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Apache Commons Lang, a package of Java utility classes for the
classes that are in java.lang's hierarchy, or are considered to be so
standard as to justify existence in java.lang.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.lang3.reflect;
import java.lang.annotation.Annotation;
import java.lang.reflect.Array;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.TreeMap;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.ClassUtils;
import org.apache.commons.lang3.ClassUtils.Interfaces;
import org.apache.commons.lang3.Validate;
/**
* Utility reflection methods focused on {@link Method}s, originally from Commons BeanUtils.
* Differences from the BeanUtils version may be noted, especially where similar functionality
* already existed within Lang.
*
* Known Limitations
* Accessing Public Methods In A Default Access Superclass
* There is an issue when invoking {@code public} methods contained in a default access superclass on JREs prior to 1.4.
* Reflection locates these methods fine and correctly assigns them as {@code public}.
* However, an {@link IllegalAccessException} is thrown if the method is invoked.
*
* {@link MethodUtils} contains a workaround for this situation.
* It will attempt to call {@link java.lang.reflect.AccessibleObject#setAccessible(boolean)} on this method.
* If this call succeeds, then the method can be invoked as normal.
* This call will only succeed when the application has sufficient security privileges.
* If this call fails then the method may fail.
*
* @since 2.5
*/
public class MethodUtils {
private static final Comparator METHOD_BY_SIGNATURE = Comparator.comparing(Method::toString);
/**
* {@link MethodUtils} instances should NOT be constructed in standard programming.
* Instead, the class should be used as
* {@code MethodUtils.getAccessibleMethod(method)}.
*
* This constructor is {@code public} to permit tools that require a JavaBean
* instance to operate.
*/
public MethodUtils() {
}
/**
* Invokes a named method without parameters.
*
* This method delegates the method search to {@link #getMatchingAccessibleMethod(Class, String, Class[])}.
*
* This is a convenient wrapper for
* {@link #invokeMethod(Object object, String methodName, Object[] args, Class[] parameterTypes)}.
*
*
* @param object invoke method on this object
* @param methodName get method with this name
* @return The value returned by the invoked method
*
* @throws NoSuchMethodException if there is no such accessible method
* @throws InvocationTargetException wraps an exception thrown by the method invoked
* @throws IllegalAccessException if the requested method is not accessible via reflection
*
* @since 3.4
*/
public static Object invokeMethod(final Object object, final String methodName) throws NoSuchMethodException,
IllegalAccessException, InvocationTargetException {
return invokeMethod(object, methodName, ArrayUtils.EMPTY_OBJECT_ARRAY, null);
}
/**
* Invokes a named method without parameters.
*
* This is a convenient wrapper for
* {@link #invokeMethod(Object object, boolean forceAccess, String methodName, Object[] args, Class[] parameterTypes)}.
*
*
* @param object invoke method on this object
* @param forceAccess force access to invoke method even if it's not accessible
* @param methodName get method with this name
* @return The value returned by the invoked method
*
* @throws NoSuchMethodException if there is no such accessible method
* @throws InvocationTargetException wraps an exception thrown by the method invoked
* @throws IllegalAccessException if the requested method is not accessible via reflection
*
* @since 3.5
*/
public static Object invokeMethod(final Object object, final boolean forceAccess, final String methodName)
throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
return invokeMethod(object, forceAccess, methodName, ArrayUtils.EMPTY_OBJECT_ARRAY, null);
}
/**
* Invokes a named method whose parameter type matches the object type.
*
* This method delegates the method search to {@link #getMatchingAccessibleMethod(Class, String, Class[])}.
*
* This method supports calls to methods taking primitive parameters
* via passing in wrapping classes. So, for example, a {@link Boolean} object
* would match a {@code boolean} primitive.
*
* This is a convenient wrapper for
* {@link #invokeMethod(Object object, String methodName, Object[] args, Class[] parameterTypes)}.
*
*
* @param object invoke method on this object
* @param methodName get method with this name
* @param args use these arguments - treat null as empty array
* @return The value returned by the invoked method
*
* @throws NoSuchMethodException if there is no such accessible method
* @throws InvocationTargetException wraps an exception thrown by the method invoked
* @throws IllegalAccessException if the requested method is not accessible via reflection
* @throws NullPointerException if the object or method name are {@code null}
*/
public static Object invokeMethod(final Object object, final String methodName,
Object... args) throws NoSuchMethodException,
IllegalAccessException, InvocationTargetException {
args = ArrayUtils.nullToEmpty(args);
return invokeMethod(object, methodName, args, ClassUtils.toClass(args));
}
/**
* Invokes a named method whose parameter type matches the object type.
