/*
* Copyright 2012 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* 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.gradle.internal.reflect;
import org.gradle.api.JavaVersion;
import org.gradle.api.specs.Spec;
import org.gradle.internal.Cast;
import org.gradle.internal.Factory;
import org.gradle.internal.UncheckedException;
import org.gradle.util.CollectionUtils;
import java.lang.annotation.Annotation;
import java.lang.annotation.Inherited;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;
import java.util.WeakHashMap;
public class JavaReflectionUtil {
private static final WeakHashMap<Class<?>, Set<String>> PROPERTY_CACHE = new WeakHashMap<Class<?>, Set<String>>();
/**
* Locates the property with the given name as a readable property. Searches only public properties.
*
* @throws NoSuchPropertyException when the given property does not exist.
*/
public static <T, F> PropertyAccessor<T, F> readableProperty(Class<T> target, Class<F> returnType, String property) throws NoSuchPropertyException {
final Method getterMethod = findGetterMethod(target, property);
if (getterMethod == null) {
throw new NoSuchPropertyException(String.format("Could not find getter method for property '%s' on class %s.", property, target.getSimpleName()));
}
return new GetterMethodBackedPropertyAccessor<T, F>(property, returnType, getterMethod);
}
/**
* Locates the property with the given name as a readable property. Searches only public properties.
*
* @throws NoSuchPropertyException when the given property does not exist.
*/
public static <T, F> PropertyAccessor<T, F> readableProperty(T target, Class<F> returnType, String property) throws NoSuchPropertyException {
@SuppressWarnings("unchecked")
Class<T> targetClass = (Class<T>) target.getClass();
return readableProperty(targetClass, returnType, property);
}
/**
* Locates the field with the given name as a readable property. Searches only public fields.
*/
public static <T, F> PropertyAccessor<T, F> readableField(Class<T> target, Class<F> fieldType, String fieldName) throws NoSuchPropertyException {
Field field = findField(target, fieldName);
if (field == null) {
throw new NoSuchPropertyException(String.format("Could not find field '%s' on class %s.", fieldName, target.getSimpleName()));
}
return new FieldBackedPropertyAccessor<T, F>(fieldName, fieldType, field);
}
/**
* Locates the field with the given name as a readable property. Searches only public fields.
*/
public static <T, F> PropertyAccessor<T, F> readableField(T target, Class<F> fieldType, String fieldName) throws NoSuchPropertyException {
@SuppressWarnings("unchecked")
Class<T> targetClass = (Class<T>) target.getClass();
return readableField(targetClass, fieldType, fieldName);
}
private static Method findGetterMethod(Class<?> target, String property) {
Method[] methods = target.getMethods();
String getter = toMethodName("get", property);
String iser = toMethodName("is", property);
for (Method method : methods) {
String methodName = method.getName();
if (getter.equals(methodName) && PropertyAccessorType.of(method) == PropertyAccessorType.GET_GETTER) {
return method;
}
if (iser.equals(methodName) && PropertyAccessorType.of(method) == PropertyAccessorType.IS_GETTER) {
return method;
}
}
return null;
}
/**
* Locates the property with the given name as a writable property. Searches only public properties.
*
* @throws NoSuchPropertyException when the given property does not exist.
*/
public static PropertyMutator writeableProperty(Class<?> target, String property) throws NoSuchPropertyException {
PropertyMutator mutator = writeablePropertyIfExists(target, property);
if (mutator != null) {
return mutator;
}
throw new NoSuchPropertyException(String.format("Could not find setter method for property '%s' on class %s.", property, target.getSimpleName()));
}
/**
* Locates the property with the given name as a writable property. Searches only public properties.
*
* Returns null if no such property exists.
*/
public static PropertyMutator writeablePropertyIfExists(Class<?> target, String property) throws NoSuchPropertyException {
String setterName = toMethodName("set", property);
for (final Method method : target.getMethods()) {
if (!method.getName().equals(setterName) || PropertyAccessorType.of(method) != PropertyAccessorType.SETTER) {
continue;
}
return new MethodBackedPropertyMutator(property, method);
}
return null;
}
/**
* Locates the field with the given name as a writable property. Searches only public properties.
*
* @throws NoSuchPropertyException when the given property does not exist.
