org.apache.commons.lang3.reflect.MemberUtils Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of com.liferay.segments.content.targeting.upgrade
Show all versions of com.liferay.segments.content.targeting.upgrade
Liferay Segments Content Targeting Upgrade
The newest version!
/*
* 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.reflect.AccessibleObject;
import java.lang.reflect.Constructor;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import org.apache.commons.lang3.ClassUtils;
/**
* Contains common code for working with {@link java.lang.reflect.Method Methods}/{@link java.lang.reflect.Constructor Constructors},
* extracted and refactored from {@link MethodUtils} when it was imported from Commons BeanUtils.
*
* @since 2.5
*/
abstract class MemberUtils {
// TODO extract an interface to implement compareParameterSets(...)?
private static final int ACCESS_TEST = Modifier.PUBLIC | Modifier.PROTECTED | Modifier.PRIVATE;
/** Array of primitive number types ordered by "promotability" */
private static final Class[] ORDERED_PRIMITIVE_TYPES = { Byte.TYPE, Short.TYPE,
Character.TYPE, Integer.TYPE, Long.TYPE, Float.TYPE, Double.TYPE };
/**
* XXX Default access superclass workaround.
*
* When a {@code public} class has a default access superclass with {@code public} members,
* these members are accessible. Calling them from compiled code works fine.
* Unfortunately, on some JVMs, using reflection to invoke these members
* seems to (wrongly) prevent access even when the modifier is {@code public}.
* Calling {@code setAccessible(true)} solves the problem but will only work from
* sufficiently privileged code. Better workarounds would be gratefully
* accepted.
* @param o the AccessibleObject to set as accessible
* @return a boolean indicating whether the accessibility of the object was set to true.
*/
static boolean setAccessibleWorkaround(final AccessibleObject o) {
if (o == null || o.isAccessible()) {
return false;
}
final Member m = (Member) o;
if (!o.isAccessible() && Modifier.isPublic(m.getModifiers()) && isPackageAccess(m.getDeclaringClass().getModifiers())) {
try {
o.setAccessible(true);
return true;
} catch (final SecurityException e) { // NOPMD
// ignore in favor of subsequent IllegalAccessException
}
}
return false;
}
/**
* Returns whether a given set of modifiers implies package access.
* @param modifiers to test
* @return {@code true} unless {@code package}/{@code protected}/{@code private} modifier detected
*/
static boolean isPackageAccess(final int modifiers) {
return (modifiers & ACCESS_TEST) == 0;
}
/**
* Returns whether a {@link Member} is accessible.
* @param m Member to check
* @return {@code true} if m is accessible
*/
static boolean isAccessible(final Member m) {
return m != null && Modifier.isPublic(m.getModifiers()) && !m.isSynthetic();
}
/**
* Compares the relative fitness of two Constructors in terms of how well they
* match a set of runtime parameter types, such that a list ordered
* by the results of the comparison would return the best match first
* (least).
*
* @param left the "left" Constructor
* @param right the "right" Constructor
* @param actual the runtime parameter types to match against
* {@code left}/{@code right}
* @return int consistent with {@code compare} semantics
* @since 3.5
*/
static int compareConstructorFit(final Constructor left, final Constructor right, final Class[] actual) {
return compareParameterTypes(Executable.of(left), Executable.of(right), actual);
}
/**
* Compares the relative fitness of two Methods in terms of how well they
* match a set of runtime parameter types, such that a list ordered
* by the results of the comparison would return the best match first
* (least).
*
* @param left the "left" Method
* @param right the "right" Method
* @param actual the runtime parameter types to match against
* {@code left}/{@code right}
* @return int consistent with {@code compare} semantics
* @since 3.5
*/
static int compareMethodFit(final Method left, final Method right, final Class[] actual) {
return compareParameterTypes(Executable.of(left), Executable.of(right), actual);
}
/**
* Compares the relative fitness of two Executables in terms of how well they
* match a set of runtime parameter types, such that a list ordered
* by the results of the comparison would return the best match first
* (least).
*
* @param left the "left" Executable
* @param right the "right" Executable
* @param actual the runtime parameter types to match against
* {@code left}/{@code right}
* @return int consistent with {@code compare} semantics
*/
private static int compareParameterTypes(final Executable left, final Executable right, final Class[] actual) {
final float leftCost = getTotalTransformationCost(actual, left);
final float rightCost = getTotalTransformationCost(actual, right);
return leftCost < rightCost ? -1 : rightCost < leftCost ? 1 : 0;
}
/**
* Returns the sum of the object transformation cost for each class in the
* source argument list.
* @param srcArgs The source arguments
* @param executable The executable to calculate transformation costs for
* @return The total transformation cost
*/
private static float getTotalTransformationCost(final Class[] srcArgs, final Executable executable) {
final Class[] destArgs = executable.getParameterTypes();
final boolean isVarArgs = executable.isVarArgs();
// "source" and "destination" are the actual and declared args respectively.
float totalCost = 0.0f;
final long normalArgsLen = isVarArgs ? destArgs.length-1 : destArgs.length;
if (srcArgs.length < normalArgsLen) {
return Float.MAX_VALUE;
}
for (int i = 0; i < normalArgsLen; i++) {
totalCost += getObjectTransformationCost(srcArgs[i], destArgs[i]);
}
if (isVarArgs) {
// When isVarArgs is true, srcArgs and dstArgs may differ in length.