*
* This method supports calls to methods taking primitive parameters
* via passing in wrapping classes. So, for example, a {@link Boolean} object
* would match a {@code boolean} primitive.
*
* This is a convenient wrapper for
* {@link #invokeMethod(Object object, boolean forceAccess, String methodName, Object[] args, Class[] parameterTypes)}.
*
*
* @param object invoke method on this object
* @param forceAccess force access to invoke method even if it's not accessible
* @param methodName get method with this name
* @param args use these arguments - treat null as empty array
* @return The value returned by the invoked method
*
* @throws NoSuchMethodException if there is no such accessible method
* @throws InvocationTargetException wraps an exception thrown by the method invoked
* @throws IllegalAccessException if the requested method is not accessible via reflection
* @throws NullPointerException if the object or method name are {@code null}
* @since 3.5
*/
public static Object invokeMethod(final Object object, final boolean forceAccess, final String methodName,
Object... args) throws NoSuchMethodException,
IllegalAccessException, InvocationTargetException {
args = ArrayUtils.nullToEmpty(args);
return invokeMethod(object, forceAccess, methodName, args, ClassUtils.toClass(args));
}
/**
* Invokes a named method whose parameter type matches the object type.
*
* This method supports calls to methods taking primitive parameters
* via passing in wrapping classes. So, for example, a {@link Boolean} object
* would match a {@code boolean} primitive.
*
* @param object invoke method on this object
* @param forceAccess force access to invoke method even if it's not accessible
* @param methodName get method with this name
* @param args use these arguments - treat null as empty array
* @param parameterTypes match these parameters - treat null as empty array
* @return The value returned by the invoked method
*
* @throws NoSuchMethodException if there is no such accessible method
* @throws InvocationTargetException wraps an exception thrown by the method invoked
* @throws IllegalAccessException if the requested method is not accessible via reflection
* @throws NullPointerException if the object or method name are {@code null}
* @since 3.5
*/
public static Object invokeMethod(final Object object, final boolean forceAccess, final String methodName, Object[] args, Class[] parameterTypes)
throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
Objects.requireNonNull(object, "object");
parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
args = ArrayUtils.nullToEmpty(args);
final String messagePrefix;
final Method method;
final Class cls = object.getClass();
if (forceAccess) {
messagePrefix = "No such method: ";
method = getMatchingMethod(cls, methodName, parameterTypes);
if (method != null && !method.isAccessible()) {
method.setAccessible(true);
}
} else {
messagePrefix = "No such accessible method: ";
method = getMatchingAccessibleMethod(cls, methodName, parameterTypes);
}
if (method == null) {
throw new NoSuchMethodException(messagePrefix + methodName + "() on object: " + cls.getName());
}
args = toVarArgs(method, args);
return method.invoke(object, args);
}
/**
* Invokes a named method whose parameter type matches the object type.
*
* This method delegates the method search to {@link #getMatchingAccessibleMethod(Class, String, Class[])}.
*
* This method supports calls to methods taking primitive parameters
* via passing in wrapping classes. So, for example, a {@link Boolean} object
* would match a {@code boolean} primitive.
*
* @param object invoke method on this object
* @param methodName get method with this name
* @param args use these arguments - treat null as empty array
* @param parameterTypes match these parameters - treat null as empty array
* @return The value returned by the invoked method
*
* @throws NoSuchMethodException if there is no such accessible method
* @throws InvocationTargetException wraps an exception thrown by the method invoked
* @throws IllegalAccessException if the requested method is not accessible via reflection
*/
public static Object invokeMethod(final Object object, final String methodName,
final Object[] args, final Class[] parameterTypes)
throws NoSuchMethodException, IllegalAccessException,
InvocationTargetException {
return invokeMethod(object, false, methodName, args, parameterTypes);
}
/**
* Invokes a method whose parameter types match exactly the object
* types.
*
* This uses reflection to invoke the method obtained from a call to
* {@link #getAccessibleMethod}(Class, String, Class[])}.
