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- /*
- * Javassist, a Java-bytecode translator toolkit.
- * Copyright (C) 1999- Shigeru Chiba. All Rights Reserved.
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (the "License"); you may not use this file except in compliance with
- * the License. Alternatively, the contents of this file may be used under
- * the terms of the GNU Lesser General Public License Version 2.1 or later,
- * or the Apache License Version 2.0.
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- */
-
- package javassist.util.proxy;
-
- import java.lang.ref.Reference;
- import java.lang.ref.WeakReference;
- import java.lang.reflect.Constructor;
- import java.lang.reflect.Field;
- import java.lang.reflect.InvocationTargetException;
- import java.lang.reflect.Member;
- import java.lang.reflect.Method;
- import java.lang.reflect.Modifier;
- import java.security.ProtectionDomain;
- import java.util.ArrayList;
- import java.util.Collections;
- import java.util.Comparator;
- import java.util.HashMap;
- import java.util.HashSet;
- import java.util.Iterator;
- import java.util.List;
- import java.util.Map;
- import java.util.Set;
- import java.util.WeakHashMap;
-
- import javassist.CannotCompileException;
- import javassist.bytecode.AccessFlag;
- import javassist.bytecode.Bytecode;
- import javassist.bytecode.ClassFile;
- import javassist.bytecode.CodeAttribute;
- import javassist.bytecode.ConstPool;
- import javassist.bytecode.Descriptor;
- import javassist.bytecode.DuplicateMemberException;
- import javassist.bytecode.ExceptionsAttribute;
- import javassist.bytecode.FieldInfo;
- import javassist.bytecode.MethodInfo;
- import javassist.bytecode.Opcode;
- import javassist.bytecode.StackMapTable;
-
- /*
- * This class is implemented only with the lower-level API of Javassist.
- * This design decision is for maximizing performance.
- */
-
- /**
- * Factory of dynamic proxy classes.
- *
- * <p>This factory generates a class that extends the given super class and implements
- * the given interfaces. The calls of the methods inherited from the super class are
- * forwarded and then <code>invoke()</code> is called on the method handler
- * associated with instances of the generated class. The calls of the methods from
- * the interfaces are also forwarded to the method handler.
- *
- * <p>For example, if the following code is executed,
- *
- * <pre>
- * ProxyFactory f = new ProxyFactory();
- * f.setSuperclass(Foo.class);
- * f.setFilter(new MethodFilter() {
- * public boolean isHandled(Method m) {
- * // ignore finalize()
- * return !m.getName().equals("finalize");
- * }
- * });
- * Class c = f.createClass();
- * MethodHandler mi = new MethodHandler() {
- * public Object invoke(Object self, Method m, Method proceed,
- * Object[] args) throws Throwable {
- * System.out.println("Name: " + m.getName());
- * return proceed.invoke(self, args); // execute the original method.
- * }
- * };
- * Foo foo = (Foo)c.newInstance();
- * ((Proxy)foo).setHandler(mi);
- * </pre>
- *
- * <p>Here, <code>Method</code> is <code>java.lang.reflect.Method</code>.</p>
- *
- * <p>Then, the following method call will be forwarded to MethodHandler
- * <code>mi</code> and prints a message before executing the originally called method
- * <code>bar()</code> in <code>Foo</code>.
- *
- * <pre>
- * foo.bar();
- * </pre>
- *
- * <p>The last three lines of the code shown above can be replaced with a call to
- * the helper method <code>create</code>, which generates a proxy class, instantiates
- * it, and sets the method handler of the instance:
- *
- * <pre>
- * :
- * Foo foo = (Foo)f.create(new Class[0], new Object[0], mi);
- * </pre>
- *
- * <p>To change the method handler during runtime,
- * execute the following code:
- *
- * <pre>
- * MethodHandler mi = ... ; // alternative handler
- * ((Proxy)foo).setHandler(mi);
- * </pre>
- *
- * <p> If setHandler is never called for a proxy instance then it will
- * employ the default handler which proceeds by invoking the original method.
- * The behaviour of the default handler is identical to the following
- * handler:
- *
- * <pre>
- * class EmptyHandler implements MethodHandler {
- * public Object invoke(Object self, Method m,
- * Method proceed, Object[] args) throws Exception {
- * return proceed.invoke(self, args);
- * }
- * }
- * </pre>
- *
- * <p>A proxy factory caches and reuses proxy classes by default. It is possible to reset
- * this default globally by setting static field {@link ProxyFactory#useCache} to false.
- * Caching may also be configured for a specific factory by calling instance method
- * {@link ProxyFactory#setUseCache(boolean)}. It is strongly recommended that new clients
- * of class ProxyFactory enable caching. Failure to do so may lead to exhaustion of
- * the heap memory area used to store classes.
- *
- * <p>Caching is automatically disabled for any given proxy factory if deprecated instance
- * method {@link ProxyFactory#setHandler(MethodHandler)} is called. This method was
- * used to specify a default handler which newly created proxy classes should install
- * when they create their instances. It is only retained to provide backward compatibility
- * with previous releases of javassist. Unfortunately,this legacy behaviour makes caching
- * and reuse of proxy classes impossible. The current programming model expects javassist
- * clients to set the handler of a proxy instance explicitly by calling method
- * {@link Proxy#setHandler(MethodHandler)} as shown in the sample code above. New
- * clients are strongly recommended to use this model rather than calling
- * {@link ProxyFactory#setHandler(MethodHandler)}.
- *
- * <p>A proxy object generated by <code>ProxyFactory</code> is serializable
- * if its super class or any of its interfaces implement <code>java.io.Serializable</code>.
- * However, a serialized proxy object may not be compatible with future releases.
- * The serialization support should be used for short-term storage or RMI.
- *
- * <p>For compatibility with older releases serialization of proxy objects is implemented by
- * adding a writeReplace method to the proxy class. This allows a proxy to be serialized
- * to a conventional {@link java.io.ObjectOutputStream} and deserialized from a corresponding
- * {@link java.io.ObjectInputStream}. However this method suffers from several problems, the most
- * notable one being that it fails to serialize state inherited from the proxy's superclass.
- * <p>
- * An alternative method of serializing proxy objects is available which fixes these problems. It
- * requires inhibiting generation of the writeReplace method and instead using instances of
- * {@link javassist.util.proxy.ProxyObjectOutputStream} and {@link javassist.util.proxy.ProxyObjectInputStream}
- * (which are subclasses of {@link java.io.ObjectOutputStream} and {@link java.io.ObjectInputStream})
- * to serialize and deserialize, respectively, the proxy. These streams recognise javassist proxies and ensure
- * that they are serialized and deserialized without the need for the proxy class to implement special methods
- * such as writeReplace. Generation of the writeReplace method can be disabled globally by setting static field
- * {@link ProxyFactory#useWriteReplace} to false. Alternatively, it may be
- * configured per factory by calling instance method {@link ProxyFactory#setUseWriteReplace(boolean)}.
