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/*
 * 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 freemarker.ext.beans;

import java.beans.BeanInfo;
import java.beans.IndexedPropertyDescriptor;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.MethodDescriptor;
import java.beans.PropertyDescriptor;
import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.IdentityHashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

import freemarker.core.BugException;
import freemarker.core._JavaVersions;
import freemarker.ext.beans.BeansWrapper.MethodAppearanceDecision;
import freemarker.ext.beans.BeansWrapper.MethodAppearanceDecisionInput;
import freemarker.ext.util.ModelCache;
import freemarker.log.Logger;
import freemarker.template.Version;
import freemarker.template.utility.NullArgumentException;
import freemarker.template.utility.SecurityUtilities;

/**
 * Returns information about a {@link Class} that's useful for FreeMarker. Encapsulates a cache for this. Thread-safe,
 * doesn't even require "proper publishing" starting from 2.3.24 or Java 5. Immutable, with the exception of the
 * internal caches.
 * 
 * 

* Note that instances of this are cached on the level of FreeMarker's defining class loader. Hence, it must not do * operations that depend on the Thread Context Class Loader, such as resolving class names. */ class ClassIntrospector { // Attention: This class must be thread-safe (not just after proper publishing). This is important as some of // these are shared by many object wrappers, and concurrency related glitches due to user errors must remain // local to the object wrappers, not corrupting the shared ClassIntrospector. private static final Logger LOG = Logger.getLogger("freemarker.beans"); private static final String JREBEL_SDK_CLASS_NAME = "org.zeroturnaround.javarebel.ClassEventListener"; private static final String JREBEL_INTEGRATION_ERROR_MSG = "Error initializing JRebel integration. JRebel integration disabled."; private static final ExecutableMemberSignature GET_STRING_SIGNATURE = new ExecutableMemberSignature("get", new Class[] { String.class }); private static final ExecutableMemberSignature GET_OBJECT_SIGNATURE = new ExecutableMemberSignature("get", new Class[] { Object.class }); private static final ExecutableMemberSignature TO_STRING_SIGNATURE = new ExecutableMemberSignature("toString", new Class[0]); /** * When this property is true, some things are stricter. This is mostly to catch suspicious things in development * that can otherwise be valid situations. */ static final boolean DEVELOPMENT_MODE = "true".equals(SecurityUtilities.getSystemProperty("freemarker.development", "false")); private static final ClassChangeNotifier CLASS_CHANGE_NOTIFIER; static { boolean jRebelAvailable; try { Class.forName(JREBEL_SDK_CLASS_NAME); jRebelAvailable = true; } catch (Throwable e) { jRebelAvailable = false; try { if (!(e instanceof ClassNotFoundException)) { LOG.error(JREBEL_INTEGRATION_ERROR_MSG, e); } } catch (Throwable loggingE) { // ignore } } ClassChangeNotifier classChangeNotifier; if (jRebelAvailable) { try { classChangeNotifier = (ClassChangeNotifier) Class.forName("freemarker.ext.beans.JRebelClassChangeNotifier").newInstance(); } catch (Throwable e) { classChangeNotifier = null; try { LOG.error(JREBEL_INTEGRATION_ERROR_MSG, e); } catch (Throwable loggingE) { // ignore } } } else { classChangeNotifier = null; } CLASS_CHANGE_NOTIFIER = classChangeNotifier; } // ----------------------------------------------------------------------------------------------------------------- // Introspection info Map keys: /** Key in the class info Map to the Map that maps method to argument type arrays */ private static final Object ARG_TYPES_BY_METHOD_KEY = new Object(); /** Key in the class info Map to the object that represents the constructors (one or multiple due to overloading) */ static final Object CONSTRUCTORS_KEY = new Object(); /** Key in the class info Map to the get(String|Object) Method */ static final Object GENERIC_GET_KEY = new Object(); /** Key in the class info Map to the toString() Method */ static final Object TO_STRING_HIDDEN_FLAG_KEY = new Object(); // ----------------------------------------------------------------------------------------------------------------- // Introspection configuration properties: // Note: These all must be *declared* final (or else synchronization is needed everywhere where they are accessed). final int exposureLevel; final boolean exposeFields; final MemberAccessPolicy memberAccessPolicy; final MethodAppearanceFineTuner methodAppearanceFineTuner; final MethodSorter methodSorter; final boolean treatDefaultMethodsAsBeanMembers; final Version incompatibleImprovements; /** See {@link #getHasSharedInstanceRestrictions()} */ final private boolean hasSharedInstanceRestrictions; /** See {@link #isShared()} */ final private boolean shared; // ----------------------------------------------------------------------------------------------------------------- // State fields: private final Object sharedLock; private final Map, Map> cache = new ConcurrentHashMap<>(0, 0.75f, 16); private final Set cacheClassNames = new HashSet<>(0); private final Set> classIntrospectionsInProgress = new HashSet<>(0); private final List*/>> modelFactories = new LinkedList<>(); private final ReferenceQueue modelFactoriesRefQueue = new ReferenceQueue<>(); private int clearingCounter; // ----------------------------------------------------------------------------------------------------------------- // Instantiation: /** * @param hasSharedInstanceRestrictions * {@code true} exactly if we are creating a new instance with {@link ClassIntrospectorBuilder}. Then * it's {@code true} even if it won't put the instance into the cache. */ ClassIntrospector(ClassIntrospectorBuilder builder, Object sharedLock, boolean hasSharedInstanceRestrictions, boolean shared) { NullArgumentException.check("sharedLock", sharedLock); this.exposureLevel = builder.getExposureLevel(); this.exposeFields = builder.getExposeFields(); this.memberAccessPolicy = builder.getMemberAccessPolicy(); this.methodAppearanceFineTuner = builder.getMethodAppearanceFineTuner(); this.methodSorter = builder.getMethodSorter(); this.treatDefaultMethodsAsBeanMembers = builder.getTreatDefaultMethodsAsBeanMembers(); this.incompatibleImprovements = builder.getIncompatibleImprovements(); this.sharedLock = sharedLock; this.hasSharedInstanceRestrictions = hasSharedInstanceRestrictions; this.shared = shared; if (CLASS_CHANGE_NOTIFIER != null) { CLASS_CHANGE_NOTIFIER.subscribe(this); } } /** * Returns a {@link ClassIntrospectorBuilder} that could be used to create an identical * {@link #ClassIntrospector}. The returned {@link ClassIntrospectorBuilder} can be modified without interfering * with anything. */ ClassIntrospectorBuilder createBuilder() { return new ClassIntrospectorBuilder(this); } // ----------------------------------------------------------------------------------------------------------------- // Introspection: /** * Gets the class introspection data from {@link #cache}, automatically creating the cache entry if it's missing. * * @return A {@link Map} where each key is a property/method/field name (or a special {@link Object} key like * {@link #CONSTRUCTORS_KEY}), each value is a {@link FastPropertyDescriptor} or {@link Method} or * {@link OverloadedMethods} or {@link Field} (but better check the source code...). */ Map get(Class clazz) { { Map introspData = cache.get(clazz); if (introspData != null) return introspData; } String className; synchronized (sharedLock) { Map introspData = cache.get(clazz); if (introspData != null) return introspData; className = clazz.getName(); if (cacheClassNames.contains(className)) { onSameNameClassesDetected(className); } while (introspData == null && classIntrospectionsInProgress.contains(clazz)) { // Another thread is already introspecting this class; // waiting for its result. try { sharedLock.wait(); introspData = cache.get(clazz); } catch (InterruptedException e) { throw new RuntimeException( "Class inrospection data lookup aborded: " + e); } } if (introspData != null) return introspData; // This will be the thread that introspects this class. classIntrospectionsInProgress.add(clazz); } try { Map introspData = createClassIntrospectionData(clazz); synchronized (sharedLock) { cache.put(clazz, introspData); cacheClassNames.add(className); } return introspData; } finally { synchronized (sharedLock) { classIntrospectionsInProgress.remove(clazz); sharedLock.notifyAll(); } } } /** * Creates a {@link Map} with the content as described for the return value of {@link #get(Class)}. */ private Map createClassIntrospectionData(Class clazz) { final Map introspData = new HashMap<>(); MemberAccessPolicy effMemberAccessPolicy = getEffectiveMemberAccessPolicy(); ClassMemberAccessPolicy effClassMemberAccessPolicy = effMemberAccessPolicy.forClass(clazz); if (exposeFields) { addFieldsToClassIntrospectionData(introspData, clazz, effClassMemberAccessPolicy); } final Map> accessibleMethods = discoverAccessibleMethods(clazz); if (!effMemberAccessPolicy.isToStringAlwaysExposed()) { addToStringHiddenFlagToClassIntrospectionData(introspData, accessibleMethods, effClassMemberAccessPolicy); } addGenericGetToClassIntrospectionData(introspData, accessibleMethods, effClassMemberAccessPolicy); if (exposureLevel != BeansWrapper.EXPOSE_NOTHING) { try { addBeanInfoToClassIntrospectionData(introspData, clazz, accessibleMethods, effClassMemberAccessPolicy); } catch (IntrospectionException e) { LOG.warn("Couldn't properly perform introspection for class " + clazz, e); introspData.clear(); // FIXME NBC: Don't drop everything here. } } addConstructorsToClassIntrospectionData(introspData, clazz, effClassMemberAccessPolicy); if (introspData.size() > 1) { return introspData; } else if (introspData.size() == 0) { return Collections.emptyMap(); } else { // map.size() == 1 Entry e = introspData.entrySet().iterator().next(); return Collections.singletonMap(e.getKey(), e.getValue()); } } private void addFieldsToClassIntrospectionData(Map introspData, Class clazz, ClassMemberAccessPolicy effClassMemberAccessPolicy) throws SecurityException { Field[] fields = clazz.getFields(); for (int i = 0; i < fields.length; i++) { Field field = fields[i]; if ((field.getModifiers() & Modifier.STATIC) == 0) { if (effClassMemberAccessPolicy.isFieldExposed(field)) { introspData.put(field.getName(), field); } } } } private void addBeanInfoToClassIntrospectionData( Map introspData, Class clazz, Map> accessibleMethods, ClassMemberAccessPolicy effClassMemberAccessPolicy) throws IntrospectionException { BeanInfo beanInfo = Introspector.getBeanInfo(clazz); List pdas = getPropertyDescriptors(beanInfo, clazz); int pdasLength = pdas.size(); // Reverse order shouldn't mater, but we keep it to not risk backward incompatibility. for (int i = pdasLength - 1; i >= 0; --i) { addPropertyDescriptorToClassIntrospectionData( introspData, pdas.get(i), accessibleMethods, effClassMemberAccessPolicy); } if (exposureLevel < BeansWrapper.EXPOSE_PROPERTIES_ONLY) { final MethodAppearanceDecision decision = new MethodAppearanceDecision(); MethodAppearanceDecisionInput decisionInput = null; List mds = getMethodDescriptors(beanInfo, clazz); sortMethodDescriptors(mds); int mdsSize = mds.size(); IdentityHashMap argTypesUsedByIndexerPropReaders = null; for (int i = mdsSize - 1; i >= 0; --i) { final Method method = getMatchingAccessibleMethod(mds.get(i).getMethod(), accessibleMethods); if (method != null && effClassMemberAccessPolicy.isMethodExposed(method)) { decision.setDefaults(method); if (methodAppearanceFineTuner != null) { if (decisionInput == null) { decisionInput = new MethodAppearanceDecisionInput(); } decisionInput.setContainingClass(clazz); decisionInput.setMethod(method); methodAppearanceFineTuner.process(decisionInput, decision); } PropertyDescriptor propDesc = decision.getExposeAsProperty(); if (propDesc != null && (decision.getReplaceExistingProperty() || !(introspData.get(propDesc.getName()) instanceof FastPropertyDescriptor))) { addPropertyDescriptorToClassIntrospectionData( introspData, propDesc, accessibleMethods, effClassMemberAccessPolicy); } String methodKey = decision.getExposeMethodAs(); if (methodKey != null) { Object previous = introspData.get(methodKey); if (previous instanceof Method) { // Overloaded method - replace Method with a OverloadedMethods OverloadedMethods overloadedMethods = new OverloadedMethods(is2321Bugfixed()); overloadedMethods.addMethod((Method) previous); overloadedMethods.addMethod(method); introspData.put(methodKey, overloadedMethods); // Remove parameter type information (unless an indexed property reader needs it): if (argTypesUsedByIndexerPropReaders == null || !argTypesUsedByIndexerPropReaders.containsKey(previous)) { getArgTypesByMethod(introspData).remove(previous); } } else if (previous instanceof OverloadedMethods) { // Already overloaded method - add new overload ((OverloadedMethods) previous).addMethod(method); } else if (decision.getMethodShadowsProperty() || !(previous instanceof FastPropertyDescriptor)) { // Simple method (this far) introspData.put(methodKey, method); Class[] replaced = getArgTypesByMethod(introspData).put(method, method.getParameterTypes()); if (replaced != null) { if (argTypesUsedByIndexerPropReaders == null) { argTypesUsedByIndexerPropReaders = new IdentityHashMap<>(); } argTypesUsedByIndexerPropReaders.put(method, null); } } } } } // for each in mds } // end if (exposureLevel < EXPOSE_PROPERTIES_ONLY) } /** * Very similar to {@link BeanInfo#getPropertyDescriptors()}, but can deal with Java 8 default methods too. */ private List getPropertyDescriptors(BeanInfo beanInfo, Class clazz) { PropertyDescriptor[] introspectorPDsArray = beanInfo.getPropertyDescriptors(); List introspectorPDs = introspectorPDsArray != null ? Arrays.asList(introspectorPDsArray) : Collections.emptyList(); if (!treatDefaultMethodsAsBeanMembers || _JavaVersions.JAVA_8 == null) { // java.beans.Introspector was good enough then. return introspectorPDs; } // introspectorPDs contains each property exactly once. But as now we will search them manually too, it can // happen that we find the same property for