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/*
 * JBoss, Home of Professional Open Source
 * Copyright 2008, Red Hat, Inc. and/or its affiliates, and individual contributors
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * 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.jboss.weld.bean.proxy;

import static org.jboss.classfilewriter.util.DescriptorUtils.isPrimitive;
import static org.jboss.classfilewriter.util.DescriptorUtils.isWide;
import static org.jboss.weld.util.reflection.Reflections.cast;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.Serializable;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.Type;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.ProtectionDomain;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;

import javax.enterprise.inject.spi.Bean;

import org.jboss.classfilewriter.AccessFlag;
import org.jboss.classfilewriter.ClassFile;
import org.jboss.classfilewriter.ClassMethod;
import org.jboss.classfilewriter.DuplicateMemberException;
import org.jboss.classfilewriter.code.BranchEnd;
import org.jboss.classfilewriter.code.CodeAttribute;
import org.jboss.classfilewriter.util.Boxing;
import org.jboss.classfilewriter.util.DescriptorUtils;
import org.jboss.weld.Container;
import org.jboss.weld.bean.builtin.AbstractBuiltInBean;
import org.jboss.weld.config.WeldConfiguration;
import org.jboss.weld.exceptions.DefinitionException;
import org.jboss.weld.exceptions.WeldException;
import org.jboss.weld.interceptor.proxy.LifecycleMixin;
import org.jboss.weld.interceptor.util.proxy.TargetInstanceProxy;
import org.jboss.weld.logging.BeanLogger;
import org.jboss.weld.security.GetDeclaredConstructorsAction;
import org.jboss.weld.security.GetDeclaredMethodsAction;
import org.jboss.weld.security.GetProtectionDomainAction;
import org.jboss.weld.serialization.spi.BeanIdentifier;
import org.jboss.weld.serialization.spi.ContextualStore;
import org.jboss.weld.serialization.spi.ProxyServices;
import org.jboss.weld.util.Proxies;
import org.jboss.weld.util.Proxies.TypeInfo;
import org.jboss.weld.util.bytecode.BytecodeUtils;
import org.jboss.weld.util.bytecode.ClassFileUtils;
import org.jboss.weld.util.bytecode.ConstructorUtils;
import org.jboss.weld.util.bytecode.DeferredBytecode;
import org.jboss.weld.util.bytecode.MethodInformation;
import org.jboss.weld.util.bytecode.RuntimeMethodInformation;
import org.jboss.weld.util.collections.Arrays2;
import org.jboss.weld.util.collections.ImmutableSet;
import org.jboss.weld.util.collections.Sets;
import org.jboss.weld.util.reflection.Reflections;


/**
 * Main factory to produce proxy classes and instances for Weld beans. This
 * implementation creates proxies which forward non-static method invocations to
 * a {@link BeanInstance}. All proxies implement the {@link Proxy} interface.
 *
 * @author David Allen
 * @author Stuart Douglas
 * @author Marius Bogoevici
 * @author Ales Justin
 */
public class ProxyFactory implements PrivilegedAction {

    // Default proxy class name suffix
    public static final String PROXY_SUFFIX = "$Proxy$";
    public static final String DEFAULT_PROXY_PACKAGE = "org.jboss.weld.proxies";

    private final Class beanType;
    private final Set> additionalInterfaces = new LinkedHashSet>();
    private final ClassLoader classLoader;
    private final String baseProxyName;
    private final Bean bean;
    private final Class proxiedBeanType;
    private final String contextId;

    private final WeldConfiguration configuration;

    public static final String CONSTRUCTED_FLAG_NAME = "constructed";

    private final ProxyInstantiator proxyInstantiator;

    protected static final BytecodeMethodResolver DEFAULT_METHOD_RESOLVER = new DefaultBytecodeMethodResolver();

    protected static final String LJAVA_LANG_REFLECT_METHOD = "Ljava/lang/reflect/Method;";
    protected static final String LJAVA_LANG_BYTE = "Ljava/lang/Byte;";
    protected static final String LJAVA_LANG_CLASS = "Ljava/lang/Class;";
    protected static final String LJAVA_LANG_OBJECT = "Ljava/lang/Object;";
    protected static final String LBEAN_IDENTIFIER = "Lorg/jboss/weld/serialization/spi/BeanIdentifier;";
    protected static final String LJAVA_LANG_STRING = "Ljava/lang/String;";
    protected static final String LJAVA_LANG_THREAD_LOCAL = "Ljava/lang/ThreadLocal;";

    protected static final String INIT_METHOD_NAME = "";
    protected static final String METHOD_HANDLER_FIELD_NAME = "methodHandler";
    static final String JAVA = "java";

    private static final Set METHOD_FILTERS;

