getDeclaringClass();
956            final List<Class<?>> classes = getAllSuperclassesAndInterfaces(mcls);
957            for (final Class<?> acls : classes) {
958                Method equivalentMethod;
959                try {
960                    equivalentMethod = (ignoreAccess ? acls.getDeclaredMethod(method.getName(), method.getParameterTypes())
961                            : acls.getMethod(method.getName(), method.getParameterTypes()));
962                } catch (final NoSuchMethodException e) {
963                    // if not found, just keep searching
964                    continue;
965                }
966                annotation = equivalentMethod.getAnnotation(annotationCls);
967                if (annotation != null) {
968                    break;
969                }
970            }
971        }
972
973        return annotation;
974    }
975
976    /**
977     * <p>Gets a combination of {@link ClassUtils#getAllSuperclasses}(Class)} and
978     * {@link ClassUtils#getAllInterfaces}(Class)}, one from superclasses, one
979     * from interfaces, and so on in a breadth first way.</p>
980     *
981     * @param cls  the class to look up, may be {@code null}
982     * @return the combined {@code List} of superclasses and interfaces in order
983     * going up from this one
984     *  {@code null} if null input
985     */
986    private static List<Class<?>> getAllSuperclassesAndInterfaces(final Class<?> cls) {
987        if (cls == null) {
988            return null;
989        }
990
991        final List<Class<?>> allSuperClassesAndInterfaces = new ArrayList<>();
992        final List<Class<?>> allSuperclasses = ClassUtils.getAllSuperclasses(cls);
993        int superClassIndex = 0;
994        final List<Class<?>> allInterfaces = ClassUtils.getAllInterfaces(cls);
995        int interfaceIndex = 0;
996        while (interfaceIndex < allInterfaces.size() ||
997                superClassIndex < allSuperclasses.size()) {
998            Class<?> acls;
999            if (interfaceIndex >= allInterfaces.size()) {
1000                acls = allSuperclasses.get(superClassIndex++);
1001            } else if (superClassIndex >= allSuperclasses.size()) {
1002                acls = allInterfaces.get(interfaceIndex++);
1003            } else if (interfaceIndex < superClassIndex) {
1004                acls = allInterfaces.get(interfaceIndex++);
1005            } else if (superClassIndex < interfaceIndex) {
1006                acls = allSuperclasses.get(superClassIndex++);
1007            } else {
1008                acls = allInterfaces.get(interfaceIndex++);
1009            }
1010            allSuperClassesAndInterfaces.add(acls);
1011        }
1012        return allSuperClassesAndInterfaces;
1013    }
1014}