multiple times. Worse, because of indexed properties, it's possible // that we have to merge entries (like one has the normal reader method, the other has the indexed reader // method), instead of just replacing them in a Map. That's why we have introduced PropertyReaderMethodPair, // which holds the methods belonging to the same property name. IndexedPropertyDescriptor is not good for that, // as it can't store two methods whose types are incompatible, and we have to wait until all the merging was // done to see if the incompatibility goes away. // This could be Map, but since we rarely need to do merging, we try to avoid // creating those and use the source objects as much as possible. Also note that we initialize this lazily. LinkedHashMap mergedPRMPs = null; // Collect Java 8 default methods that look like property readers into mergedPRMPs: // (Note that java.beans.Introspector discovers non-accessible public methods, and to emulate that behavior // here, we don't utilize the accessibleMethods Map, which we might already have at this point.) for (Method method : clazz.getMethods()) { if (_JavaVersions.JAVA_8.isDefaultMethod(method) && method.getReturnType() != void.class && !method.isBridge()) { Class[] paramTypes = method.getParameterTypes(); if (paramTypes.length == 0 || paramTypes.length == 1 && paramTypes[0] == int.class /* indexed property reader */) { String propName = _MethodUtil.getBeanPropertyNameFromReaderMethodName( method.getName(), method.getReturnType()); if (propName != null) { if (mergedPRMPs == null) { // Lazy initialization mergedPRMPs = new LinkedHashMap<>(); } if (paramTypes.length == 0) { mergeInPropertyReaderMethod(mergedPRMPs, propName, method); } else { // It's an indexed property reader method mergeInPropertyReaderMethodPair(mergedPRMPs, propName, new PropertyReaderMethodPair(null, method)); } } } } } // for clazz.getMethods() if (mergedPRMPs == null) { // We had no interfering Java 8 default methods, so we can chose the fast route. return introspectorPDs; } for (PropertyDescriptor introspectorPD : introspectorPDs) { mergeInPropertyDescriptor(mergedPRMPs, introspectorPD); } // Now we convert the PRMPs to PDs, handling case where the normal and the indexed read methods contradict. List mergedPDs = new ArrayList<>(mergedPRMPs.size()); for (Entry entry : mergedPRMPs.entrySet()) { String propName = entry.getKey(); Object propDescObj = entry.getValue(); if (propDescObj instanceof PropertyDescriptor) { mergedPDs.add((PropertyDescriptor) propDescObj); } else { Method readMethod; Method indexedReadMethod; if (propDescObj instanceof Method) { readMethod = (Method) propDescObj; indexedReadMethod = null; } else if (propDescObj instanceof PropertyReaderMethodPair) { PropertyReaderMethodPair prmp = (PropertyReaderMethodPair) propDescObj; readMethod = prmp.readMethod; indexedReadMethod = prmp.indexedReadMethod; if (readMethod != null && indexedReadMethod != null && indexedReadMethod.getReturnType() != readMethod.getReturnType().getComponentType()) { // Here we copy the java.beans.Introspector behavior: If the array item class is not exactly the // the same as the indexed read method return type, we say that the property is not indexed. indexedReadMethod = null; } } else { throw new BugException(); } try { mergedPDs.add( indexedReadMethod != null ? new IndexedPropertyDescriptor(propName, readMethod, null, indexedReadMethod, null) : new PropertyDescriptor(propName, readMethod, null)); } catch (IntrospectionException e) { if (LOG.isWarnEnabled()) { LOG.warn("Failed creating property descriptor for " + clazz.getName() + " property " + propName, e); } } } } return mergedPDs; } private static class PropertyReaderMethodPair { private final Method readMethod; private final Method indexedReadMethod; PropertyReaderMethodPair(Method readerMethod, Method indexedReaderMethod) { this.readMethod = readerMethod; this.indexedReadMethod = indexedReaderMethod; } PropertyReaderMethodPair(PropertyDescriptor pd) { this( pd.getReadMethod(), pd instanceof IndexedPropertyDescriptor ? ((IndexedPropertyDescriptor) pd).getIndexedReadMethod() : null); } static PropertyReaderMethodPair from(Object obj) { if (obj instanceof PropertyReaderMethodPair) { return (PropertyReaderMethodPair) obj; } else if (obj instanceof PropertyDescriptor) { return new PropertyReaderMethodPair((PropertyDescriptor) obj); } else if (obj instanceof Method) { return new PropertyReaderMethodPair((Method) obj, null); } else { throw new BugException("Unexpected obj type: " + obj.getClass().getName()); } } static PropertyReaderMethodPair merge(PropertyReaderMethodPair oldMethods, PropertyReaderMethodPair newMethods) { return new PropertyReaderMethodPair( newMethods.readMethod != null ? newMethods.readMethod : oldMethods.readMethod, newMethods.indexedReadMethod != null ? newMethods.indexedReadMethod : oldMethods.indexedReadMethod); } @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + ((indexedReadMethod == null) ? 