    // class access flags are configurable since classfilewriter 1.1.2.Final
    // with older versions we silently fall back to default access flags (no SYNTHETIC support)
    private static final boolean CONFIGURABLE_ACCESS_FLAGS;

    // classloader is configurable since classfilewriter 1.2.0.Beta1
    // with older versions we silently fall back - no default method interception support
    private static final Constructor CONFIGURABLE_CLASSLOADER_CONSTRUCTOR;

    static {
        Constructor temp = null;
        try {
            temp = SecurityActions.getConstructor(ClassFile.class, String.class, int.class, String.class, ClassLoader.class, Arrays2.EMPTY_STRING_ARRAY.getClass());
        } catch (NoSuchMethodException ignored) {
        }
        if (temp != null) {
            CONFIGURABLE_CLASSLOADER_CONSTRUCTOR = temp;
            CONFIGURABLE_ACCESS_FLAGS = true;
        } else {
            try {
                temp = SecurityActions.getConstructor(ClassFile.class, String.class, int.class, String.class, Arrays2.EMPTY_STRING_ARRAY.getClass());
            } catch (NoSuchMethodException ignored) {
            }
            CONFIGURABLE_CLASSLOADER_CONSTRUCTOR = null;
            CONFIGURABLE_ACCESS_FLAGS = temp != null;
        }
    }

    static {
        Set filters = new HashSet<>();
        filters.add(CommonProxiedMethodFilters.NON_STATIC);
        filters.add(CommonProxiedMethodFilters.NON_FINAL);
        filters.add(CommonProxiedMethodFilters.OBJECT_TO_STRING);
        filters.add(CommonProxiedMethodFilters.NON_JDK_PACKAGE_PRIVATE);
        GroovyMethodFilter groovy = new GroovyMethodFilter();
        if (groovy.isEnabled()) {
            filters.add(groovy);
        }
        METHOD_FILTERS = ImmutableSet.copyOf(filters);
    }

    /**
     * created a new proxy factory from a bean instance. The proxy name is
     * generated from the bean id
     */
    public ProxyFactory(String contextId, Class proxiedBeanType, Set typeClosure, Bean bean) {
        this(contextId, proxiedBeanType, typeClosure, bean, false);
    }

    public ProxyFactory(String contextId, Class proxiedBeanType, Set typeClosure, Bean bean, boolean forceSuperClass) {
        this(contextId, proxiedBeanType, typeClosure, getProxyName(contextId, proxiedBeanType, typeClosure, bean), bean, forceSuperClass);
    }

    /**
     * Creates a new proxy factory when the name of the proxy class is already
     * known, such as during de-serialization
     *
     * @param proxiedBeanType the super-class for this proxy class
     * @param typeClosure     the bean types of the bean
     * @param proxyName       the name of the proxy class
     */
    public ProxyFactory(String contextId, Class proxiedBeanType, Set typeClosure, String proxyName, Bean bean) {
        this(contextId, proxiedBeanType, typeClosure, proxyName, bean, false);
    }

    public ProxyFactory(String contextId, Class proxiedBeanType, Set typeClosure, String proxyName, Bean bean, boolean forceSuperClass) {
        this.bean = bean;
        this.contextId = contextId;
        this.proxiedBeanType = proxiedBeanType;
        this.configuration = Container.instance(contextId).deploymentManager().getServices().get(WeldConfiguration.class);
        addInterfacesFromTypeClosure(typeClosure, proxiedBeanType);
        TypeInfo typeInfo = TypeInfo.of(typeClosure);
        Class superClass = typeInfo.getSuperClass();
        superClass = superClass == null ? Object.class : superClass;
        if (forceSuperClass || (superClass.equals(Object.class) && additionalInterfaces.isEmpty())) {
            // No interface beans must use the bean impl as superclass
            superClass = proxiedBeanType;
        }
        this.beanType = superClass;

        addDefaultAdditionalInterfaces();
        baseProxyName = proxyName;
        if (bean != null) {
            /*
             * this may happen when creating an InjectionTarget for a decorator using BeanManager#createInjectionTarget()
             * which does not allow the bean to be specified
             */
            this.classLoader = resolveClassLoaderForBeanProxy(contextId, bean.getBeanClass(), typeInfo);
        } else {
            this.classLoader = resolveClassLoaderForBeanProxy(contextId, proxiedBeanType, typeInfo);
        }
        // hierarchy order
        if (additionalInterfaces.size() > 1) {
            LinkedHashSet> sorted = Proxies.sortInterfacesHierarchy(additionalInterfaces);
            additionalInterfaces.clear();
            additionalInterfaces.addAll(sorted);
        }