- *
- * @see MethodHandler
- * @since 3.1
- * @author Muga Nishizawa
- * @author Shigeru Chiba
- * @author Andrew Dinn
- */
- public class ProxyFactory {
- private Class<?> superClass;
- private Class<?>[] interfaces;
- private MethodFilter methodFilter;
- private MethodHandler handler; // retained for legacy usage
- private List<Map.Entry<String,Method>> signatureMethods;
- private boolean hasGetHandler;
- private byte[] signature;
- private String classname;
- private String basename;
- private String superName;
- private Class<?> thisClass;
- /**
- * per factory setting initialised from current setting for useCache but able to be reset before each create call
- */
- private boolean factoryUseCache;
- /**
- * per factory setting initialised from current setting for useWriteReplace but able to be reset before each create call
- */
- private boolean factoryWriteReplace;
-
- /**
- * <p>If true, only public/protected methods are forwarded to a proxy object.
- * The class for that proxy object is loaded by the {@code defineClass} method
- * in {@code java.lang.invoke.MethodHandles.Lookup}, which is available in
- * Java 9 or later. This works even when {@code sun.misc.Unsafe} is not
- * available for some reasons (it is already deprecated in Java 9).</p>
- *
- * <p>To load a class, Javassist first tries to use {@code sun.misc.Unsafe} and,
- * if not available, it uses a {@code protected} method in {@code java.lang.ClassLoader}
- * via {@code PrivilegedAction}. Since the latter approach is not available
- * any longer by default in Java 9 or later, the JVM argument
- * {@code --add-opens java.base/java.lang=ALL-UNNAMED} must be given to the JVM
- * when it is used (because of lack of {@code sun.misc.Unsafe}).
- * If this argument cannot be given to the JVM, {@code onlyPublicMethods} should
- * be set to {@code true}. Javassist will try to load by using
- * {@code java.lang.invoke.MethodHandles.Lookup}.</p>
- *
- * <p>The default value is {@code false}.</p>
- *
- * @see DefineClassHelper#toClass(String, ClassLoader, ProtectionDomain, byte[])
- * @since 3.22
- */
- public static boolean onlyPublicMethods = false;
-
- /**
- * If the value of this variable is not null, the class file of
- * the generated proxy class is written under the directory specified
- * by this variable. For example, if the value is
- * <code>"."</code>, then the class file is written under the current
- * directory. This method is for debugging.
- *
- * <p>The default value is null.
- */
- public String writeDirectory;
-
- private static final Class<?> OBJECT_TYPE = Object.class;
-
- private static final String HOLDER = "_methods_";
- private static final String HOLDER_TYPE = "[Ljava/lang/reflect/Method;";
- private static final String FILTER_SIGNATURE_FIELD = "_filter_signature";
- private static final String FILTER_SIGNATURE_TYPE = "[B";
- private static final String HANDLER = "handler";
- private static final String NULL_INTERCEPTOR_HOLDER = "javassist.util.proxy.RuntimeSupport";
- private static final String DEFAULT_INTERCEPTOR = "default_interceptor";
- private static final String HANDLER_TYPE
- = 'L' + MethodHandler.class.getName().replace('.', '/') + ';';
- private static final String HANDLER_SETTER = "setHandler";
- private static final String HANDLER_SETTER_TYPE = "(" + HANDLER_TYPE + ")V";
-
- private static final String HANDLER_GETTER = "getHandler";
- private static final String HANDLER_GETTER_TYPE = "()" + HANDLER_TYPE;
-
- private static final String SERIAL_VERSION_UID_FIELD = "serialVersionUID";
- private static final String SERIAL_VERSION_UID_TYPE = "J";
- private static final long SERIAL_VERSION_UID_VALUE = -1L;
-
- /**
- * If true, a generated proxy class is cached and it will be reused
- * when generating the proxy class with the same properties is requested.
- * The default value is true.
- *
- * Note that this value merely specifies the initial setting employed by any newly created
- * proxy factory. The factory setting may be overwritten by calling factory instance method
- * {@link #setUseCache(boolean)}
- *
- * @since 3.4
- */
- public static volatile boolean useCache = true;
-
- /**
- * If true, a generated proxy class will implement method writeReplace enabling
- * serialization of its proxies to a conventional ObjectOutputStream. this (default)
- * setting retains the old javassist behaviour which has the advantage that it
- * retains compatibility with older releases and requires no extra work on the part
- * of the client performing the serialization. However, it has the disadvantage that
- * state inherited from the superclasses of the proxy is lost during serialization.
- * if false then serialization/deserialization of the proxy instances will preserve
- * all fields. However, serialization must be performed via a {@link ProxyObjectOutputStream}
- * and deserialization must be via {@link ProxyObjectInputStream}. Any attempt to serialize
- * proxies whose class was created with useWriteReplace set to false via a normal
- * {@link java.io.ObjectOutputStream} will fail.
- *
- * Note that this value merely specifies the initial setting employed by any newly created
- * proxy factory. The factory setting may be overwritten by calling factory instance method
- * {@link #setUseWriteReplace(boolean)}
- *
- * @since 3.4
- */
- public static volatile boolean useWriteReplace = true;
-
- /*
- * methods allowing individual factory settings for factoryUseCache and factoryWriteReplace to be reset
- */
-
- /**
- * test whether this factory uses the proxy cache
- * @return true if this factory uses the proxy cache otherwise false
- */
- public boolean isUseCache()
- {
- return factoryUseCache;
- }
-
- /**
- * configure whether this factory should use the proxy cache
- * @param useCache true if this factory should use the proxy cache and false if it should not use the cache
- * @throws RuntimeException if a default interceptor has been set for the factory
- */
- public void setUseCache(boolean useCache)
- {
- // we cannot allow caching to be used if the factory is configured to install a default interceptor
- // field into generated classes
- if (handler != null && useCache) {
- throw new RuntimeException("caching cannot be enabled if the factory default interceptor has been set");
- }
- factoryUseCache = useCache;
- }
-
- /**
- * test whether this factory installs a writeReplace method in created classes
- * @return true if this factory installs a writeReplace method in created classes otherwise false
- */
- public boolean isUseWriteReplace()
- {
- return factoryWriteReplace;
- }
-
- /**
- * configure whether this factory should add a writeReplace method to created classes
- * @param useWriteReplace true if this factory should add a writeReplace method to created classes and false if it
- * should not add a writeReplace method
- */
- public void setUseWriteReplace(boolean useWriteReplace)
- {
- factoryWriteReplace = useWriteReplace;
- }
-
- private static Map<ClassLoader,Map<String,ProxyDetails>> proxyCache =
- new WeakHashMap<ClassLoader,Map<String,ProxyDetails>>();
-
- /**
- * determine if a class is a javassist proxy class
- * @param cl
- * @return true if the class is a javassist proxy class otherwise false
- */
- public static boolean isProxyClass(Class<?> cl)
- {
- // all proxies implement Proxy or ProxyObject. nothing else should.