*
* @param object invoke method on this object
* @param methodName get method with this name
* @return The value returned by the invoked method
*
* @throws NoSuchMethodException if there is no such accessible method
* @throws InvocationTargetException wraps an exception thrown by the
* method invoked
* @throws IllegalAccessException if the requested method is not accessible
* via reflection
*
* @since 3.4
*/
public static Object invokeExactMethod(final Object object, final String methodName) throws NoSuchMethodException,
IllegalAccessException, InvocationTargetException {
return invokeExactMethod(object, methodName, ArrayUtils.EMPTY_OBJECT_ARRAY, null);
}
/**
* Invokes a method with no parameters.
*
* This uses reflection to invoke the method obtained from a call to
* {@link #getAccessibleMethod}(Class, String, Class[])}.
*
* @param object invoke method on this object
* @param methodName get method with this name
* @param args use these arguments - treat null as empty array
* @return The value returned by the invoked method
*
* @throws NoSuchMethodException if there is no such accessible method
* @throws InvocationTargetException wraps an exception thrown by the
* method invoked
* @throws IllegalAccessException if the requested method is not accessible
* via reflection
* @throws NullPointerException if the object or method name are {@code null}
*/
public static Object invokeExactMethod(final Object object, final String methodName,
Object... args) throws NoSuchMethodException,
IllegalAccessException, InvocationTargetException {
args = ArrayUtils.nullToEmpty(args);
return invokeExactMethod(object, methodName, args, ClassUtils.toClass(args));
}
/**
* Invokes a method whose parameter types match exactly the parameter
* types given.
*
* This uses reflection to invoke the method obtained from a call to
* {@link #getAccessibleMethod(Class, String, Class[])}.
*
* @param object invoke method on this object
* @param methodName get method with this name
* @param args use these arguments - treat null as empty array
* @param parameterTypes match these parameters - treat {@code null} as empty array
* @return The value returned by the invoked method
*
* @throws NoSuchMethodException if there is no such accessible method
* @throws InvocationTargetException wraps an exception thrown by the
* method invoked
* @throws IllegalAccessException if the requested method is not accessible
* via reflection
* @throws NullPointerException if the object or method name are {@code null}
*/
public static Object invokeExactMethod(final Object object, final String methodName, Object[] args, Class[] parameterTypes)
throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
Objects.requireNonNull(object, "object");
args = ArrayUtils.nullToEmpty(args);
parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
final Class cls = object.getClass();
final Method method = getAccessibleMethod(cls, methodName, parameterTypes);
if (method == null) {
throw new NoSuchMethodException("No such accessible method: " + methodName + "() on object: " + cls.getName());
}
return method.invoke(object, args);
}
/**
* Invokes a {@code static} method whose parameter types match exactly the parameter
* types given.
*
* This uses reflection to invoke the method obtained from a call to
* {@link #getAccessibleMethod(Class, String, Class[])}.
*
* @param cls invoke static method on this class
* @param methodName get method with this name
* @param args use these arguments - treat {@code null} as empty array
* @param parameterTypes match these parameters - treat {@code null} as empty array
* @return The value returned by the invoked method
*
* @throws NoSuchMethodException if there is no such accessible method
* @throws InvocationTargetException wraps an exception thrown by the
* method invoked
* @throws IllegalAccessException if the requested method is not accessible
* via reflection
*/
public static Object invokeExactStaticMethod(final Class cls, final String methodName,
Object[] args, Class[] parameterTypes)
throws NoSuchMethodException, IllegalAccessException,
InvocationTargetException {
args = ArrayUtils.nullToEmpty(args);
parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
final Method method = getAccessibleMethod(cls, methodName, parameterTypes);
if (method == null) {
throw new NoSuchMethodException("No such accessible method: "
+ methodName + "() on class: " + cls.getName());
}
return method.invoke(null, args);
}
/**
* Invokes a named {@code static} method whose parameter type matches the object type.
*
* This method delegates the method search to {@link #getMatchingAccessibleMethod(Class, String, Class[])}.
*
* This method supports calls to methods taking primitive parameters
* via passing in wrapping classes. So, for example, a {@link Boolean} class
* would match a {@code boolean} primitive.
*
* This is a convenient wrapper for
* {@link #invokeStaticMethod(Class, String, Object[], Class[])}.
*
*
* @param cls invoke static method on this class
* @param methodName get method with this name
* @param args use these arguments - treat {@code null} as empty array
* @return The value returned by the invoked method
*
* @throws NoSuchMethodException if there is no such accessible method
* @throws InvocationTargetException wraps an exception thrown by the
* method invoked
* @throws IllegalAccessException if the requested method is not accessible
* via reflection
*/
public static Object invokeStaticMethod(final Class cls, final String methodName,
Object... args) throws NoSuchMethodException,
IllegalAccessException, InvocationTargetException {
args = ArrayUtils.nullToEmpty(args);
return invokeStaticMethod(cls, methodName, args, ClassUtils.toClass(args));
}
/**
* Invokes a named {@code static} method whose parameter type matches the object type.