        this.proxyInstantiator = Container.instance(contextId).services().get(ProxyInstantiator.class);
    }

    static String getProxyName(String contextId, Class proxiedBeanType, Set typeClosure, Bean bean) {
        TypeInfo typeInfo = TypeInfo.of(typeClosure);
        String proxyPackage;
        if (proxiedBeanType.equals(Object.class)) {
            Class superInterface = typeInfo.getSuperInterface();
            if (superInterface == null) {
                throw new IllegalArgumentException("Proxied bean type cannot be java.lang.Object without an interface");
            } else {
                if (superInterface.getPackage() == null) {
                    proxyPackage = DEFAULT_PROXY_PACKAGE;
                } else {
                    proxyPackage = superInterface.getPackage().getName();
                }
            }
        } else {
            if (proxiedBeanType.getPackage() == null) {
                proxyPackage = DEFAULT_PROXY_PACKAGE;
            } else {
                proxyPackage = proxiedBeanType.getPackage().getName();
            }
        }
        final String className;

        if (typeInfo.getSuperClass() == Object.class) {
            final StringBuilder name = new StringBuilder();
            //interface only bean.
            className = createCompoundProxyName(contextId, bean, typeInfo, name) + PROXY_SUFFIX;
        } else {
            boolean typeModified = false;
            for (Class iface : typeInfo.getInterfaces()) {
                if (!iface.isAssignableFrom(typeInfo.getSuperClass())) {
                    typeModified = true;
                    break;
                }
            }
            if (typeModified) {
                //this bean has interfaces that the base type is not assignable to
                //which can happen with some creative use of the SPI
                //interface only bean.
                StringBuilder name = new StringBuilder(typeInfo.getSuperClass().getSimpleName() + "$");
                className = createCompoundProxyName(contextId, bean, typeInfo, name) + PROXY_SUFFIX;
            } else {
                className = typeInfo.getSuperClass().getSimpleName() + PROXY_SUFFIX;
            }
        }

        return proxyPackage + '.' + getEnclosingPrefix(proxiedBeanType) + className;
    }

    public void addInterfacesFromTypeClosure(Set typeClosure, Class proxiedBeanType) {
        for (Type type : typeClosure) {
            Class c = Reflections.getRawType(type);
            // Ignore no-interface views, they are dealt with proxiedBeanType
            // (pending redesign)
            if (c.isInterface()) {
                addInterface(c);
            }
        }
    }

    private static String createCompoundProxyName(String contextId, Bean bean, TypeInfo typeInfo, StringBuilder name) {
        String className;
        final List interfaces = new ArrayList();
        for (Class type : typeInfo.getInterfaces()) {
            interfaces.add(type.getSimpleName());
        }
        Collections.sort(interfaces);
        for (final String iface : interfaces) {
            name.append(iface);
            name.append('$');
        }
        //there is a remote chance that this could generate the same
        //proxy name for two interfaces with the same simple name.
        //append the hash code of the bean id to be sure
        // However, it is safe to share a proxy class for built-in beans of the same type (e.g. Event)
        if (bean != null && !(bean instanceof AbstractBuiltInBean)) {
            final BeanIdentifier id = Container.instance(contextId).services().get(ContextualStore.class).putIfAbsent(bean);
            int idHash = id.hashCode();
            name.append(Math.abs(idHash == Integer.MIN_VALUE ? 0 : idHash));
        }
        className = name.toString();
        return className;
    }

    private static String getEnclosingPrefix(Class clazz) {
        Class encl = clazz.getEnclosingClass();
        return encl == null ? "" : getEnclosingPrefix(encl) + encl.getSimpleName() + '$';
    }

    /**
     * Adds an additional interface that the proxy should implement. The default
     * implementation will be to forward invocations to the bean instance.
     *
     * @param newInterface an interface
     */
    public void addInterface(Class newInterface) {
        if (!newInterface.isInterface()) {
            throw new IllegalArgumentException(newInterface + " is not an interface");
        }
        additionalInterfaces.add(newInterface);
    }

    /**
     * Method to create a new proxy that wraps the bean instance.
     *
     * @param beanInstance the bean instance
     * @return a new proxy object
     */
    public T create(BeanInstance beanInstance) {
        final T proxy = (System.getSecurityManager() == null) ? run() : AccessController.doPrivileged(this);
        ((ProxyObject) proxy).setHandler(new ProxyMethodHandler(contextId, beanInstance, bean));
        return proxy;
    }