- return (Proxy.class.isAssignableFrom(cl));
- }
-
- /**
- * used to store details of a specific proxy class in the second tier of the proxy cache. this entry
- * will be located in a hashmap keyed by the unique identifying name of the proxy class. the hashmap is
- * located in a weak hashmap keyed by the classloader common to all proxy classes in the second tier map.
- */
- static class ProxyDetails {
- /**
- * the unique signature of any method filter whose behaviour will be met by this class. each bit in
- * the byte array is set if the filter redirects the corresponding super or interface method and clear
- * if it does not redirect it.
- */
- byte[] signature;
- /**
- * a hexadecimal string representation of the signature bit sequence. this string also forms part
- * of the proxy class name.
- */
- Reference<Class<?>> proxyClass;
- /**
- * a flag which is true this class employs writeReplace to perform serialization of its instances
- * and false if serialization must employ of a ProxyObjectOutputStream and ProxyObjectInputStream
- */
- boolean isUseWriteReplace;
-
- ProxyDetails(byte[] signature, Class<?> proxyClass, boolean isUseWriteReplace)
- {
- this.signature = signature;
- this.proxyClass = new WeakReference<Class<?>>(proxyClass);
- this.isUseWriteReplace = isUseWriteReplace;
- }
- }
-
- /**
- * Constructs a factory of proxy class.
- */
- public ProxyFactory() {
- superClass = null;
- interfaces = null;
- methodFilter = null;
- handler = null;
- signature = null;
- signatureMethods = null;
- hasGetHandler = false;
- thisClass = null;
- writeDirectory = null;
- factoryUseCache = useCache;
- factoryWriteReplace = useWriteReplace;
- }
-
- /**
- * Sets the super class of a proxy class.
- */
- public void setSuperclass(Class<?> clazz) {
- superClass = clazz;
- // force recompute of signature
- signature = null;
- }
-
- /**
- * Obtains the super class set by <code>setSuperclass()</code>.
- *
- * @since 3.4
- */
- public Class<?> getSuperclass() { return superClass; }
-
- /**
- * Sets the interfaces of a proxy class.
- */
- public void setInterfaces(Class<?>[] ifs) {
- interfaces = ifs;
- // force recompute of signature
- signature = null;
- }
-
- /**
- * Obtains the interfaces set by <code>setInterfaces</code>.
- *
- * @since 3.4
- */
- public Class<?>[] getInterfaces() { return interfaces; }
-
- /**
- * Sets a filter that selects the methods that will be controlled by a handler.
- */
- public void setFilter(MethodFilter mf) {
- methodFilter = mf;
- // force recompute of signature
- signature = null;
- }
-
- /**
- * Generates a proxy class using the current filter.
- */
- public Class<?> createClass() {
- if (signature == null) {
- computeSignature(methodFilter);
- }
- return createClass1();
- }
-
- /**
- * Generates a proxy class using the supplied filter.
- */
- public Class<?> createClass(MethodFilter filter) {
- computeSignature(filter);
- return createClass1();
- }
-
- /**
- * Generates a proxy class with a specific signature.
- * access is package local so ProxyObjectInputStream can use this
- * @param signature
- * @return
- */
- Class<?> createClass(byte[] signature)
- {
- installSignature(signature);
- return createClass1();
- }
-
- private Class<?> createClass1() {
- Class<?> result = thisClass;
- if (result == null) {
- ClassLoader cl = getClassLoader();
- synchronized (proxyCache) {
- if (factoryUseCache)
- createClass2(cl);
- else
- createClass3(cl);
-
- result = thisClass;
- // don't retain any unwanted references
- thisClass = null;
- }
- }
-
- return result;
- }
-
- private static char[] hexDigits =
- { '0', '1', '2', '3', '4', '5', '6', '7',
- '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
-
- public String getKey(Class<?> superClass, Class<?>[] interfaces, byte[] signature, boolean useWriteReplace)
- {
- StringBuffer sbuf = new StringBuffer();
- if (superClass != null){
- sbuf.append(superClass.getName());
- }
- sbuf.append(":");
- for (int i = 0; i < interfaces.length; i++) {
- sbuf.append(interfaces[i].getName());
- sbuf.append(":");
- }
- for (int i = 0; i < signature.length; i++) {
- byte b = signature[i];
- int lo = b & 0xf;
- int hi = (b >> 4) & 0xf;
- sbuf.append(hexDigits[lo]);
- sbuf.append(hexDigits[hi]);
- }
- if (useWriteReplace) {
- sbuf.append(":w");
- }
-
- return sbuf.toString();
- }
-
- private void createClass2(ClassLoader cl) {
- String key = getKey(superClass, interfaces, signature, factoryWriteReplace);
- /*
- * Excessive concurrency causes a large memory footprint and slows the
- * execution speed down (with JDK 1.5). Thus, we use a jumbo lock for
- * reducing concrrency.
- */
- // synchronized (proxyCache) {
- Map<String,ProxyDetails> cacheForTheLoader = proxyCache.get(cl);
- ProxyDetails details;
- if (cacheForTheLoader == null) {
- cacheForTheLoader = new HashMap<String,ProxyDetails>();
- proxyCache.put(cl, cacheForTheLoader);
- }
- details = cacheForTheLoader.get(key);
- if (details != null) {
- Reference<Class<?>> reference = details.proxyClass;
- thisClass = reference.get();
- if (thisClass != null) {
- return;
- }
- }
- createClass3(cl);
- details = new ProxyDetails(signature, thisClass, factoryWriteReplace);
- cacheForTheLoader.put(key, details);
- // }
- }
-
- private void createClass3(ClassLoader cl) {
- // we need a new class so we need a new class name
- allocateClassName();
-
- try {
- ClassFile cf = make();
- if (writeDirectory != null)
- FactoryHelper.writeFile(cf, writeDirectory);
-
- thisClass = FactoryHelper.toClass(cf, cl, getDomain());
- setField(FILTER_SIGNATURE_FIELD, signature);
- // legacy behaviour : we only set the default interceptor static field if we are not using the cache
- if (!factoryUseCache) {
- setField(DEFAULT_INTERCEPTOR, handler);
- }
- }
- catch (CannotCompileException e) {
- throw new RuntimeException(e.getMessage(), e);
- }
-
- }
-
- private void setField(String fieldName, Object value) {
- if (thisClass != null && value != null)
- try {
- Field f = thisClass.getField(fieldName);
- SecurityActions.setAccessible(f, true);
- f.set(null, value);
- SecurityActions.setAccessible(f, false);
- }
- catch (Exception e) {
- throw new RuntimeException(e);
- }
- }
-
- static byte[] getFilterSignature(Class<?> clazz) {
- return (byte[])getField(clazz, FILTER_SIGNATURE_FIELD);
- }
-
- private static Object getField(Class<?> clazz, String fieldName) {
- try {
- Field f = clazz.getField(fieldName);
- f.setAccessible(true);
- Object value = f.get(null);
- f.setAccessible(false);
- return value;
- }
- catch (Exception e) {
- throw new RuntimeException(e);
- }
- }
-
- /**
- * Obtains the method handler of the given proxy object.