*
* This method delegates the method search to {@link #getMatchingAccessibleMethod(Class, String, Class[])}.
*
* This method supports calls to methods taking primitive parameters
* via passing in wrapping classes. So, for example, a {@link Boolean} class
* would match a {@code boolean} primitive.
*
* @param cls invoke static method on this class
* @param methodName get method with this name
* @param args use these arguments - treat {@code null} as empty array
* @param parameterTypes match these parameters - treat {@code null} as empty array
* @return The value returned by the invoked method
*
* @throws NoSuchMethodException if there is no such accessible method
* @throws InvocationTargetException wraps an exception thrown by the
* method invoked
* @throws IllegalAccessException if the requested method is not accessible
* via reflection
*/
public static Object invokeStaticMethod(final Class cls, final String methodName,
Object[] args, Class[] parameterTypes)
throws NoSuchMethodException, IllegalAccessException,
InvocationTargetException {
args = ArrayUtils.nullToEmpty(args);
parameterTypes = ArrayUtils.nullToEmpty(parameterTypes);
final Method method = getMatchingAccessibleMethod(cls, methodName,
parameterTypes);
if (method == null) {
throw new NoSuchMethodException("No such accessible method: "
+ methodName + "() on class: " + cls.getName());
}
args = toVarArgs(method, args);
return method.invoke(null, args);
}
private static Object[] toVarArgs(final Method method, Object[] args) {
if (method.isVarArgs()) {
final Class[] methodParameterTypes = method.getParameterTypes();
args = getVarArgs(args, methodParameterTypes);
}
return args;
}
/**
* Given an arguments array passed to a varargs method, return an array of arguments in the canonical form,
* i.e. an array with the declared number of parameters, and whose last parameter is an array of the varargs type.
*
* @param args the array of arguments passed to the varags method
* @param methodParameterTypes the declared array of method parameter types
* @return an array of the variadic arguments passed to the method
* @since 3.5
*/
static Object[] getVarArgs(final Object[] args, final Class[] methodParameterTypes) {
if (args.length == methodParameterTypes.length && (args[args.length - 1] == null ||
args[args.length - 1].getClass().equals(methodParameterTypes[methodParameterTypes.length - 1]))) {
// The args array is already in the canonical form for the method.
return args;
}
// Construct a new array matching the method's declared parameter types.
final Object[] newArgs = new Object[methodParameterTypes.length];
// Copy the normal (non-varargs) parameters
System.arraycopy(args, 0, newArgs, 0, methodParameterTypes.length - 1);
// Construct a new array for the variadic parameters
final Class varArgComponentType = methodParameterTypes[methodParameterTypes.length - 1].getComponentType();
final int varArgLength = args.length - methodParameterTypes.length + 1;
Object varArgsArray = Array.newInstance(ClassUtils.primitiveToWrapper(varArgComponentType), varArgLength);
// Copy the variadic arguments into the varargs array.
System.arraycopy(args, methodParameterTypes.length - 1, varArgsArray, 0, varArgLength);
if (varArgComponentType.isPrimitive()) {
// unbox from wrapper type to primitive type
varArgsArray = ArrayUtils.toPrimitive(varArgsArray);
}
// Store the varargs array in the last position of the array to return
newArgs[methodParameterTypes.length - 1] = varArgsArray;
// Return the canonical varargs array.
return newArgs;
}
/**
* Invokes a {@code static} method whose parameter types match exactly the object
* types.
*
* This uses reflection to invoke the method obtained from a call to
* {@link #getAccessibleMethod(Class, String, Class[])}.
*
* @param cls invoke static method on this class
* @param methodName get method with this name
* @param args use these arguments - treat {@code null} as empty array
* @return The value returned by the invoked method
*
* @throws NoSuchMethodException if there is no such accessible method
* @throws InvocationTargetException wraps an exception thrown by the
* method invoked
* @throws IllegalAccessException if the requested method is not accessible
* via reflection
*/
public static Object invokeExactStaticMethod(final Class cls, final String methodName,
Object... args) throws NoSuchMethodException,
IllegalAccessException, InvocationTargetException {
args = ArrayUtils.nullToEmpty(args);
return invokeExactStaticMethod(cls, methodName, args, ClassUtils.toClass(args));
}
/**
* Returns an accessible method (that is, one that can be invoked via
* reflection) with given name and parameters. If no such method
* can be found, return {@code null}.