    @Override
    public T run() {
        try {
            return proxyInstantiator.newInstance(getProxyClass());
        } catch (InstantiationException e) {
            throw new DefinitionException(BeanLogger.LOG.proxyInstantiationFailed(this), e.getCause());
        } catch (IllegalAccessException e) {
            throw new DefinitionException(BeanLogger.LOG.proxyInstantiationBeanAccessFailed(this), e.getCause());
        }
    }

    /**
     * Produces or returns the existing proxy class. The operation is thread-safe.
     *
     * @return always the class of the proxy
     */
    public Class getProxyClass() {
        String suffix = "_$$_Weld" + getProxyNameSuffix();
        String proxyClassName = getBaseProxyName();
        if (!proxyClassName.endsWith(suffix)) {
            proxyClassName = proxyClassName + suffix;
        }
        if (proxyClassName.startsWith(JAVA)) {
            proxyClassName = proxyClassName.replaceFirst(JAVA, "org.jboss.weld");
        }
        Class proxyClass = null;
        BeanLogger.LOG.generatingProxyClass(proxyClassName);
        try {
            // First check to see if we already have this proxy class
            proxyClass = cast(classLoader.loadClass(proxyClassName));
        } catch (ClassNotFoundException e) {
            // Create the proxy class for this instance
            try {
                proxyClass = createProxyClass(proxyClassName);
            } catch (Throwable e1) {
                //attempt to load the class again, just in case another thread
                //defined it between the check and the create method
                try {
                    proxyClass = cast(classLoader.loadClass(proxyClassName));
                } catch (ClassNotFoundException e2) {
                    BeanLogger.LOG.catchingDebug(e1);
                    throw BeanLogger.LOG.unableToLoadProxyClass(bean, proxiedBeanType, classLoader, e1);
                }
            }
        }
        return proxyClass;
    }

    /**
     * Returns the package and base name for the proxy class.
     *
     * @return base name without suffixes
     */
    protected String getBaseProxyName() {
        return baseProxyName;
    }

    /**
     * Convenience method to determine if an object is a proxy generated by this
     * factory or any derived factory.
     *
     * @param proxySuspect the object suspected of being a proxy
     * @return true only if it is a proxy object
     */
    public static boolean isProxy(Object proxySuspect) {
        return proxySuspect instanceof ProxyObject;
    }

    /**
     * Convenience method to set the underlying bean instance for a proxy.
     *
     * @param proxy        the proxy instance
     * @param beanInstance the instance of the bean
     */
    public static  void setBeanInstance(String contextId, T proxy, BeanInstance beanInstance, Bean bean) {
        if (proxy instanceof ProxyObject) {
            ProxyObject proxyView = (ProxyObject) proxy;
            proxyView.setHandler(new ProxyMethodHandler(contextId, beanInstance, bean));
        }
    }

    /**
     * Returns a suffix to append to the name of the proxy class. The name
     * already consists of _$$_Weld, to which the suffix is added.
     * This allows the creation of different types of proxies for the same class.
     *
     * @return a name suffix
     */
    protected String getProxyNameSuffix() {
        return PROXY_SUFFIX;
    }

    private void addDefaultAdditionalInterfaces() {
        additionalInterfaces.add(Serializable.class);
    }

    /**
     * Sub classes may override to specify additional interfaces the proxy should
     * implement
     */
    protected void addAdditionalInterfaces(Set> interfaces) {

    }

    private Class createProxyClass(String proxyClassName) throws Exception {
        Set> specialInterfaces = Sets.newHashSet(
                LifecycleMixin.class, TargetInstanceProxy.class, ProxyObject.class);
        addAdditionalInterfaces(specialInterfaces);
        // Remove special interfaces from main set (deserialization scenario)
        additionalInterfaces.removeAll(specialInterfaces);

        ClassFile proxyClassType = null;
        final int accessFlags = AccessFlag.of(AccessFlag.PUBLIC, AccessFlag.SUPER, AccessFlag.SYNTHETIC);
        if (getBeanType().isInterface()) {
            proxyClassType = newClassFile(proxyClassName, accessFlags, Object.class.getName());
            proxyClassType.addInterface(getBeanType().getName());
        } else {
            proxyClassType = newClassFile(proxyClassName, accessFlags, getBeanType().getName());
        }
        // Add interfaces which require method generation
        for (Class clazz : additionalInterfaces) {
            proxyClassType.addInterface(clazz.getName());
        }
        List initialValueBytecode = new ArrayList();

        // Workaround for IBM JVM - the ACC_STATIC flag should only be required for class file with version number 51.0 or above
        ClassMethod staticConstructor = proxyClassType.addMethod(AccessFlag.of(AccessFlag.PUBLIC, AccessFlag.STATIC), "", "V");

        addFields(proxyClassType, initialValueBytecode);
        addConstructors(proxyClassType, initialValueBytecode);
        addMethods(proxyClassType, staticConstructor);

        staticConstructor.getCodeAttribute().returnInstruction();