- *
- * @param p a proxy object.
- * @return the method handler.
- * @since 3.16
- */
- public static MethodHandler getHandler(Proxy p) {
- try {
- Field f = p.getClass().getDeclaredField(HANDLER);
- f.setAccessible(true);
- Object value = f.get(p);
- f.setAccessible(false);
- return (MethodHandler)value;
- }
- catch (Exception e) {
- throw new RuntimeException(e);
- }
- }
-
- /**
- * A provider of class loaders.
- *
- * @see #classLoaderProvider
- * @since 3.4
- */
- public static interface ClassLoaderProvider {
- /**
- * Returns a class loader.
- *
- * @param pf a proxy factory that is going to obtain a class loader.
- */
- public ClassLoader get(ProxyFactory pf);
- }
-
- /**
- * A provider used by <code>createClass()</code> for obtaining
- * a class loader.
- * <code>get()</code> on this <code>ClassLoaderProvider</code> object
- * is called to obtain a class loader.
- *
- * <p>The value of this field can be updated for changing the default
- * implementation.
- *
- * <p>Example:
- * <pre>
- * ProxyFactory.classLoaderProvider = new ProxyFactory.ClassLoaderProvider() {
- * public ClassLoader get(ProxyFactory pf) {
- * return Thread.currentThread().getContextClassLoader();
- * }
- * };
- * </pre>
- *
- * @since 3.4
- */
- public static ClassLoaderProvider classLoaderProvider =
- new ClassLoaderProvider() {
- @Override
- public ClassLoader get(ProxyFactory pf) {
- return pf.getClassLoader0();
- }
- };
-
- protected ClassLoader getClassLoader() {
- return classLoaderProvider.get(this);
- }
-
- protected ClassLoader getClassLoader0() {
- ClassLoader loader = null;
- if (superClass != null && !superClass.getName().equals("java.lang.Object"))
- loader = superClass.getClassLoader();
- else if (interfaces != null && interfaces.length > 0)
- loader = interfaces[0].getClassLoader();
-
- if (loader == null) {
- loader = getClass().getClassLoader();
- // In case javassist is in the endorsed dir
- if (loader == null) {
- loader = Thread.currentThread().getContextClassLoader();
- if (loader == null)
- loader = ClassLoader.getSystemClassLoader();
- }
- }
-
- return loader;
- }
-
- protected ProtectionDomain getDomain() {
- Class<?> clazz;
- if (superClass != null && !superClass.getName().equals("java.lang.Object"))
- clazz = superClass;
- else if (interfaces != null && interfaces.length > 0)
- clazz = interfaces[0];
- else
- clazz = this.getClass();
-
- return clazz.getProtectionDomain();
- }
-
- /**
- * Creates a proxy class and returns an instance of that class.
- *
- * @param paramTypes parameter types for a constructor.
- * @param args arguments passed to a constructor.
- * @param mh the method handler for the proxy class.
- * @since 3.4
- */
- public Object create(Class<?>[] paramTypes, Object[] args, MethodHandler mh)
- throws NoSuchMethodException, IllegalArgumentException,
- InstantiationException, IllegalAccessException, InvocationTargetException
- {
- Object obj = create(paramTypes, args);
- ((Proxy)obj).setHandler(mh);
- return obj;
- }
-
- /**
- * Creates a proxy class and returns an instance of that class.
- *
- * @param paramTypes parameter types for a constructor.
- * @param args arguments passed to a constructor.
- */
- public Object create(Class<?>[] paramTypes, Object[] args)
- throws NoSuchMethodException, IllegalArgumentException,
- InstantiationException, IllegalAccessException, InvocationTargetException
- {
- Class<?> c = createClass();
- Constructor<?> cons = c.getConstructor(paramTypes);
- return cons.newInstance(args);
- }
-
- /**
- * Sets the default invocation handler. This invocation handler is shared
- * among all the instances of a proxy class unless another is explicitly
- * specified.
- * @deprecated since 3.12
- * use of this method is incompatible with proxy class caching.
- * instead clients should call method {@link Proxy#setHandler(MethodHandler)} to set the handler
- * for each newly created proxy instance.
- * calling this method will automatically disable caching of classes created by the proxy factory.
- */
- @Deprecated
- public void setHandler(MethodHandler mi) {
- // if we were using the cache and the handler is non-null then we must stop caching
- if (factoryUseCache && mi != null) {
- factoryUseCache = false;
- // clear any currently held class so we don't try to reuse it or set its handler field
- thisClass = null;
- }
- handler = mi;
- // this retains the behaviour of the old code which resets any class we were holding on to
- // this is probably not what is wanted
- setField(DEFAULT_INTERCEPTOR, handler);
- }
-
- /**
- * A unique class name generator.
- */
- public static interface UniqueName {
- /**
- * Returns a unique class name.
- *
- * @param classname the super class name of the proxy class.
- */
- String get(String classname);
- }
-
- /**
- * A unique class name generator.
- * Replacing this generator changes the algorithm to generate a
- * unique name. The <code>get</code> method does not have to be
- * a <code>synchronized</code> method since the access to this field
- * is mutually exclusive and thus thread safe.