* This is just a convenience wrapper for
* {@link #getAccessibleMethod(Method)}.
*
* @param cls get method from this class
* @param methodName get method with this name
* @param parameterTypes with these parameters types
* @return The accessible method
*/
public static Method getAccessibleMethod(final Class cls, final String methodName,
final Class... parameterTypes) {
try {
return getAccessibleMethod(cls.getMethod(methodName, parameterTypes));
} catch (final NoSuchMethodException e) {
return null;
}
}
/**
* Returns an accessible method (that is, one that can be invoked via
* reflection) that implements the specified Method. If no such method
* can be found, return {@code null}.
*
* @param method The method that we wish to call
* @return The accessible method
*/
public static Method getAccessibleMethod(Method method) {
if (!MemberUtils.isAccessible(method)) {
return null;
}
// If the declaring class is public, we are done
final Class cls = method.getDeclaringClass();
if (ClassUtils.isPublic(cls)) {
return method;
}
final String methodName = method.getName();
final Class[] parameterTypes = method.getParameterTypes();
// Check the implemented interfaces and subinterfaces
method = getAccessibleMethodFromInterfaceNest(cls, methodName,
parameterTypes);
// Check the superclass chain
if (method == null) {
method = getAccessibleMethodFromSuperclass(cls, methodName,
parameterTypes);
}
return method;
}
/**
* Returns an accessible method (that is, one that can be invoked via
* reflection) by scanning through the superclasses. If no such method
* can be found, return {@code null}.
*
* @param cls Class to be checked
* @param methodName Method name of the method we wish to call
* @param parameterTypes The parameter type signatures
* @return the accessible method or {@code null} if not found
*/
private static Method getAccessibleMethodFromSuperclass(final Class cls,
final String methodName, final Class... parameterTypes) {
Class parentClass = cls.getSuperclass();
while (parentClass != null) {
if (ClassUtils.isPublic(parentClass)) {
try {
return parentClass.getMethod(methodName, parameterTypes);
} catch (final NoSuchMethodException e) {
return null;
}
}
parentClass = parentClass.getSuperclass();
}
return null;
}
/**
* Returns an accessible method (that is, one that can be invoked via
* reflection) that implements the specified method, by scanning through
* all implemented interfaces and subinterfaces. If no such method
* can be found, return {@code null}.
*
* There isn't any good reason why this method must be {@code private}.
* It is because there doesn't seem any reason why other classes should
* call this rather than the higher level methods.
*
* @param cls Parent class for the interfaces to be checked
* @param methodName Method name of the method we wish to call
* @param parameterTypes The parameter type signatures
* @return the accessible method or {@code null} if not found
*/
private static Method getAccessibleMethodFromInterfaceNest(Class cls,
final String methodName, final Class... parameterTypes) {
// Search up the superclass chain
for (; cls != null; cls = cls.getSuperclass()) {
// Check the implemented interfaces of the parent class
final Class[] interfaces = cls.getInterfaces();
for (final Class anInterface : interfaces) {
// Is this interface public?
if (!ClassUtils.isPublic(anInterface)) {
continue;
}
// Does the method exist on this interface?
try {
return anInterface.getDeclaredMethod(methodName,
parameterTypes);
} catch (final NoSuchMethodException ignored) {
/*
* Swallow, if no method is found after the loop then this
* method returns null.
*/
}
// Recursively check our parent interfaces
final Method method = getAccessibleMethodFromInterfaceNest(anInterface,
methodName, parameterTypes);
if (method != null) {
return method;
}
}
}
return null;
}
/**
* Finds an accessible method that matches the given name and has compatible parameters.
* Compatible parameters mean that every method parameter is assignable from
* the given parameters.
* In other words, it finds a method with the given name
* that will take the parameters given.
*
* This method is used by
* {@link
* #invokeMethod(Object object, String methodName, Object[] args, Class[] parameterTypes)}.
*
*
* This method can match primitive parameter by passing in wrapper classes.
* For example, a {@link Boolean} will match a primitive {@code boolean}
* parameter.