0 : indexedReadMethod.hashCode()); result = prime * result + ((readMethod == null) ? 0 : readMethod.hashCode()); return result; } @Override public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; PropertyReaderMethodPair other = (PropertyReaderMethodPair) obj; return other.readMethod == readMethod && other.indexedReadMethod == indexedReadMethod; } } private void mergeInPropertyDescriptor(LinkedHashMap mergedPRMPs, PropertyDescriptor pd) { String propName = pd.getName(); Object replaced = mergedPRMPs.put(propName, pd); if (replaced != null) { PropertyReaderMethodPair newPRMP = new PropertyReaderMethodPair(pd); putIfMergedPropertyReaderMethodPairDiffers(mergedPRMPs, propName, replaced, newPRMP); } } private void mergeInPropertyReaderMethodPair(LinkedHashMap mergedPRMPs, String propName, PropertyReaderMethodPair newPRM) { Object replaced = mergedPRMPs.put(propName, newPRM); if (replaced != null) { putIfMergedPropertyReaderMethodPairDiffers(mergedPRMPs, propName, replaced, newPRM); } } private void mergeInPropertyReaderMethod(LinkedHashMap mergedPRMPs, String propName, Method readerMethod) { Object replaced = mergedPRMPs.put(propName, readerMethod); if (replaced != null) { putIfMergedPropertyReaderMethodPairDiffers(mergedPRMPs, propName, replaced, new PropertyReaderMethodPair(readerMethod, null)); } } private void putIfMergedPropertyReaderMethodPairDiffers(LinkedHashMap mergedPRMPs, String propName, Object replaced, PropertyReaderMethodPair newPRMP) { PropertyReaderMethodPair replacedPRMP = PropertyReaderMethodPair.from(replaced); PropertyReaderMethodPair mergedPRMP = PropertyReaderMethodPair.merge(replacedPRMP, newPRMP); if (!mergedPRMP.equals(newPRMP)) { mergedPRMPs.put(propName, mergedPRMP); } } /** * Very similar to {@link BeanInfo#getMethodDescriptors()}, but can deal with Java 8 default methods too. */ private List getMethodDescriptors(BeanInfo beanInfo, Class clazz) { MethodDescriptor[] introspectorMDArray = beanInfo.getMethodDescriptors(); List introspectionMDs = introspectorMDArray != null && introspectorMDArray.length != 0 ? Arrays.asList(introspectorMDArray) : Collections.emptyList(); if (!treatDefaultMethodsAsBeanMembers || _JavaVersions.JAVA_8 == null) { // java.beans.Introspector was good enough then. return introspectionMDs; } Map> defaultMethodsToAddByName = null; for (Method method : clazz.getMethods()) { if (_JavaVersions.JAVA_8.isDefaultMethod(method) && !method.isBridge()) { if (defaultMethodsToAddByName == null) { defaultMethodsToAddByName = new HashMap<>(); } List overloads = defaultMethodsToAddByName.get(method.getName()); if (overloads == null) { overloads = new ArrayList<>(0); defaultMethodsToAddByName.put(method.getName(), overloads); } overloads.add(method); } } if (defaultMethodsToAddByName == null) { // We had no interfering default methods: return introspectionMDs; } // Recreate introspectionMDs so that its size can grow: ArrayList newIntrospectionMDs = new ArrayList<>(introspectionMDs.size() + 16); for (MethodDescriptor introspectorMD : introspectionMDs) { Method introspectorM = introspectorMD.getMethod(); // Prevent cases where the same method is added with different return types both from the list of default // methods and from the list of Introspector-discovered methods, as that would lead to overloaded method // selection ambiguity later. This is known to happen when the default method in an interface has reified // return type, and then the interface is implemented by a class where the compiler generates an override // for the bridge method only. (Other tricky cases might exist.) if (!containsMethodWithSameParameterTypes( defaultMethodsToAddByName.get(introspectorM.getName()), introspectorM)) { newIntrospectionMDs.add(introspectorMD); } } introspectionMDs = newIntrospectionMDs; // Add default methods: for (Entry> entry : defaultMethodsToAddByName.entrySet()) { for (Method method : entry.getValue()) { introspectionMDs.add(new MethodDescriptor(method)); } } return introspectionMDs; } private boolean containsMethodWithSameParameterTypes(List overloads, Method m) { if (overloads == null) { return false; } Class[] paramTypes = m.getParameterTypes(); for (Method overload : overloads) { if (Arrays.equals(overload.getParameterTypes(), paramTypes)) { return true; } } return false; } private void addPropertyDescriptorToClassIntrospectionData(Map introspData, PropertyDescriptor pd, Map> accessibleMethods, ClassMemberAccessPolicy effClassMemberAccessPolicy) { Method readMethod = getMatchingAccessibleMethod(pd.getReadMethod(), accessibleMethods); if (readMethod != null && !effClassMemberAccessPolicy.isMethodExposed(readMethod)) { readMethod = null; } Method indexedReadMethod; if (pd instanceof IndexedPropertyDescriptor) { indexedReadMethod = getMatchingAccessibleMethod( ((IndexedPropertyDescriptor) pd).getIndexedReadMethod(), accessibleMethods); if (indexedReadMethod != null && !effClassMemberAccessPolicy.isMethodExposed(indexedReadMethod)) { indexedReadMethod = null; } if (indexedReadMethod != null) { getArgTypesByMethod(introspData).put( indexedReadMethod, indexedReadMethod.getParameterTypes()); } } else { indexedReadMethod = null; } if (readMethod != null || indexedReadMethod != null) { introspData.put(pd.getName(), new FastPropertyDescriptor(readMethod, indexedReadMethod)); } } private void addGenericGetToClassIntrospectionData(Map introspData, Map> accessibleMethods, ClassMemberAccessPolicy effClassMemberAccessPolicy) { Method genericGet = getFirstAccessibleMethod(GET_STRING_SIGNATURE, accessibleMethods); if (genericGet == null) { genericGet = getFirstAccessibleMethod(GET_OBJECT_SIGNATURE, accessibleMethods); } if (genericGet != null && effClassMemberAccessPolicy.isMethodExposed(genericGet)) { introspData.put(GENERIC_GET_KEY, genericGet); } } private void addToStringHiddenFlagToClassIntrospectionData(Map introspData, Map> accessibleMethods, ClassMemberAccessPolicy effClassMemberAccessPolicy) { Method toStringMethod = getFirstAccessibleMethod(TO_STRING_SIGNATURE, accessibleMethods); if (toStringMethod == null) { throw new BugException("toString() method not found"); } // toString() is pretty much always exposed, so we make the negative case to take extra memory: if (!effClassMemberAccessPolicy.isMethodExposed(toStringMethod)) { introspData.put(TO_STRING_HIDDEN_FLAG_KEY, true); } } private void addConstructorsToClassIntrospectionData(final Map introspData, Class clazz, ClassMemberAccessPolicy effClassMemberAccessPolicy) { try { Constructor[] ctorsUnfiltered = clazz.getConstructors(); List> ctors = new ArrayList<>(ctorsUnfiltered.length); for (Constructor ctor : ctorsUnfiltered) { if (effClassMemberAccessPolicy.isConstructorExposed(ctor)) { ctors.add(ctor); } } if (!ctors.isEmpty()) { final Object ctorsIntrospData; if (ctors.size() == 1) { Constructor ctor = ctors.get(0); ctorsIntrospData = new SimpleMethod(ctor, ctor.getParameterTypes()); } else { OverloadedMethods overloadedCtors = new OverloadedMethods(is2321Bugfixed()); for (Constructor ctor : ctors) { overloadedCtors.addConstructor(ctor); } ctorsIntrospData = overloadedCtors; } introspData.put(CONSTRUCTORS_KEY, ctorsIntrospData); } } catch (SecurityException e) { LOG.warn("Can't discover constructors for class " + clazz.getName(), e); } } /** * Retrieves mapping of {@link ExecutableMemberSignature}-s to a {@link List} of accessible methods for a class. In * case the class is not public, retrieves methods with same signature as its public methods from public * superclasses and interfaces. Basically upcasts every method to the nearest accessible method. */ private static Map> discoverAccessibleMethods(Class clazz) { Map> accessibles = new HashMap<>(); discoverAccessibleMethods(clazz, accessibles); return accessibles; } private static void discoverAccessibleMethods( Class clazz, Map> accessibles) { if (Modifier.isPublic(clazz.getModifiers())) { try { Method[] methods = clazz.getMethods(); for (int i = 0; i < methods.length; i++) { Method method = methods[i]; if (Modifier.isPublic(method.getDeclaringClass().getModifiers())) { ExecutableMemberSignature sig = new ExecutableMemberSignature(method); // Contrary to intuition, a class can actually have several // different methods with same signature *but* different // return types. These can't be constructed using Java the // language, as this is illegal on source code level, but // the compiler can emit synthetic methods as part of // generic type reification that will have same signature // yet different return type than an existing explicitly // declared method. Consider: // public interface I { T m(); } // public class C implements I { Integer m() { return 42; } } // C.class will have both "Object m()" and "Integer m()" methods. List methodList = accessibles.get(sig); if (methodList == null) { // TODO Collection.singletonList is more efficient, though read only. methodList = new LinkedList<>(); accessibles.put(sig, methodList); } methodList.add(method); } } return; } catch (SecurityException e) { LOG.warn("Could not discover accessible methods of class " + clazz.getName() + ", attemping superclasses/interfaces.", e); // Fall through and attempt to discover superclass/interface methods } } Class[] interfaces = clazz.getInterfaces(); for (int i = 0; i < interfaces.length; i++) { discoverAccessibleMethods(interfaces[i], accessibles); } Class superclass = clazz.getSuperclass(); if (superclass != null) { discoverAccessibleMethods(superclass, accessibles); } } // This is needed as java.bean.Introspector sometimes gives back a method that's actually not accessible, // as it's an override of an accessible method in a non-public subclass. While that's still a public method, calling // it directly via reflection will throw java.lang.IllegalAccessException, and we are supposed to call the overidden // accessible method instead. Like, we might get two PropertyDescriptor-s for the same property name, and only one // will have a reader method that we can actually call. So we have to find that method here. // Furthermore, the return type of the inaccessible method is possibly different (more specific) than the return // type of the overridden accessible method. Also Introspector behavior changed with Java 9, as earlier in such // case the Introspector returned all variants of the method (so the accessible one was amongst them at least), // while in Java 9 it apparently always returns one variant only, but that's sometimes (not sure if it's // predictable) the inaccessible one. private static Method getMatchingAccessibleMethod(Method m, Map> accessibles) { if (m == null) { return null; } List ams = accessibles.get(new ExecutableMemberSignature(m)); // Certainly we could return any of the accessibles, as Java reflection will call the correct override of the // method anyway. There's an ambiguity when the return type is "overloaded", but in practice it probably doesn't // matter which variant we call. Though, technically, they could do totally different things. So, to avoid any // corner cases that cause problems after an upgrade, we make an effort to give same result as before 2.3.31. return ams != null ? _MethodUtil.getMethodWithClosestNonSubReturnType(m.getReturnType(), ams) : null; } private static Method getFirstAccessibleMethod( ExecutableMemberSignature sig, Map> accessibles) { List ams = accessibles.get(sig); if (ams == null || ams.isEmpty()) { return null; } return ams.get(0); } /** * As of this writing, this is only used for testing if method order really doesn't mater. */ private void sortMethodDescriptors(List methodDescriptors) { if (methodSorter != null) { methodSorter.sortMethodDescriptors(methodDescriptors); } } /** * Returns the {@link MemberAccessPolicy} to actually use, which is not just * {@link BeansWrapper#getMemberAccessPolicy()} if {@link BeansWrapper#getExposureLevel()} is more * allowing than {@link BeansWrapper#EXPOSE_SAFE}. {@link BeansWrapper#EXPOSE_NOTHING} though is * not factored in here. */ MemberAccessPolicy getEffectiveMemberAccessPolicy() { return exposureLevel < BeansWrapper.EXPOSE_SAFE ? AllowAllMemberAccessPolicy.INSTANCE : memberAccessPolicy; } private boolean is2321Bugfixed() { return BeansWrapper.is2321Bugfixed(incompatibleImprovements); } private static Map[]> getArgTypesByMethod(Map classInfo) { @SuppressWarnings("unchecked") Map[]> argTypes = (Map[]>) classInfo.get(ARG_TYPES_BY_METHOD_KEY); if (argTypes == null) { argTypes = new HashMap<>(); classInfo.put(ARG_TYPES_BY_METHOD_KEY, argTypes); } return argTypes; } // ----------------------------------------------------------------------------------------------------------------- // Cache management: /** * Corresponds to {@link BeansWrapper#clearClassIntrospectionCache()}. * * @since 2.3.20 */ void clearCache() { if (getHasSharedInstanceRestrictions()) { throw new IllegalStateException( "It's not allowed to clear the whole cache in a read-only " + this.getClass().getName() + "instance. Use removeFromClassIntrospectionCache(String prefix) instead."); } forcedClearCache(); } private void forcedClearCache() { synchronized (sharedLock) { cache.clear(); cacheClassNames.clear(); clearingCounter++; for (WeakReference regedMfREf : modelFactories) { Object regedMf = regedMfREf.get(); if (regedMf != null) { if (regedMf instanceof ClassBasedModelFactory) { ((ClassBasedModelFactory) regedMf).clearCache(); } else if (regedMf instanceof ModelCache) { ((ModelCache) regedMf).clearCache(); } else { throw new BugException(); } } } removeClearedModelFactoryReferences(); } } /** * Corresponds to {@link BeansWrapper#removeFromClassIntrospectionCache(Class)}. * * @since 2.3.20 */ void remove(Class clazz) { synchronized (sharedLock) { cache.remove(clazz); cacheClassNames.remove(clazz.getName()); clearingCounter++; for (WeakReference regedMfREf : modelFactories) { Object regedMf = regedMfREf.get(); if (regedMf != null) { if (regedMf instanceof ClassBasedModelFactory) { ((ClassBasedModelFactory) regedMf).removeFromCache(clazz); } else if (regedMf instanceof ModelCache) { ((ModelCache) regedMf).clearCache(); // doesn't