*/
public static PropertyMutator writeableField(Class<?> target, String fieldName) throws NoSuchPropertyException {
Field field = findField(target, fieldName);
if (field != null) {
return new FieldBackedPropertyMutator(fieldName, field);
}
throw new NoSuchPropertyException(String.format("Could not find writeable field '%s' on class %s.", fieldName, target.getSimpleName()));
}
private static Field findField(Class<?> target, String fieldName) {
Field[] fields = target.getFields();
for (Field field : fields) {
if (fieldName.equals(field.getName())) {
return field;
}
}
return null;
}
private static String toMethodName(String prefix, String propertyName) {
return prefix + Character.toUpperCase(propertyName.charAt(0)) + propertyName.substring(1);
}
public static Class<?> getWrapperTypeForPrimitiveType(Class<?> type) {
if (type == Character.TYPE) {
return Character.class;
} else if (type == Boolean.TYPE) {
return Boolean.class;
} else if (type == Long.TYPE) {
return Long.class;
} else if (type == Integer.TYPE) {
return Integer.class;
} else if (type == Short.TYPE) {
return Short.class;
} else if (type == Byte.TYPE) {
return Byte.class;
} else if (type == Float.TYPE) {
return Float.class;
} else if (type == Double.TYPE) {
return Double.class;
}
throw new IllegalArgumentException(String.format("Don't know the wrapper type for primitive type %s.", type));
}
/**
* Locates the given method. Searches all methods, including private methods.
*/
public static <T, R> JavaMethod<T, R> method(Class<T> target, Class<R> returnType, String name, Class<?>... paramTypes) throws NoSuchMethodException {
return new JavaMethod<T, R>(target, returnType, name, paramTypes);
}
/**
* Locates the given static method. Searches all methods, including private methods.
*/
public static <T, R> JavaMethod<T, R> staticMethod(Class<T> target, Class<R> returnType, String name, Class<?>... paramTypes) throws NoSuchMethodException {
return new JavaMethod<T, R>(target, returnType, name, true, paramTypes);
}
/**
* Locates the given method. Searches all methods, including private methods.
*/
public static <T, R> JavaMethod<T, R> method(T target, Class<R> returnType, String name, Class<?>... paramTypes) throws NoSuchMethodException {
@SuppressWarnings("unchecked")
Class<T> targetClass = (Class<T>) target.getClass();
return method(targetClass, returnType, name, paramTypes);
}
/**
* Locates the given method. Searches all methods, including private methods.
*/
public static <T, R> JavaMethod<T, R> method(Class<R> returnType, Method method) throws NoSuchMethodException {
return new JavaMethod<T, R>(returnType, method);
}
public static Method findMethod(Class<?> target, Spec<Method> predicate) {
List<Method> methods = findAllMethodsInternal(target, predicate, new MultiMap<String, Method>(), new ArrayList<Method>(1), true);
return methods.isEmpty() ? null : methods.get(0);
}
public static List<Method> findAllMethods(Class<?> target, Spec<Method> predicate) {
return findAllMethodsInternal(target, predicate, new MultiMap<String, Method>(), new ArrayList<Method>(), false);
}
public static Set<String> propertyNames(Object target) {
Class<?> targetType = target.getClass();
synchronized (PROPERTY_CACHE) {
Set<String> cached = PROPERTY_CACHE.get(targetType);
if (cached == null) {
cached = ClassInspector.inspect(targetType).getPropertyNames();
PROPERTY_CACHE.put(targetType, cached);
}
return cached;
}
}
public static <T> T newInstanceOrFallback(String jdk7Type, ClassLoader loader, Class<? extends T> fallbackType) {
// Use java 7 APIs, if available
Class<?> handlerClass = null;
if (JavaVersion.current().isJava7Compatible()) {
try {
handlerClass = loader.loadClass(jdk7Type);
} catch (ClassNotFoundException e) {
// Ignore
}
}
if (handlerClass == null) {
handlerClass = fallbackType;
}
try {
return Cast.uncheckedCast(handlerClass.newInstance());
} catch (Exception e) {
throw UncheckedException.throwAsUncheckedException(e);
}
}
private static class MultiMap<K, V> extends HashMap<K, List<V>> {
@Override
public List<V> get(Object key) {
if (!containsKey(key)) {
@SuppressWarnings("unchecked") K keyCast = (K) key;
put(keyCast, new LinkedList<V>());
}
return super.get(key);
}
}
private static List<Method> findAllMethodsInternal(Class<?> target, Spec<Method> predicate, MultiMap<String, Method> seen, List<Method> collector, boolean stopAtFirst) {
for (final Method method : target.getDeclaredMethods()) {
List<Method> seenWithName = seen.get(method.getName());
Method override = CollectionUtils.findFirst(seenWithName, new Spec<Method>() {
public boolean isSatisfiedBy(Method potentionOverride) {
return potentionOverride.getName().equals(method.getName())
&& Arrays.equals(potentionOverride.getParameterTypes(), method.getParameterTypes());
}
});
if (override == null) {
seenWithName.add(method);
if (predicate.isSatisfiedBy(method)) {