*
*
* @param cls find method in this class
* @param methodName find method with this name
* @param parameterTypes find method with most compatible parameters
* @return The accessible method
*/
public static Method getMatchingAccessibleMethod(final Class cls,
final String methodName, final Class... parameterTypes) {
try {
return MemberUtils.setAccessibleWorkaround(cls.getMethod(methodName, parameterTypes));
} catch (final NoSuchMethodException ignored) {
// Swallow the exception
}
// search through all methods
final Method[] methods = cls.getMethods();
final List matchingMethods = Stream.of(methods)
.filter(method -> method.getName().equals(methodName) && MemberUtils.isMatchingMethod(method, parameterTypes)).collect(Collectors.toList());
// Sort methods by signature to force deterministic result
matchingMethods.sort(METHOD_BY_SIGNATURE);
Method bestMatch = null;
for (final Method method : matchingMethods) {
// get accessible version of method
final Method accessibleMethod = getAccessibleMethod(method);
if (accessibleMethod != null && (bestMatch == null || MemberUtils.compareMethodFit(accessibleMethod, bestMatch, parameterTypes) < 0)) {
bestMatch = accessibleMethod;
}
}
if (bestMatch != null) {
MemberUtils.setAccessibleWorkaround(bestMatch);
}
if (bestMatch != null && bestMatch.isVarArgs() && bestMatch.getParameterTypes().length > 0 && parameterTypes.length > 0) {
final Class[] methodParameterTypes = bestMatch.getParameterTypes();
final Class methodParameterComponentType = methodParameterTypes[methodParameterTypes.length - 1].getComponentType();
final String methodParameterComponentTypeName = ClassUtils.primitiveToWrapper(methodParameterComponentType).getName();
final Class lastParameterType = parameterTypes[parameterTypes.length - 1];
final String parameterTypeName = lastParameterType == null ? null : lastParameterType.getName();
final String parameterTypeSuperClassName = lastParameterType == null ? null : lastParameterType.getSuperclass().getName();
if (parameterTypeName != null && parameterTypeSuperClassName != null && !methodParameterComponentTypeName.equals(parameterTypeName)
&& !methodParameterComponentTypeName.equals(parameterTypeSuperClassName)) {
return null;
}
}
return bestMatch;
}
/**
* Retrieves a method whether or not it's accessible. If no such method
* can be found, return {@code null}.
* @param cls The class that will be subjected to the method search
* @param methodName The method that we wish to call
* @param parameterTypes Argument class types
* @throws IllegalStateException if there is no unique result
* @throws NullPointerException if the class is {@code null}
* @return The method
*
* @since 3.5
*/
public static Method getMatchingMethod(final Class cls, final String methodName,
final Class... parameterTypes) {
Objects.requireNonNull(cls, "cls");
Validate.notEmpty(methodName, "methodName");
final List methods = Stream.of(cls.getDeclaredMethods())
.filter(method -> method.getName().equals(methodName))
.collect(Collectors.toList());
ClassUtils.getAllSuperclasses(cls).stream()
.map(Class::getDeclaredMethods)
.flatMap(Stream::of)
.filter(method -> method.getName().equals(methodName))
.forEach(methods::add);
for (final Method method : methods) {
if (Arrays.deepEquals(method.getParameterTypes(), parameterTypes)) {
return method;
}
}
final TreeMap> candidates = new TreeMap<>();
methods.stream()
.filter(method -> ClassUtils.isAssignable(parameterTypes, method.getParameterTypes(), true))
.forEach(method -> {
final int distance = distance(parameterTypes, method.getParameterTypes());
final List candidatesAtDistance = candidates.computeIfAbsent(distance, k -> new ArrayList<>());
candidatesAtDistance.add(method);
});
if (candidates.isEmpty()) {
return null;
}
final List bestCandidates = candidates.values().iterator().next();
if (bestCandidates.size() == 1 || !Objects.equals(bestCandidates.get(0).getDeclaringClass(),
bestCandidates.get(1).getDeclaringClass())) {
return bestCandidates.get(0);
}
throw new IllegalStateException(
String.format("Found multiple candidates for method %s on class %s : %s",
methodName + Stream.of(parameterTypes).map(String::valueOf).collect(Collectors.joining(",", "(", ")")),
cls.getName(),
bestCandidates.stream().map(Method::toString).collect(Collectors.joining(",", "[", "]")))
);
}
/**
* Returns the aggregate number of inheritance hops between assignable argument class types. Returns -1
* if the arguments aren't assignable. Fills a specific purpose for getMatchingMethod and is not generalized.