        // Additional interfaces whose methods require special handling
        for (Class specialInterface : specialInterfaces) {
            proxyClassType.addInterface(specialInterface.getName());
        }
        // TODO: change the ProxyServices SPI to allow the container to figure out
        // which PD to use

        // Dump proxy type bytecode if necessary
        dumpToFile(proxyClassName, proxyClassType.toBytecode());

        ProtectionDomain domain = AccessController.doPrivileged(new GetProtectionDomainAction(proxiedBeanType));

        if (proxiedBeanType.getPackage() == null || proxiedBeanType.equals(Object.class)) {
            domain = ProxyFactory.class.getProtectionDomain();
        } else if (System.getSecurityManager() != null) {
            ProtectionDomainCache cache = Container.instance(contextId).services().get(ProtectionDomainCache.class);
            domain = cache.getProtectionDomainForProxy(domain);
        }
        Class proxyClass = cast(ClassFileUtils.toClass(proxyClassType, classLoader, domain));
        BeanLogger.LOG.createdProxyClass(proxyClass, Arrays.toString(proxyClass.getInterfaces()));
        return proxyClass;
    }

    private ClassFile newClassFile(String name, int accessFlags, String superclass, String... interfaces) {
        try {
            if (CONFIGURABLE_CLASSLOADER_CONSTRUCTOR != null) {
                return CONFIGURABLE_CLASSLOADER_CONSTRUCTOR.newInstance(name, accessFlags, superclass, classLoader, interfaces);
            } else if (CONFIGURABLE_ACCESS_FLAGS) {
                return new ClassFile(name, accessFlags, superclass, interfaces);
            } else {
                return new ClassFile(name, superclass, interfaces);
            }
        } catch (Exception e) {
            throw BeanLogger.LOG.unableToCreateClassFile(name, e.getCause());
        }
    }

    private void dumpToFile(String fileName, byte[] data) {
        File proxyDumpFilePath = configuration.getProxyDumpFilePath();
        if (proxyDumpFilePath == null) {
            return;
        }
        FileOutputStream dumpFileStream = null;
        File classFile = new File(proxyDumpFilePath, fileName + ".class");
        try {
            if (classFile.isFile()) {
                if (!classFile.delete()) {
                    throw new IOException("Can not to remove file: " + classFile.getName());
                }
            }
            dumpFileStream = new FileOutputStream(classFile);
            dumpFileStream.write(data);
        } catch (IOException e) {
            BeanLogger.LOG.beanCannotBeDumped(fileName, e);
        } finally {
            try {
                if (dumpFileStream != null) {
                    dumpFileStream.close();
                }
            } catch (IOException e) {
                BeanLogger.LOG.beanCannotBeDumped(fileName, e);
            }
        }
    }

    /**
     * Adds a constructor for the proxy for each constructor declared by the base
     * bean type.
     *
     * @param proxyClassType       the Javassist class for the proxy
     * @param initialValueBytecode
     */
    protected void addConstructors(ClassFile proxyClassType, List initialValueBytecode) {
        try {
            if (getBeanType().isInterface()) {
                ConstructorUtils.addDefaultConstructor(proxyClassType, initialValueBytecode, !proxyInstantiator.isUsingConstructor());
            } else {
                boolean constructorFound = false;
                for (Constructor constructor : AccessController.doPrivileged(new GetDeclaredConstructorsAction(getBeanType()))) {
                    if ((constructor.getModifiers() & Modifier.PRIVATE) == 0) {
                        constructorFound = true;
                        String[] exceptions = new String[constructor.getExceptionTypes().length];
                        for (int i = 0; i < exceptions.length; ++i) {
                            exceptions[i] = constructor.getExceptionTypes()[i].getName();
                        }
                        ConstructorUtils.addConstructor(BytecodeUtils.VOID_CLASS_DESCRIPTOR, DescriptorUtils.parameterDescriptors(constructor.getParameterTypes()), exceptions, proxyClassType, initialValueBytecode, !proxyInstantiator.isUsingConstructor());
                    }
                }
                if (!constructorFound) {
                    // the bean only has private constructors, we need to generate
                    // two fake constructors that call each other
                    addConstructorsForBeanWithPrivateConstructors(proxyClassType);
                }
            }
        } catch (Exception e) {
            throw new WeldException(e);
        }
    }