// There are two special cases to consider:
final boolean noVarArgsPassed = srcArgs.length < destArgs.length;
final boolean explicitArrayForVarags = srcArgs.length == destArgs.length && srcArgs[srcArgs.length-1].isArray();
final float varArgsCost = 0.001f;
final Class destClass = destArgs[destArgs.length-1].getComponentType();
if (noVarArgsPassed) {
// When no varargs passed, the best match is the most generic matching type, not the most specific.
totalCost += getObjectTransformationCost(destClass, Object.class) + varArgsCost;
} else if (explicitArrayForVarags) {
final Class sourceClass = srcArgs[srcArgs.length-1].getComponentType();
totalCost += getObjectTransformationCost(sourceClass, destClass) + varArgsCost;
} else {
// This is typical varargs case.
for (int i = destArgs.length-1; i < srcArgs.length; i++) {
final Class srcClass = srcArgs[i];
totalCost += getObjectTransformationCost(srcClass, destClass) + varArgsCost;
}
}
}
return totalCost;
}
/**
* Gets the number of steps required needed to turn the source class into
* the destination class. This represents the number of steps in the object
* hierarchy graph.
* @param srcClass The source class
* @param destClass The destination class
* @return The cost of transforming an object
*/
private static float getObjectTransformationCost(Class srcClass, final Class destClass) {
if (destClass.isPrimitive()) {
return getPrimitivePromotionCost(srcClass, destClass);
}
float cost = 0.0f;
while (srcClass != null && !destClass.equals(srcClass)) {
if (destClass.isInterface() && ClassUtils.isAssignable(srcClass, destClass)) {
// slight penalty for interface match.
// we still want an exact match to override an interface match,
// but
// an interface match should override anything where we have to
// get a superclass.
cost += 0.25f;
break;
}
cost++;
srcClass = srcClass.getSuperclass();
}
/*
* If the destination class is null, we've traveled all the way up to
* an Object match. We'll penalize this by adding 1.5 to the cost.
*/
if (srcClass == null) {
cost += 1.5f;
}
return cost;
}
/**
* Gets the number of steps required to promote a primitive number to another
* type.
* @param srcClass the (primitive) source class
* @param destClass the (primitive) destination class
* @return The cost of promoting the primitive
*/
private static float getPrimitivePromotionCost(final Class srcClass, final Class destClass) {
float cost = 0.0f;
Class cls = srcClass;
if (!cls.isPrimitive()) {
// slight unwrapping penalty
cost += 0.1f;
cls = ClassUtils.wrapperToPrimitive(cls);
}
for (int i = 0; cls != destClass && i < ORDERED_PRIMITIVE_TYPES.length; i++) {
if (cls == ORDERED_PRIMITIVE_TYPES[i]) {
cost += 0.1f;
if (i < ORDERED_PRIMITIVE_TYPES.length - 1) {
cls = ORDERED_PRIMITIVE_TYPES[i + 1];
}
}
}
return cost;
}
static boolean isMatchingMethod(final Method method, final Class[] parameterTypes) {
return isMatchingExecutable(Executable.of(method), parameterTypes);
}
static boolean isMatchingConstructor(final Constructor method, final Class[] parameterTypes) {
return isMatchingExecutable(Executable.of(method), parameterTypes);
}
private static boolean isMatchingExecutable(final Executable method, final Class[] parameterTypes) {
final Class[] methodParameterTypes = method.getParameterTypes();
if (ClassUtils.isAssignable(parameterTypes, methodParameterTypes, true)) {
return true;
}
if (method.isVarArgs()) {
int i;
for (i = 0; i < methodParameterTypes.length - 1 && i < parameterTypes.length; i++) {
if (!ClassUtils.isAssignable(parameterTypes[i], methodParameterTypes[i], true)) {
return false;
}
}
final Class varArgParameterType = methodParameterTypes[methodParameterTypes.length - 1].getComponentType();
for (; i < parameterTypes.length; i++) {
if (!ClassUtils.isAssignable(parameterTypes[i], varArgParameterType, true)) {
return false;
}
}
return true;
}
return false;
}
/**
* A class providing a subset of the API of java.lang.reflect.Executable in Java 1.8,
* providing a common representation for function signatures for Constructors and Methods.
*/
private static final class Executable {
private final Class[] parameterTypes;
private final boolean isVarArgs;
private static Executable of(final Method method) {
return new Executable(method);
}
private static Executable of(final Constructor constructor) {
return new Executable(constructor);
}
private Executable(final Method method) {
parameterTypes = method.getParameterTypes();
isVarArgs = method.isVarArgs();
}
private Executable(final Constructor constructor) {
parameterTypes = constructor.getParameterTypes();
isVarArgs = constructor.isVarArgs();
}
public Class[] getParameterTypes() {
return parameterTypes;
}
public boolean isVarArgs() {
return isVarArgs;
}
}
}