- */
- public static UniqueName nameGenerator = new UniqueName() {
- private final String sep = "_$$_jvst" + Integer.toHexString(this.hashCode() & 0xfff) + "_";
- private int counter = 0;
-
- @Override
- public String get(String classname) {
- return classname + sep + Integer.toHexString(counter++);
- }
- };
-
- private static String makeProxyName(String classname) {
- synchronized (nameGenerator) {
- return nameGenerator.get(classname);
- }
- }
-
- private ClassFile make() throws CannotCompileException {
- ClassFile cf = new ClassFile(false, classname, superName);
- cf.setAccessFlags(AccessFlag.PUBLIC);
- setInterfaces(cf, interfaces, hasGetHandler ? Proxy.class : ProxyObject.class);
- ConstPool pool = cf.getConstPool();
-
- // legacy: we only add the static field for the default interceptor if caching is disabled
- if (!factoryUseCache) {
- FieldInfo finfo = new FieldInfo(pool, DEFAULT_INTERCEPTOR, HANDLER_TYPE);
- finfo.setAccessFlags(AccessFlag.PUBLIC | AccessFlag.STATIC);
- cf.addField(finfo);
- }
-
- // handler is per instance
- FieldInfo finfo2 = new FieldInfo(pool, HANDLER, HANDLER_TYPE);
- finfo2.setAccessFlags(AccessFlag.PRIVATE);
- cf.addField(finfo2);
-
- // filter signature is per class
- FieldInfo finfo3 = new FieldInfo(pool, FILTER_SIGNATURE_FIELD, FILTER_SIGNATURE_TYPE);
- finfo3.setAccessFlags(AccessFlag.PUBLIC | AccessFlag.STATIC);
- cf.addField(finfo3);
-
- // the proxy class serial uid must always be a fixed value
- FieldInfo finfo4 = new FieldInfo(pool, SERIAL_VERSION_UID_FIELD, SERIAL_VERSION_UID_TYPE);
- finfo4.setAccessFlags(AccessFlag.PUBLIC | AccessFlag.STATIC| AccessFlag.FINAL);
- cf.addField(finfo4);
-
- // HashMap allMethods = getMethods(superClass, interfaces);
- // int size = allMethods.size();
- makeConstructors(classname, cf, pool, classname);
-
- List<Find2MethodsArgs> forwarders = new ArrayList<Find2MethodsArgs>();
- int s = overrideMethods(cf, pool, classname, forwarders);
- addClassInitializer(cf, pool, classname, s, forwarders);
- addSetter(classname, cf, pool);
- if (!hasGetHandler)
- addGetter(classname, cf, pool);
-
- if (factoryWriteReplace) {
- try {
- cf.addMethod(makeWriteReplace(pool));
- }
- catch (DuplicateMemberException e) {
- // writeReplace() is already declared in the super class/interfaces.
- }
- }
-
- thisClass = null;
- return cf;
- }
-
- private void checkClassAndSuperName() {
- if (interfaces == null)
- interfaces = new Class[0];
-
- if (superClass == null) {
- superClass = OBJECT_TYPE;
- superName = superClass.getName();
- basename = interfaces.length == 0 ? superName
- : interfaces[0].getName();
- } else {
- superName = superClass.getName();
- basename = superName;
- }
-
- if (Modifier.isFinal(superClass.getModifiers()))
- throw new RuntimeException(superName + " is final");
-
- if (basename.startsWith("java.") || onlyPublicMethods)
- basename = "javassist.util.proxy." + basename.replace('.', '_');
- }
-
- private void allocateClassName() {
- classname = makeProxyName(basename);
- }
-
- private static Comparator<Map.Entry<String,Method>> sorter =
- new Comparator<Map.Entry<String,Method>>() {
- @Override
- public int compare(Map.Entry<String,Method> e1, Map.Entry<String,Method> e2) {
- return e1.getKey().compareTo(e2.getKey());
- }
- };
-
- private void makeSortedMethodList() {
- checkClassAndSuperName();
-
- hasGetHandler = false; // getMethods() may set this to true.
- Map<String,Method> allMethods = getMethods(superClass, interfaces);
- signatureMethods = new ArrayList<Map.Entry<String,Method>>(allMethods.entrySet());
- Collections.sort(signatureMethods, sorter);
- }
-
- private void computeSignature(MethodFilter filter) // throws CannotCompileException
- {
- makeSortedMethodList();
-
- int l = signatureMethods.size();
- int maxBytes = ((l + 7) >> 3);
- signature = new byte[maxBytes];
- for (int idx = 0; idx < l; idx++)
- {
- Method m = signatureMethods.get(idx).getValue();
- int mod = m.getModifiers();
- if (!Modifier.isFinal(mod) && !Modifier.isStatic(mod)
- && isVisible(mod, basename, m) && (filter == null || filter.isHandled(m))) {
- setBit(signature, idx);
- }
- }
- }
-
- private void installSignature(byte[] signature) // throws CannotCompileException
- {
- makeSortedMethodList();
-
- int l = signatureMethods.size();
- int maxBytes = ((l + 7) >> 3);
- if (signature.length != maxBytes) {
- throw new RuntimeException("invalid filter signature length for deserialized proxy class");
- }
-
- this.signature = signature;
- }
-
- private boolean testBit(byte[] signature, int idx) {
- int byteIdx = idx >> 3;
- if (byteIdx > signature.length)
- return false;
- int bitIdx = idx & 0x7;
- int mask = 0x1 << bitIdx;
- int sigByte = signature[byteIdx];
- return ((sigByte & mask) != 0);
- }
-
- private void setBit(byte[] signature, int idx) {
- int byteIdx = idx >> 3;
- if (byteIdx < signature.length) {
- int bitIdx = idx & 0x7;
- int mask = 0x1 << bitIdx;
- int sigByte = signature[byteIdx];
- signature[byteIdx] = (byte)(sigByte | mask);
- }
- }
-
- private static void setInterfaces(ClassFile cf, Class<?>[] interfaces, Class<?> proxyClass) {
- String setterIntf = proxyClass.getName();
- String[] list;
- if (interfaces == null || interfaces.length == 0)
- list = new String[] { setterIntf };
- else {
- list = new String[interfaces.length + 1];
- for (int i = 0; i < interfaces.length; i++)
- list[i] = interfaces[i].getName();
-
- list[interfaces.length] = setterIntf;
- }
-
- cf.setInterfaces(list);
- }
-
- private static void addClassInitializer(ClassFile cf, ConstPool cp,
- String classname, int size, List<Find2MethodsArgs> forwarders)
- throws CannotCompileException
- {
- FieldInfo finfo = new FieldInfo(cp, HOLDER, HOLDER_TYPE);
- finfo.setAccessFlags(AccessFlag.PRIVATE | AccessFlag.STATIC);
- cf.addField(finfo);
- MethodInfo minfo = new MethodInfo(cp, "<clinit>", "()V");
- minfo.setAccessFlags(AccessFlag.STATIC);
- setThrows(minfo, cp, new Class<?>[] { ClassNotFoundException.class });
-
- Bytecode code = new Bytecode(cp, 0, 2);
- code.addIconst(size * 2);
- code.addAnewarray("java.lang.reflect.Method");
- final int varArray = 0;
- code.addAstore(varArray);
-
- // forName() must be called here. Otherwise, the class might be
- // invisible.
- code.addLdc(classname);
- code.addInvokestatic("java.lang.Class",
- "forName", "(Ljava/lang/String;)Ljava/lang/Class;");
- final int varClass = 1;
- code.addAstore(varClass);
-
- for (Find2MethodsArgs args:forwarders)
- callFind2Methods(code, args.methodName, args.delegatorName,
- args.origIndex, args.descriptor, varClass, varArray);
-
- code.addAload(varArray);
- code.addPutstatic(classname, HOLDER, HOLDER_TYPE);
-
- code.addLconst(SERIAL_VERSION_UID_VALUE);
- code.addPutstatic(classname, SERIAL_VERSION_UID_FIELD, SERIAL_VERSION_UID_TYPE);
- code.addOpcode(Bytecode.RETURN);
- minfo.setCodeAttribute(code.toCodeAttribute());
- cf.addMethod(minfo);
- }
-
- /**
- * @param thisMethod might be null.