* @param fromClassArray the Class array to calculate the distance from.
* @param toClassArray the Class array to calculate the distance to.
* @return the aggregate number of inheritance hops between assignable argument class types.
*/
private static int distance(final Class[] fromClassArray, final Class[] toClassArray) {
int answer = 0;
if (!ClassUtils.isAssignable(fromClassArray, toClassArray, true)) {
return -1;
}
for (int offset = 0; offset < fromClassArray.length; offset++) {
// Note InheritanceUtils.distance() uses different scoring system.
final Class aClass = fromClassArray[offset];
final Class toClass = toClassArray[offset];
if (aClass == null || aClass.equals(toClass)) {
continue;
}
if (ClassUtils.isAssignable(aClass, toClass, true)
&& !ClassUtils.isAssignable(aClass, toClass, false)) {
answer++;
} else {
answer = answer + 2;
}
}
return answer;
}
/**
* Gets the hierarchy of overridden methods down to {@code result} respecting generics.
* @param method lowest to consider
* @param interfacesBehavior whether to search interfaces, {@code null} {@code implies} false
* @return Set<Method> in ascending order from sub- to superclass
* @throws NullPointerException if the specified method is {@code null}
* @since 3.2
*/
public static Set getOverrideHierarchy(final Method method, final Interfaces interfacesBehavior) {
Objects.requireNonNull(method, "method");
final Set result = new LinkedHashSet<>();
result.add(method);
final Class[] parameterTypes = method.getParameterTypes();
final Class declaringClass = method.getDeclaringClass();
final Iterator> hierarchy = ClassUtils.hierarchy(declaringClass, interfacesBehavior).iterator();
//skip the declaring class :P
hierarchy.next();
hierarchyTraversal: while (hierarchy.hasNext()) {
final Class c = hierarchy.next();
final Method m = getMatchingAccessibleMethod(c, method.getName(), parameterTypes);
if (m == null) {
continue;
}
if (Arrays.equals(m.getParameterTypes(), parameterTypes)) {
// matches without generics
result.add(m);
continue;
}
// necessary to get arguments every time in the case that we are including interfaces
final Map, Type> typeArguments = TypeUtils.getTypeArguments(declaringClass, m.getDeclaringClass());
for (int i = 0; i < parameterTypes.length; i++) {
final Type childType = TypeUtils.unrollVariables(typeArguments, method.getGenericParameterTypes()[i]);
final Type parentType = TypeUtils.unrollVariables(typeArguments, m.getGenericParameterTypes()[i]);
if (!TypeUtils.equals(childType, parentType)) {
continue hierarchyTraversal;
}
}
result.add(m);
}
return result;
}
/**
* Gets all class level public methods of the given class that are annotated with the given annotation.
* @param cls
* the {@link Class} to query
* @param annotationCls
* the {@link java.lang.annotation.Annotation} that must be present on a method to be matched
* @return an array of Methods (possibly empty).
* @throws NullPointerException if the class or annotation are {@code null}
* @since 3.4
*/
public static Method[] getMethodsWithAnnotation(final Class cls, final Class annotationCls) {
return getMethodsWithAnnotation(cls, annotationCls, false, false);
}
/**
* Gets all class level public methods of the given class that are annotated with the given annotation.
* @param cls
* the {@link Class} to query
* @param annotationCls
* the {@link Annotation} that must be present on a method to be matched
* @return a list of Methods (possibly empty).
* @throws NullPointerException
* if the class or annotation are {@code null}
* @since 3.4
*/
public static List getMethodsListWithAnnotation(final Class cls, final Class annotationCls) {
return getMethodsListWithAnnotation(cls, annotationCls, false, false);
}
/**
* Gets all methods of the given class that are annotated with the given annotation.
* @param cls
* the {@link Class} to query
* @param annotationCls
* the {@link java.lang.annotation.Annotation} that must be present on a method to be matched
* @param searchSupers
* determines if a lookup in the entire inheritance hierarchy of the given class should be performed
* @param ignoreAccess
* determines if non-public methods should be considered
* @return an array of Methods (possibly empty).
* @throws NullPointerException if the class or annotation are {@code null}
* @since 3.6
*/
public static Method[] getMethodsWithAnnotation(final Class cls, final Class annotationCls,
final boolean searchSupers, final boolean ignoreAccess) {
return getMethodsListWithAnnotation(cls, annotationCls, searchSupers, ignoreAccess).toArray(ArrayUtils.EMPTY_METHOD_ARRAY);
}
/**
* Gets all methods of the given class that are annotated with the given annotation.