support selective clearing ATM } else { throw new BugException(); } } } removeClearedModelFactoryReferences(); } } /** * Returns the number of events so far that could make class introspection data returned earlier outdated. */ int getClearingCounter() { synchronized (sharedLock) { return clearingCounter; } } private void onSameNameClassesDetected(String className) { // TODO: This behavior should be pluggable, as in environments where // some classes are often reloaded or multiple versions of the // same class is normal (OSGi), this will drop the cache contents // too often. if (LOG.isInfoEnabled()) { LOG.info( "Detected multiple classes with the same name, \"" + className + "\". Assuming it was a class-reloading. Clearing class introspection " + "caches to release old data."); } forcedClearCache(); } // ----------------------------------------------------------------------------------------------------------------- // Managing dependent objects: void registerModelFactory(ClassBasedModelFactory mf) { registerModelFactory((Object) mf); } void registerModelFactory(ModelCache mf) { registerModelFactory((Object) mf); } private void registerModelFactory(Object mf) { // Note that this `synchronized (sharedLock)` is also need for the BeansWrapper constructor to work safely. synchronized (sharedLock) { modelFactories.add(new WeakReference<>(mf, modelFactoriesRefQueue)); removeClearedModelFactoryReferences(); } } void unregisterModelFactory(ClassBasedModelFactory mf) { unregisterModelFactory((Object) mf); } void unregisterModelFactory(ModelCache mf) { unregisterModelFactory((Object) mf); } void unregisterModelFactory(Object mf) { synchronized (sharedLock) { for (Iterator> it = modelFactories.iterator(); it.hasNext(); ) { Object regedMf = it.next().get(); if (regedMf == mf) { it.remove(); } } } } private void removeClearedModelFactoryReferences() { Reference cleardRef; while ((cleardRef = modelFactoriesRefQueue.poll()) != null) { synchronized (sharedLock) { findClearedRef: for (Iterator> it = modelFactories.iterator(); it.hasNext(); ) { if (it.next() == cleardRef) { it.remove(); break findClearedRef; } } } } } // ----------------------------------------------------------------------------------------------------------------- // Extracting from introspection info: static Class[] getArgTypes(Map classInfo, Method method) { @SuppressWarnings("unchecked") Map[]> argTypesByMethod = (Map[]>) classInfo.get(ARG_TYPES_BY_METHOD_KEY); return argTypesByMethod.get(method); } /** * Returns the number of introspected methods/properties that should be available via the TemplateHashModel * interface. */ int keyCount(Class clazz) { Map map = get(clazz); int count = map.size(); if (map.containsKey(CONSTRUCTORS_KEY)) count--; if (map.containsKey(GENERIC_GET_KEY)) count--; if (map.containsKey(ARG_TYPES_BY_METHOD_KEY)) count--; return count; } /** * Returns the Set of names of introspected methods/properties that should be available via the TemplateHashModel * interface. */ Set keySet(Class clazz) { Set set = new HashSet<>(get(clazz).keySet()); set.remove(CONSTRUCTORS_KEY); set.remove(GENERIC_GET_KEY); set.remove(ARG_TYPES_BY_METHOD_KEY); return set; } // ----------------------------------------------------------------------------------------------------------------- // Properties int getExposureLevel() { return exposureLevel; } boolean getExposeFields() { return exposeFields; } MemberAccessPolicy getMemberAccessPolicy() { return memberAccessPolicy; } boolean getTreatDefaultMethodsAsBeanMembers() { return treatDefaultMethodsAsBeanMembers; } MethodAppearanceFineTuner getMethodAppearanceFineTuner() { return methodAppearanceFineTuner; } MethodSorter getMethodSorter() { return methodSorter; } /** * Returns {@code true} if this instance was created with {@link ClassIntrospectorBuilder}, even if it wasn't * actually put into the cache (as we reserve the right to do so in later versions). */ boolean getHasSharedInstanceRestrictions() { return hasSharedInstanceRestrictions; } /** * Tells if this instance is (potentially) shared among {@link BeansWrapper} instances. * * @see #getHasSharedInstanceRestrictions() */ boolean isShared() { return shared; } /** * Almost always, you want to use {@link BeansWrapper#getSharedIntrospectionLock()}, not this! The only exception is * when you get this to set the field returned by {@link BeansWrapper#getSharedIntrospectionLock()}. */ Object getSharedLock() { return sharedLock; } // ----------------------------------------------------------------------------------------------------------------- // Monitoring: /** For unit testing only */ Object[] getRegisteredModelFactoriesSnapshot() { synchronized (sharedLock) { return modelFactories.toArray(); } } }