- */
- private static void callFind2Methods(Bytecode code, String superMethod, String thisMethod,
- int index, String desc, int classVar, int arrayVar) {
- String findClass = RuntimeSupport.class.getName();
- String findDesc
- = "(Ljava/lang/Class;Ljava/lang/String;Ljava/lang/String;ILjava/lang/String;[Ljava/lang/reflect/Method;)V";
-
- code.addAload(classVar);
- code.addLdc(superMethod);
- if (thisMethod == null)
- code.addOpcode(Opcode.ACONST_NULL);
- else
- code.addLdc(thisMethod);
-
- code.addIconst(index);
- code.addLdc(desc);
- code.addAload(arrayVar);
- code.addInvokestatic(findClass, "find2Methods", findDesc);
- }
-
- private static void addSetter(String classname, ClassFile cf, ConstPool cp)
- throws CannotCompileException
- {
- MethodInfo minfo = new MethodInfo(cp, HANDLER_SETTER,
- HANDLER_SETTER_TYPE);
- minfo.setAccessFlags(AccessFlag.PUBLIC);
- Bytecode code = new Bytecode(cp, 2, 2);
- code.addAload(0);
- code.addAload(1);
- code.addPutfield(classname, HANDLER, HANDLER_TYPE);
- code.addOpcode(Bytecode.RETURN);
- minfo.setCodeAttribute(code.toCodeAttribute());
- cf.addMethod(minfo);
- }
-
- private static void addGetter(String classname, ClassFile cf, ConstPool cp)
- throws CannotCompileException
- {
- MethodInfo minfo = new MethodInfo(cp, HANDLER_GETTER,
- HANDLER_GETTER_TYPE);
- minfo.setAccessFlags(AccessFlag.PUBLIC);
- Bytecode code = new Bytecode(cp, 1, 1);
- code.addAload(0);
- code.addGetfield(classname, HANDLER, HANDLER_TYPE);
- code.addOpcode(Bytecode.ARETURN);
- minfo.setCodeAttribute(code.toCodeAttribute());
- cf.addMethod(minfo);
- }
-
- private int overrideMethods(ClassFile cf, ConstPool cp, String className, List<Find2MethodsArgs> forwarders)
- throws CannotCompileException
- {
- String prefix = makeUniqueName("_d", signatureMethods);
- Iterator<Map.Entry<String,Method>> it = signatureMethods.iterator();
- int index = 0;
- while (it.hasNext()) {
- Map.Entry<String,Method> e = it.next();
- if (ClassFile.MAJOR_VERSION < ClassFile.JAVA_5 || !isBridge(e.getValue()))
- if (testBit(signature, index)) {
- override(className, e.getValue(), prefix, index,
- keyToDesc(e.getKey(), e.getValue()), cf, cp, forwarders);
- }
-
- index++;
- }
-
- return index;
- }
-
- private static boolean isBridge(Method m) {
- return m.isBridge();
- }
-
- private void override(String thisClassname, Method meth, String prefix,
- int index, String desc, ClassFile cf, ConstPool cp,
- List<Find2MethodsArgs> forwarders)
- throws CannotCompileException
- {
- Class<?> declClass = meth.getDeclaringClass();
- String delegatorName = prefix + index + meth.getName();
- if (Modifier.isAbstract(meth.getModifiers()))
- delegatorName = null;
- else {
- MethodInfo delegator
- = makeDelegator(meth, desc, cp, declClass, delegatorName);
- // delegator is not a bridge method. See Sec. 15.12.4.5 of JLS 3rd Ed.
- delegator.setAccessFlags(delegator.getAccessFlags() & ~AccessFlag.BRIDGE);
- cf.addMethod(delegator);
- }
-
- MethodInfo forwarder
- = makeForwarder(thisClassname, meth, desc, cp, declClass,
- delegatorName, index, forwarders);
- cf.addMethod(forwarder);
- }
-
- private void makeConstructors(String thisClassName, ClassFile cf,
- ConstPool cp, String classname) throws CannotCompileException
- {
- Constructor<?>[] cons = SecurityActions.getDeclaredConstructors(superClass);
- // legacy: if we are not caching then we need to initialise the default handler
- boolean doHandlerInit = !factoryUseCache;
- for (int i = 0; i < cons.length; i++) {
- Constructor<?> c = cons[i];
- int mod = c.getModifiers();
- if (!Modifier.isFinal(mod) && !Modifier.isPrivate(mod)
- && isVisible(mod, basename, c)) {
- MethodInfo m = makeConstructor(thisClassName, c, cp, superClass, doHandlerInit);
- cf.addMethod(m);
- }
- }
- }
-
- private static String makeUniqueName(String name, List<Map.Entry<String,Method>> sortedMethods) {
- if (makeUniqueName0(name, sortedMethods.iterator()))
- return name;
-
- for (int i = 100; i < 999; i++) {
- String s = name + i;
- if (makeUniqueName0(s, sortedMethods.iterator()))
- return s;
- }
-
- throw new RuntimeException("cannot make a unique method name");
- }
-
- private static boolean makeUniqueName0(String name, Iterator<Map.Entry<String,Method>> it) {
- while (it.hasNext())
- if (it.next().getKey().startsWith(name))
- return false;
- return true;
- }
-
- /**
- * Returns true if the method is visible from the package.
- *
- * @param mod the modifiers of the method.
- */
- private static boolean isVisible(int mod, String from, Member meth) {
- if ((mod & Modifier.PRIVATE) != 0)
- return false;
- else if ((mod & (Modifier.PUBLIC | Modifier.PROTECTED)) != 0)
- return true;
- else {
- String p = getPackageName(from);
- String q = getPackageName(meth.getDeclaringClass().getName());
- if (p == null)
- return q == null;
- return p.equals(q);
- }
- }
-
- private static String getPackageName(String name) {
- int i = name.lastIndexOf('.');
- if (i < 0)
- return null;
- return name.substring(0, i);
- }
-
- /* getMethods() may set hasGetHandler to true.
- */
- private Map<String,Method> getMethods(Class<?> superClass, Class<?>[] interfaceTypes) {
- Map<String,Method> hash = new HashMap<String,Method>();
- Set<Class<?>> set = new HashSet<Class<?>>();
- for (int i = 0; i < interfaceTypes.length; i++)
- getMethods(hash, interfaceTypes[i], set);
-
- getMethods(hash, superClass, set);
- return hash;
- }
-
- private void getMethods(Map<String,Method> hash, Class<?> clazz, Set<Class<?>> visitedClasses) {
- // This both speeds up scanning by avoiding duplicate interfaces and is needed to
- // ensure that superinterfaces are always scanned before subinterfaces.
- if (!visitedClasses.add(clazz))
- return;
-
- Class<?>[] ifs = clazz.getInterfaces();
- for (int i = 0; i < ifs.length; i++)
- getMethods(hash, ifs[i], visitedClasses);
-
- Class<?> parent = clazz.getSuperclass();
- if (parent != null)
- getMethods(hash, parent, visitedClasses);
-
- /* Java 5 or later allows covariant return types.