    protected void addFields(ClassFile proxyClassType, List initialValueBytecode) {
        // The field representing the underlying instance or special method
        // handling
        proxyClassType.addField(AccessFlag.PRIVATE, METHOD_HANDLER_FIELD_NAME, getMethodHandlerType());
        if (proxyInstantiator.isUsingConstructor()) {
            // field used to indicate that super() has been called
            proxyClassType.addField(AccessFlag.PRIVATE, CONSTRUCTED_FLAG_NAME, BytecodeUtils.BOOLEAN_CLASS_DESCRIPTOR);
        }
    }

    protected Class getMethodHandlerType() {
        return MethodHandler.class;
    }

    protected void addMethods(ClassFile proxyClassType, ClassMethod staticConstructor) {
        // Add all class methods for interception
        addMethodsFromClass(proxyClassType, staticConstructor);

        // Add special proxy methods
        addSpecialMethods(proxyClassType, staticConstructor);

        // Add serialization support methods
        addSerializationSupport(proxyClassType);
    }

    /**
     * Adds special serialization code. By default this is a nop
     *
     * @param proxyClassType the Javassist class for the proxy class
     */
    protected void addSerializationSupport(ClassFile proxyClassType) {
        //noop
    }

    protected void addMethodsFromClass(ClassFile proxyClassType, ClassMethod staticConstructor) {
        try {
            // Add all methods from the class hierarchy
            Class cls = getBeanType();

            // First add equals/hashCode methods if required
            generateEqualsMethod(proxyClassType);
            generateHashCodeMethod(proxyClassType);

            // In rare cases, the bean class may be abstract - in this case we have to add methods from all interfaces implemented by any abstract class
            // from the hierarchy
            boolean isBeanClassAbstract = Modifier.isAbstract(cls.getModifiers());

            while (cls != null) {
                addMethods(cls, proxyClassType, staticConstructor);
                if (isBeanClassAbstract && Modifier.isAbstract(cls.getModifiers())) {
                    for (Class implementedInterface : Reflections.getInterfaceClosure(cls)) {
                        if (!additionalInterfaces.contains(implementedInterface)) {
                            addMethods(implementedInterface, proxyClassType, staticConstructor);
                        }
                    }
                }
                cls = cls.getSuperclass();
            }
            for (Class c : additionalInterfaces) {
                for (Method method : c.getMethods()) {
                    if (isMethodAccepted(method, getProxySuperclass())) {
                        try {
                            MethodInformation methodInfo = new RuntimeMethodInformation(method);
                            ClassMethod classMethod = proxyClassType.addMethod(method);
                            if (Reflections.isDefault(method)) {
                                addConstructedGuardToMethodBody(classMethod);
                                createForwardingMethodBody(classMethod, methodInfo, staticConstructor);
                            } else {
                                createSpecialMethodBody(classMethod, methodInfo, staticConstructor);
                            }
                            BeanLogger.LOG.addingMethodToProxy(method);
                        } catch (DuplicateMemberException e) {
                        }
                    }
                }
            }
        } catch (Exception e) {
            throw new WeldException(e);
        }
    }

    private void addMethods(Class cls, ClassFile proxyClassType, ClassMethod staticConstructor) {
        for (Method method : AccessController.doPrivileged(new GetDeclaredMethodsAction(cls))) {
            if (isMethodAccepted(method, getProxySuperclass())) {
                try {
                    MethodInformation methodInfo = new RuntimeMethodInformation(method);
                    ClassMethod classMethod = proxyClassType.addMethod(method);
                    addConstructedGuardToMethodBody(classMethod);
                    createForwardingMethodBody(classMethod, methodInfo, staticConstructor);
                    BeanLogger.LOG.addingMethodToProxy(method);
                } catch (DuplicateMemberException e) {
                    // do nothing. This will happen if superclass methods
                    // have been overridden
                }
            }
        }
    }

    protected boolean isMethodAccepted(Method method, Class proxySuperclass) {
        for (ProxiedMethodFilter filter : METHOD_FILTERS) {
            if (!filter.accept(method, proxySuperclass)) {
                return false;
            }
        }
        return true;
    }

    /**
     * Generate the body of the proxies hashCode method.
     * 

* If this method returns null, the method will not be added, and the * hashCode on the superclass will be used as per normal virtual method * resolution rules */ protected void generateHashCodeMethod(ClassFile proxyClassType) { } /** * Generate the body of the proxies equals method. *