* @param cls
* the {@link Class} to query
* @param annotationCls
* the {@link Annotation} that must be present on a method to be matched
* @param searchSupers
* determines if a lookup in the entire inheritance hierarchy of the given class should be performed
* @param ignoreAccess
* determines if non-public methods should be considered
* @return a list of Methods (possibly empty).
* @throws NullPointerException if either the class or annotation class is {@code null}
* @since 3.6
*/
public static List getMethodsListWithAnnotation(final Class cls,
final Class annotationCls,
final boolean searchSupers, final boolean ignoreAccess) {
Objects.requireNonNull(cls, "cls");
Objects.requireNonNull(annotationCls, "annotationCls");
final List> classes = searchSupers ? getAllSuperclassesAndInterfaces(cls) : new ArrayList<>();
classes.add(0, cls);
final List annotatedMethods = new ArrayList<>();
classes.forEach(acls -> {
final Method[] methods = ignoreAccess ? acls.getDeclaredMethods() : acls.getMethods();
Stream.of(methods).filter(method -> method.isAnnotationPresent(annotationCls)).forEachOrdered(annotatedMethods::add);
});
return annotatedMethods;
}
/**
* Gets the annotation object with the given annotation type that is present on the given method
* or optionally on any equivalent method in super classes and interfaces. Returns null if the annotation
* type was not present.
*
* Stops searching for an annotation once the first annotation of the specified type has been
* found. Additional annotations of the specified type will be silently ignored.
* @param
* the annotation type
* @param method
* the {@link Method} to query
* @param annotationCls
* the {@link Annotation} to check if is present on the method
* @param searchSupers
* determines if a lookup in the entire inheritance hierarchy of the given class is performed
* if the annotation was not directly present
* @param ignoreAccess
* determines if underlying method has to be accessible
* @return the first matching annotation, or {@code null} if not found
* @throws NullPointerException if either the method or annotation class is {@code null}
* @since 3.6
*/
public static A getAnnotation(final Method method, final Class annotationCls,
final boolean searchSupers, final boolean ignoreAccess) {
Objects.requireNonNull(method, "method");
Objects.requireNonNull(annotationCls, "annotationCls");
if (!ignoreAccess && !MemberUtils.isAccessible(method)) {
return null;
}
A annotation = method.getAnnotation(annotationCls);
if (annotation == null && searchSupers) {
final Class mcls = method.getDeclaringClass();
final List> classes = getAllSuperclassesAndInterfaces(mcls);
for (final Class acls : classes) {
final Method equivalentMethod = ignoreAccess ? MethodUtils.getMatchingMethod(acls, method.getName(), method.getParameterTypes())
: MethodUtils.getMatchingAccessibleMethod(acls, method.getName(), method.getParameterTypes());
if (equivalentMethod != null) {
annotation = equivalentMethod.getAnnotation(annotationCls);
if (annotation != null) {
break;
}
}
}
}
return annotation;
}
/**
* Gets a combination of {@link ClassUtils#getAllSuperclasses(Class)} and
* {@link ClassUtils#getAllInterfaces(Class)}, one from superclasses, one
* from interfaces, and so on in a breadth first way.
*
* @param cls the class to look up, may be {@code null}
* @return the combined {@link List} of superclasses and interfaces in order
* going up from this one
* {@code null} if null input
*/
private static List> getAllSuperclassesAndInterfaces(final Class cls) {
if (cls == null) {
return null;
}
final List> allSuperClassesAndInterfaces = new ArrayList<>();
final List> allSuperclasses = ClassUtils.getAllSuperclasses(cls);
int superClassIndex = 0;
final List> allInterfaces = ClassUtils.getAllInterfaces(cls);
int interfaceIndex = 0;
while (interfaceIndex < allInterfaces.size() ||
superClassIndex < allSuperclasses.size()) {
final Class acls;
if (interfaceIndex >= allInterfaces.size()) {
acls = allSuperclasses.get(superClassIndex++);
} else if (superClassIndex >= allSuperclasses.size() || !(superClassIndex < interfaceIndex)) {
acls = allInterfaces.get(interfaceIndex++);
} else {
acls = allSuperclasses.get(superClassIndex++);
}
allSuperClassesAndInterfaces.add(acls);
}
return allSuperClassesAndInterfaces;
}
}