- * It also allows contra-variant parameter types
- * if a super class is a generics with concrete type arguments
- * such as Foo<String>. So the method-overriding rule is complex.
- */
- Method[] methods = SecurityActions.getDeclaredMethods(clazz);
- for (int i = 0; i < methods.length; i++)
- if (!Modifier.isPrivate(methods[i].getModifiers())) {
- Method m = methods[i];
- String key = m.getName() + ':' + RuntimeSupport.makeDescriptor(m); // see keyToDesc().
- if (key.startsWith(HANDLER_GETTER_KEY))
- hasGetHandler = true;
-
- // JIRA JASSIST-85
- // put the method to the cache, retrieve previous definition (if any)
- Method oldMethod = hash.put(key, m);
-
- // JIRA JASSIST-244
- // ignore a bridge method with the same signature that the overridden one has.
- if (null != oldMethod && isBridge(m)
- && !Modifier.isPublic(oldMethod.getDeclaringClass().getModifiers())
- && !Modifier.isAbstract(oldMethod.getModifiers()) && !isDuplicated(i, methods))
- hash.put(key, oldMethod);
-
- // check if visibility has been reduced
- if (null != oldMethod && Modifier.isPublic(oldMethod.getModifiers())
- && !Modifier.isPublic(m.getModifiers())) {
- // we tried to overwrite a public definition with a non-public definition,
- // use the old definition instead.
- hash.put(key, oldMethod);
- }
- }
- }
-
- private static boolean isDuplicated(int index, Method[] methods) {
- String name = methods[index].getName();
- for (int i = 0; i < methods.length; i++)
- if (i != index)
- if (name.equals(methods[i].getName()) && areParametersSame(methods[index], methods[i]))
- return true;
-
- return false;
- }
-
- private static boolean areParametersSame(Method method, Method targetMethod) {
- Class<?>[] methodTypes = method.getParameterTypes();
- Class<?>[] targetMethodTypes = targetMethod.getParameterTypes();
- if (methodTypes.length == targetMethodTypes.length) {
- for (int i = 0; i< methodTypes.length; i++) {
- if (methodTypes[i].getName().equals(targetMethodTypes[i].getName())) {
- continue;
- } else {
- return false;
- }
- }
- return true;
- }
- return false;
- }
-
- private static final String HANDLER_GETTER_KEY
- = HANDLER_GETTER + ":()";
-
- private static String keyToDesc(String key, Method m) {
- return key.substring(key.indexOf(':') + 1);
- }
-
- private static MethodInfo makeConstructor(String thisClassName, Constructor<?> cons,
- ConstPool cp, Class<?> superClass, boolean doHandlerInit) {
- String desc = RuntimeSupport.makeDescriptor(cons.getParameterTypes(),
- Void.TYPE);
- MethodInfo minfo = new MethodInfo(cp, "<init>", desc);
- minfo.setAccessFlags(Modifier.PUBLIC); // cons.getModifiers() & ~Modifier.NATIVE
- setThrows(minfo, cp, cons.getExceptionTypes());
- Bytecode code = new Bytecode(cp, 0, 0);
-
- // legacy: if we are not using caching then we initialise the instance's handler
- // from the class's static default interceptor and skip the next few instructions if
- // it is non-null
- if (doHandlerInit) {
- code.addAload(0);
- code.addGetstatic(thisClassName, DEFAULT_INTERCEPTOR, HANDLER_TYPE);
- code.addPutfield(thisClassName, HANDLER, HANDLER_TYPE);
- code.addGetstatic(thisClassName, DEFAULT_INTERCEPTOR, HANDLER_TYPE);
- code.addOpcode(Opcode.IFNONNULL);
- code.addIndex(10);
- }
- // if caching is enabled then we don't have a handler to initialise so this else branch will install
- // the handler located in the static field of class RuntimeSupport.
- code.addAload(0);
- code.addGetstatic(NULL_INTERCEPTOR_HOLDER, DEFAULT_INTERCEPTOR, HANDLER_TYPE);
- code.addPutfield(thisClassName, HANDLER, HANDLER_TYPE);
- int pc = code.currentPc();
-
- code.addAload(0);
- int s = addLoadParameters(code, cons.getParameterTypes(), 1);
- code.addInvokespecial(superClass.getName(), "<init>", desc);
- code.addOpcode(Opcode.RETURN);
- code.setMaxLocals(s + 1);
- CodeAttribute ca = code.toCodeAttribute();
- minfo.setCodeAttribute(ca);
-
- StackMapTable.Writer writer = new StackMapTable.Writer(32);
- writer.sameFrame(pc);
- ca.setAttribute(writer.toStackMapTable(cp));
- return minfo;
- }
-
- private MethodInfo makeDelegator(Method meth, String desc,
- ConstPool cp, Class<?> declClass, String delegatorName) {
- MethodInfo delegator = new MethodInfo(cp, delegatorName, desc);
- delegator.setAccessFlags(Modifier.FINAL | Modifier.PUBLIC
- | (meth.getModifiers() & ~(Modifier.PRIVATE
- | Modifier.PROTECTED
- | Modifier.ABSTRACT
- | Modifier.NATIVE
- | Modifier.SYNCHRONIZED)));
- setThrows(delegator, cp, meth);
- Bytecode code = new Bytecode(cp, 0, 0);
- code.addAload(0);
- int s = addLoadParameters(code, meth.getParameterTypes(), 1);
- Class<?> targetClass = invokespecialTarget(declClass);
- code.addInvokespecial(targetClass.isInterface(), cp.addClassInfo(targetClass.getName()),
- meth.getName(), desc);
- addReturn(code, meth.getReturnType());
- code.setMaxLocals(++s);
- delegator.setCodeAttribute(code.toCodeAttribute());
- return delegator;
- }
-
- /* Suppose that the receiver type is S, the invoked method
- * is declared in T, and U is the immediate super class of S
- * (or its interface). If S <: U <: T (S <: T reads "S extends T"),
- * the target type of invokespecial has to be not T but U.
- */
- private Class<?> invokespecialTarget(Class<?> declClass) {
- if (declClass.isInterface())
- for (Class<?> i: interfaces)
- if (declClass.isAssignableFrom(i))
- return i;
-
- return superClass;
- }
-
- /**
- * @param delegatorName null if the original method is abstract.