* If this method returns null, the method will not be added, and the * hashCode on the superclass will be used as per normal virtual method * resolution rules * * @param proxyClassType The class file */ protected void generateEqualsMethod(ClassFile proxyClassType) { } protected void createSpecialMethodBody(ClassMethod proxyClassType, MethodInformation method, ClassMethod staticConstructor) { createInterceptorBody(proxyClassType, method, staticConstructor); } protected void addConstructedGuardToMethodBody(final ClassMethod classMethod) { addConstructedGuardToMethodBody(classMethod, classMethod.getClassFile().getSuperclass()); } /** * Adds the following code to a delegating method: *

* * if(!this.constructed) return super.thisMethod() * *

* This means that the proxy will not start to delegate to the underlying * bean instance until after the constructor has finished. */ protected void addConstructedGuardToMethodBody(final ClassMethod classMethod, String className) { if (!proxyInstantiator.isUsingConstructor()) { return; } // now create the conditional final CodeAttribute cond = classMethod.getCodeAttribute(); cond.aload(0); cond.getfield(classMethod.getClassFile().getName(), CONSTRUCTED_FLAG_NAME, BytecodeUtils.BOOLEAN_CLASS_DESCRIPTOR); // jump if the proxy constructor has finished BranchEnd jumpMarker = cond.ifne(); // generate the invokespecial call to the super class method // this is run when the proxy is being constructed cond.aload(0); cond.loadMethodParameters(); cond.invokespecial(className, classMethod.getName(), classMethod.getDescriptor()); cond.returnInstruction(); cond.branchEnd(jumpMarker); } protected void createForwardingMethodBody(ClassMethod classMethod, MethodInformation method, ClassMethod staticConstructor) { createInterceptorBody(classMethod, method, staticConstructor); } /** * Creates the given method on the proxy class where the implementation * forwards the call directly to the method handler. *

* the generated bytecode is equivalent to: *

* return (RetType) methodHandler.invoke(this,param1,param2); * * @param classMethod the class method * @param method any JLR method * @return the method byte code */ protected void createInterceptorBody(ClassMethod classMethod, MethodInformation method, ClassMethod staticConstructor) { invokeMethodHandler(classMethod, method, true, DEFAULT_METHOD_RESOLVER, staticConstructor); } /** * calls methodHandler.invoke for a given method * * @param method The method information * @param addReturnInstruction set to true you want to return the result of * the method invocation * @param bytecodeMethodResolver The resolver that returns the method to invoke */ protected void invokeMethodHandler(ClassMethod classMethod, MethodInformation method, boolean addReturnInstruction, BytecodeMethodResolver bytecodeMethodResolver, ClassMethod staticConstructor) { // now we need to build the bytecode. The order we do this in is as // follows: // load methodHandler // load this // load the method object // load null // create a new array the same size as the number of parameters // push our parameter values into the array // invokeinterface the invoke method // add checkcast to cast the result to the return type, or unbox if // primitive // add an appropriate return instruction final CodeAttribute b = classMethod.getCodeAttribute(); b.aload(0); getMethodHandlerField(classMethod.getClassFile(), b); b.aload(0); bytecodeMethodResolver.getDeclaredMethod(classMethod, method.getDeclaringClass(), method.getName(), method.getParameterTypes(), staticConstructor); b.aconstNull(); b.iconst(method.getParameterTypes().length); b.anewarray("java.lang.Object"); int localVariableCount = 1; for (int i = 0; i < method.getParameterTypes().length; ++i) { String typeString = method.getParameterTypes()[i]; b.dup(); // duplicate the array reference b.iconst(i); // load the parameter value BytecodeUtils.addLoadInstruction(b, typeString, localVariableCount); // box the parameter if necessary Boxing.boxIfNessesary(b, typeString); // and store it in the array b.aastore(); if (isWide(typeString)) { localVariableCount = localVariableCount + 2; } else { localVariableCount++; } } // now we have all our arguments on the stack // lets invoke the method b.invokeinterface(MethodHandler.class.getName(), "invoke", LJAVA_LANG_OBJECT, new String[] { LJAVA_LANG_OBJECT, LJAVA_LANG_REFLECT_METHOD, LJAVA_LANG_REFLECT_METHOD, "[" + LJAVA_LANG_OBJECT }); if (addReturnInstruction) { // now we need to return the appropriate type if (method.getReturnType().equals(BytecodeUtils.VOID_CLASS_DESCRIPTOR)) { b.returnInstruction(); } else if(isPrimitive(method.getReturnType())) { Boxing.unbox(b, method.getReturnType()); b.returnInstruction(); } else { b.checkcast(BytecodeUtils.getName(method.getReturnType())); b.returnInstruction(); } } } /** * Adds methods requiring special implementations rather than just * delegation. * * @param proxyClassType the Javassist class description for the proxy type */ protected void addSpecialMethods(ClassFile proxyClassType, ClassMethod staticConstructor) { try { // Add special methods for interceptors for (Method method : LifecycleMixin.class.getMethods()) { BeanLogger.LOG.addingMethodToProxy(method); MethodInformation methodInfo = new RuntimeMethodInformation(method); final ClassMethod classMethod = proxyClassType.addMethod(method); createInterceptorBody(classMethod, methodInfo, staticConstructor); } Method getInstanceMethod = TargetInstanceProxy.class.getMethod("getTargetInstance"); Method getInstanceClassMethod = TargetInstanceProxy.class.getMethod("getTargetClass"); MethodInformation getInstanceMethodInfo = new RuntimeMethodInformation(getInstanceMethod); createInterceptorBody(proxyClassType.addMethod(getInstanceMethod), getInstanceMethodInfo, staticConstructor); MethodInformation getInstanceClassMethodInfo = new RuntimeMethodInformation(getInstanceClassMethod); createInterceptorBody(proxyClassType.addMethod(getInstanceClassMethod), getInstanceClassMethodInfo, staticConstructor); Method setMethodHandlerMethod = ProxyObject.class.getMethod("setHandler", MethodHandler.class); generateSetMethodHandlerBody(proxyClassType.addMethod(setMethodHandlerMethod)); Method getMethodHandlerMethod = ProxyObject.class.getMethod("getHandler"); generateGetMethodHandlerBody(proxyClassType.addMethod(getMethodHandlerMethod)); } catch (Exception e) { throw new WeldException(e); } } protected void generateSetMethodHandlerBody(ClassMethod method) { final CodeAttribute b = method.getCodeAttribute(); b.aload(0); b.aload(1); b.checkcast(getMethodHandlerType()); b.putfield(method.getClassFile().getName(), METHOD_HANDLER_FIELD_NAME, DescriptorUtils.makeDescriptor(getMethodHandlerType())); b.returnInstruction(); } protected void generateGetMethodHandlerBody(ClassMethod method) { final CodeAttribute b = method.getCodeAttribute(); b.aload(0); getMethodHandlerField(method.getClassFile(), b); b.returnInstruction(); } /** * Adds two constructors to the class that call each other in order to bypass * the JVM class file verifier. *