collector.add(method);
if (stopAtFirst) {
return collector;
}
}
}
}
Class<?> parent = target.getSuperclass();
if (parent != null) {
return findAllMethodsInternal(parent, predicate, seen, collector, stopAtFirst);
}
return collector;
}
public static <A extends Annotation> A getAnnotation(Class<?> type, Class<A> annotationType) {
return getAnnotation(type, annotationType, true);
}
private static <A extends Annotation> A getAnnotation(Class<?> type, Class<A> annotationType, boolean checkType) {
A annotation;
if (checkType) {
annotation = type.getAnnotation(annotationType);
if (annotation != null) {
return annotation;
}
}
if (annotationType.getAnnotation(Inherited.class) != null) {
for (Class<?> anInterface : type.getInterfaces()) {
annotation = getAnnotation(anInterface, annotationType, true);
if (annotation != null) {
return annotation;
}
}
}
if (type.isInterface() || type.equals(Object.class)) {
return null;
} else {
return getAnnotation(type.getSuperclass(), annotationType, false);
}
}
public static <T> Factory<T> factory(final Instantiator instantiator, final Class<? extends T> type, final Object... args) {
return new InstantiatingFactory<T>(instantiator, type, args);
}
public static boolean hasDefaultToString(Object object) {
try {
return object.getClass().getMethod("toString").getDeclaringClass() == Object.class;
} catch (java.lang.NoSuchMethodException e) {
throw new UncheckedException(e);
}
}
private static class GetterMethodBackedPropertyAccessor<T, F> implements PropertyAccessor<T, F> {
private final String property;
private final Method method;
private final Class<F> returnType;
public GetterMethodBackedPropertyAccessor(String property, Class<F> returnType, Method method) {
this.property = property;
this.method = method;
this.returnType = returnType;
}
@Override
public String toString() {
return "property " + method.getDeclaringClass().getSimpleName() + "." + property;
}
public String getName() {
return property;
}
public Class<F> getType() {
return returnType;
}
public F getValue(T target) {
try {
return returnType.cast(method.invoke(target));
} catch (InvocationTargetException e) {
throw UncheckedException.unwrapAndRethrow(e);
} catch (Exception e) {
throw UncheckedException.throwAsUncheckedException(e);
}
}
}
private static class FieldBackedPropertyAccessor<T, F> implements PropertyAccessor<T, F> {
private final String property;
private final Field field;
private final Class<F> fieldType;
public FieldBackedPropertyAccessor(String property, Class<F> fieldType, Field field) {
this.property = property;
this.field = field;
this.fieldType = fieldType;
}
@Override
public String getName() {
return property;
}
@Override
public Class<F> getType() {
return fieldType;
}
@Override
public F getValue(T target) {
try {
return fieldType.cast(field.get(target));
} catch (IllegalAccessException e) {
throw UncheckedException.throwAsUncheckedException(e);
}
}
}
private static class MethodBackedPropertyMutator implements PropertyMutator {
private final String property;
private final Method method;
public MethodBackedPropertyMutator(String property, Method method) {
this.property = property;
this.method = method;
}
@Override
public String toString() {
return "property " + method.getDeclaringClass().getSimpleName() + "." + property;
}
public String getName() {
return property;
}
public Class<?> getType() {
return method.getParameterTypes()[0];
}
public void setValue(Object target, Object value) {
try {
method.invoke(target, value);
} catch (InvocationTargetException e) {
throw UncheckedException.unwrapAndRethrow(e);
} catch (Exception e) {
throw UncheckedException.throwAsUncheckedException(e);
}
}
}
private static class FieldBackedPropertyMutator implements PropertyMutator {
private final String name;
private final Field field;
public FieldBackedPropertyMutator(String name, Field field) {
this.name = name;
this.field = field;
}
@Override
public String toString() {
return "field " + field.getDeclaringClass().getSimpleName() + "." + name;
}
public String getName() {
return name;
}
public Class<?> getType() {
return field.getType();
}
public void setValue(Object target, Object value) {
try {
field.set(target, value);
} catch (IllegalAccessException e) {
throw UncheckedException.throwAsUncheckedException(e);
}
}
}
private static class InstantiatingFactory<T> implements Factory<T> {
private final Instantiator instantiator;
private final Class<? extends T> type;
private final Object[] args;
public InstantiatingFactory(Instantiator instantiator, Class<? extends T> type, Object... args) {
this.instantiator = instantiator;
this.type = type;
this.args = args;
}
public T create() {
return instantiator.newInstance(type, args);
}
}
public static class CachedConstructor extends ReflectionCache.CachedInvokable<Constructor<?>> {
public CachedConstructor(Constructor<?> ctor) {
super(ctor);
}
}
}