- */
- private static MethodInfo makeForwarder(String thisClassName,
- Method meth, String desc, ConstPool cp,
- Class<?> declClass, String delegatorName, int index,
- List<Find2MethodsArgs> forwarders) {
- MethodInfo forwarder = new MethodInfo(cp, meth.getName(), desc);
- forwarder.setAccessFlags(Modifier.FINAL
- | (meth.getModifiers() & ~(Modifier.ABSTRACT
- | Modifier.NATIVE
- | Modifier.SYNCHRONIZED)));
- setThrows(forwarder, cp, meth);
- int args = Descriptor.paramSize(desc);
- Bytecode code = new Bytecode(cp, 0, args + 2);
- /*
- * static {
- * methods[index * 2]
- * = RuntimeSupport.findSuperMethod(this, <overridden name>, <desc>);
- * methods[index * 2 + 1]
- * = RuntimeSupport.findMethod(this, <delegator name>, <desc>);
- * or = null // the original method is abstract.
- * }
- * :
- * return ($r)handler.invoke(this, methods[index * 2],
- * methods[index * 2 + 1], $args);
- */
- int origIndex = index * 2;
- int delIndex = index * 2 + 1;
- int arrayVar = args + 1;
- code.addGetstatic(thisClassName, HOLDER, HOLDER_TYPE);
- code.addAstore(arrayVar);
-
- forwarders.add(new Find2MethodsArgs(meth.getName(), delegatorName, desc, origIndex));
-
- code.addAload(0);
- code.addGetfield(thisClassName, HANDLER, HANDLER_TYPE);
- code.addAload(0);
-
- code.addAload(arrayVar);
- code.addIconst(origIndex);
- code.addOpcode(Opcode.AALOAD);
-
- code.addAload(arrayVar);
- code.addIconst(delIndex);
- code.addOpcode(Opcode.AALOAD);
-
- makeParameterList(code, meth.getParameterTypes());
- code.addInvokeinterface(MethodHandler.class.getName(), "invoke",
- "(Ljava/lang/Object;Ljava/lang/reflect/Method;Ljava/lang/reflect/Method;[Ljava/lang/Object;)Ljava/lang/Object;",
- 5);
- Class<?> retType = meth.getReturnType();
- addUnwrapper(code, retType);
- addReturn(code, retType);
-
- CodeAttribute ca = code.toCodeAttribute();
- forwarder.setCodeAttribute(ca);
- return forwarder;
- }
-
- static class Find2MethodsArgs {
- String methodName, delegatorName, descriptor;
- int origIndex;
-
- Find2MethodsArgs(String mname, String dname, String desc, int index) {
- methodName = mname;
- delegatorName = dname;
- descriptor = desc;
- origIndex = index;
- }
- }
-
- private static void setThrows(MethodInfo minfo, ConstPool cp, Method orig) {
- Class<?>[] exceptions = orig.getExceptionTypes();
- setThrows(minfo, cp, exceptions);
- }
-
- private static void setThrows(MethodInfo minfo, ConstPool cp,
- Class<?>[] exceptions) {
- if (exceptions.length == 0)
- return;
-
- String[] list = new String[exceptions.length];
- for (int i = 0; i < exceptions.length; i++)
- list[i] = exceptions[i].getName();
-
- ExceptionsAttribute ea = new ExceptionsAttribute(cp);
- ea.setExceptions(list);
- minfo.setExceptionsAttribute(ea);
- }
-
- private static int addLoadParameters(Bytecode code, Class<?>[] params,
- int offset) {
- int stacksize = 0;
- int n = params.length;
- for (int i = 0; i < n; ++i)
- stacksize += addLoad(code, stacksize + offset, params[i]);
-
- return stacksize;
- }
-
- private static int addLoad(Bytecode code, int n, Class<?> type) {
- if (type.isPrimitive()) {
- if (type == Long.TYPE) {
- code.addLload(n);
- return 2;
- }
- else if (type == Float.TYPE)
- code.addFload(n);
- else if (type == Double.TYPE) {
- code.addDload(n);
- return 2;
- }
- else
- code.addIload(n);
- }
- else
- code.addAload(n);
-
- return 1;
- }
-
- private static int addReturn(Bytecode code, Class<?> type) {
- if (type.isPrimitive()) {
- if (type == Long.TYPE) {
- code.addOpcode(Opcode.LRETURN);
- return 2;
- }
- else if (type == Float.TYPE)
- code.addOpcode(Opcode.FRETURN);
- else if (type == Double.TYPE) {
- code.addOpcode(Opcode.DRETURN);
- return 2;
- }
- else if (type == Void.TYPE) {
- code.addOpcode(Opcode.RETURN);
- return 0;
- }
- else
- code.addOpcode(Opcode.IRETURN);
- }
- else
- code.addOpcode(Opcode.ARETURN);
-
- return 1;
- }
-
- private static void makeParameterList(Bytecode code, Class<?>[] params) {
- int regno = 1;
- int n = params.length;
- code.addIconst(n);
- code.addAnewarray("java/lang/Object");
- for (int i = 0; i < n; i++) {
- code.addOpcode(Opcode.DUP);
- code.addIconst(i);
- Class<?> type = params[i];
- if (type.isPrimitive())
- regno = makeWrapper(code, type, regno);
- else {
- code.addAload(regno);
- regno++;
- }
-
- code.addOpcode(Opcode.AASTORE);
- }
- }
-
- private static int makeWrapper(Bytecode code, Class<?> type, int regno) {
- int index = FactoryHelper.typeIndex(type);
- String wrapper = FactoryHelper.wrapperTypes[index];
- code.addNew(wrapper);
- code.addOpcode(Opcode.DUP);
- addLoad(code, regno, type);
- code.addInvokespecial(wrapper, "<init>",
- FactoryHelper.wrapperDesc[index]);
- return regno + FactoryHelper.dataSize[index];
- }
-
- private static void addUnwrapper(Bytecode code, Class<?> type) {
- if (type.isPrimitive()) {
- if (type == Void.TYPE)
- code.addOpcode(Opcode.POP);
- else {
- int index = FactoryHelper.typeIndex(type);
- String wrapper = FactoryHelper.wrapperTypes[index];
- code.addCheckcast(wrapper);
- code.addInvokevirtual(wrapper,
- FactoryHelper.unwarpMethods[index],
- FactoryHelper.unwrapDesc[index]);
- }
- }
- else
- code.addCheckcast(type.getName());
- }
-
- private static MethodInfo makeWriteReplace(ConstPool cp) {
- MethodInfo minfo = new MethodInfo(cp, "writeReplace", "()Ljava/lang/Object;");
- String[] list = new String[1];
- list[0] = "java.io.ObjectStreamException";
- ExceptionsAttribute ea = new ExceptionsAttribute(cp);
- ea.setExceptions(list);
- minfo.setExceptionsAttribute(ea);
- Bytecode code = new Bytecode(cp, 0, 1);
- code.addAload(0);
- code.addInvokestatic("javassist.util.proxy.RuntimeSupport",
- "makeSerializedProxy",
- "(Ljava/lang/Object;)Ljavassist/util/proxy/SerializedProxy;");
- code.addOpcode(Opcode.ARETURN);
- minfo.setCodeAttribute(code.toCodeAttribute());
- return minfo;
- }
- }
|