* This would result in a stack overflow if they were actually called, * however the proxy is directly created without calling the constructor */ private void addConstructorsForBeanWithPrivateConstructors(ClassFile proxyClassType) { ClassMethod ctor = proxyClassType.addMethod(AccessFlag.PUBLIC, INIT_METHOD_NAME, BytecodeUtils.VOID_CLASS_DESCRIPTOR, LJAVA_LANG_BYTE); CodeAttribute b = ctor.getCodeAttribute(); b.aload(0); b.aconstNull(); b.aconstNull(); b.invokespecial(proxyClassType.getName(), INIT_METHOD_NAME, "(" + LJAVA_LANG_BYTE + LJAVA_LANG_BYTE + ")" + BytecodeUtils.VOID_CLASS_DESCRIPTOR); b.returnInstruction(); ctor = proxyClassType.addMethod(AccessFlag.PUBLIC, INIT_METHOD_NAME, BytecodeUtils.VOID_CLASS_DESCRIPTOR, LJAVA_LANG_BYTE, LJAVA_LANG_BYTE); b = ctor.getCodeAttribute(); b.aload(0); b.aconstNull(); b.invokespecial(proxyClassType.getName(), INIT_METHOD_NAME, "(" + LJAVA_LANG_BYTE + ")" + BytecodeUtils.VOID_CLASS_DESCRIPTOR); b.returnInstruction(); } public Class getBeanType() { return beanType; } public Set> getAdditionalInterfaces() { return additionalInterfaces; } public Bean getBean() { return bean; } public String getContextId() { return contextId; } /** * Figures out the correct class loader to use for a proxy for a given bean */ public static ClassLoader resolveClassLoaderForBeanProxy(String contextId, Class proxiedType, TypeInfo typeInfo) { Class superClass = typeInfo.getSuperClass(); if (superClass.getName().startsWith(JAVA)) { ClassLoader cl = Container.instance(contextId).services().get(ProxyServices.class).getClassLoader(proxiedType); if (cl == null) { cl = Thread.currentThread().getContextClassLoader(); } return cl; } return Container.instance(contextId).services().get(ProxyServices.class).getClassLoader(superClass); } protected void getMethodHandlerField(ClassFile file, CodeAttribute b) { b.getfield(file.getName(), METHOD_HANDLER_FIELD_NAME, DescriptorUtils.makeDescriptor(getMethodHandlerType())); } private Class getProxySuperclass() { return getBeanType().isInterface() ? Object.class : getBeanType(); } }





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