/*
* Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.reflect.misc;
import java.security.AllPermission;
import java.security.AccessController;
import java.security.PermissionCollection;
import java.security.SecureClassLoader;
import java.security.PrivilegedExceptionAction;
import java.security.CodeSource;
import java.io.InputStream;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.net.URL;
import java.net.URLConnection;
import java.lang.reflect.Method;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Modifier;
import java.util.HashMap;
import java.util.Map;
import sun.misc.IOUtils;
class Trampoline {
static {
if (Trampoline.class.getClassLoader() == null) {
throw new Error(
"Trampoline must not be defined by the bootstrap classloader");
}
}
private static void ensureInvocableMethod(Method m)
throws InvocationTargetException
{
Class<?> clazz = m.getDeclaringClass();
if (clazz.equals(AccessController.class) ||
clazz.equals(Method.class) ||
clazz.getName().startsWith("java.lang.invoke."))
throw new InvocationTargetException(
new UnsupportedOperationException("invocation not supported"));
}
private static Object invoke(Method m, Object obj, Object[] params)
throws InvocationTargetException, IllegalAccessException
{
ensureInvocableMethod(m);
return m.invoke(obj, params);
}
}
/*
* Create a trampoline class.
*/
public final class MethodUtil extends SecureClassLoader {
private static final String MISC_PKG = "sun.reflect.misc.";
private static final String TRAMPOLINE = MISC_PKG + "Trampoline";
private static final Method bounce = getTrampoline();
private MethodUtil() {
super();
}
public static Method getMethod(Class<?> cls, String name, Class<?>[] args)
throws NoSuchMethodException {
ReflectUtil.checkPackageAccess(cls);
return cls.getMethod(name, args);
}
public static Method[] getMethods(Class<?> cls) {
ReflectUtil.checkPackageAccess(cls);
return cls.getMethods();
}
/*
* Discover the public methods on public classes
* and interfaces accessible to any caller by calling
* Class.getMethods() and walking towards Object until
* we're done.
*/
public static Method[] getPublicMethods(Class<?> cls) {
// compatibility for update release
if (System.getSecurityManager() == null) {
return cls.getMethods();
}
Map<Signature, Method> sigs = new HashMap<Signature, Method>();
while (cls != null) {
boolean done = getInternalPublicMethods(cls, sigs);
if (done) {
break;
}
getInterfaceMethods(cls, sigs);
cls = cls.getSuperclass();
}
return sigs.values().toArray(new Method[sigs.size()]);
}
/*
* Process the immediate interfaces of this class or interface.
*/
private static void getInterfaceMethods(Class<?> cls,
Map<Signature, Method> sigs) {
Class<?>[] intfs = cls.getInterfaces();
for (int i=0; i < intfs.length; i++) {
Class<?> intf = intfs[i];
boolean done = getInternalPublicMethods(intf, sigs);
if (!done) {
getInterfaceMethods(intf, sigs);
}
}
}
/*
*
* Process the methods in this class or interface
*/
private static boolean getInternalPublicMethods(Class<?> cls,
Map<Signature, Method> sigs) {
Method[] methods = null;
try {
/*
* This class or interface is non-public so we
* can't use any of it's methods. Go back and
* try again with a superclass or superinterface.
*/
if (!Modifier.isPublic(cls.getModifiers())) {
return false;
}
if (!ReflectUtil.isPackageAccessible(cls)) {
return false;
}
methods = cls.getMethods();
} catch (SecurityException se) {
return false;
}
/*
* Check for inherited methods with non-public
* declaring classes. They might override and hide
* methods from their superclasses or
* superinterfaces.
*/
boolean done = true;
for (int i=0; i < methods.length; i++) {
Class<?> dc = methods[i].getDeclaringClass();
if (!Modifier.isPublic(dc.getModifiers())) {
done = false;
break;
}
}
if (done) {
/*
* We're done. Spray all the methods into
* the list and then we're out of here.
*/
for (int i=0; i < methods.length; i++) {
addMethod(sigs, methods[i]);
}
} else {
/*
* Simulate cls.getDeclaredMethods() by
* stripping away inherited methods.
*/
for (int i=0; i < methods.length; i++) {
Class<?> dc = methods[i].getDeclaringClass();
if (cls.equals(dc)) {
addMethod(sigs, methods[i]);
}
}
}
return done;
}
private static void addMethod(Map<Signature, Method> sigs, Method method) {
Signature signature = new Signature(method);
if (!sigs.containsKey(signature)) {
sigs.put(signature, method);
} else if (!method.getDeclaringClass().isInterface()){
/*
* Superclasses beat interfaces.
*/
Method old = sigs.get(signature);
if (old.getDeclaringClass().isInterface()) {
sigs.put(signature, method);
}
}
}
/**
* A class that represents the unique elements of a method that will be a
* key in the method cache.
*/
private static class Signature {
private String methodName;
private Class<?>[] argClasses;
private volatile int hashCode = 0;
Signature(Method m) {
this.methodName = m.getName();
this.argClasses = m.getParameterTypes();
}
public boolean equals(Object o2) {
if (this == o2) {
return true;
}
Signature that = (Signature)o2;
if (!(methodName.equals(that.methodName))) {
return false;
}
if (argClasses.length != that.argClasses.length) {
return false;
}
for (int i = 0; i < argClasses.length; i++) {
if (!(argClasses[i] == that.argClasses[i])) {
return false;
}
}
return true;
}
/**
* Hash code computed using algorithm suggested in
* Effective Java, Item 8.
*/
public int hashCode() {
if (hashCode == 0) {
int result = 17;
result = 37 * result + methodName.hashCode();
if (argClasses != null) {
for (int i = 0; i < argClasses.length; i++) {
result = 37 * result + ((argClasses[i] == null) ? 0 :
argClasses[i].hashCode());
}
}
hashCode = result;
}
return hashCode;
}
}
/*
* Bounce through the trampoline.
*/
public static Object invoke(Method m, Object obj, Object[] params)
throws InvocationTargetException, IllegalAccessException {
try {
return bounce.invoke(null, new Object[] {m, obj, params});
} catch (InvocationTargetException ie) {
Throwable t = ie.getCause();
if (t instanceof InvocationTargetException) {
throw (InvocationTargetException)t;
} else if (t instanceof IllegalAccessException) {
throw (IllegalAccessException)t;
} else if (t instanceof RuntimeException) {
throw (RuntimeException)t;
} else if (t instanceof Error) {
throw (Error)t;
} else {
throw new Error("Unexpected invocation error", t);
}
} catch (IllegalAccessException iae) {
// this can't happen
throw new Error("Unexpected invocation error", iae);
}
}
private static Method getTrampoline() {
try {
return AccessController.doPrivileged(
new PrivilegedExceptionAction<Method>() {
public Method run() throws Exception {
Class<?> t = getTrampolineClass();
Class<?>[] types = {
Method.class, Object.class, Object[].class
};
Method b = t.getDeclaredMethod("invoke", types);
b.setAccessible(true);
return b;
}
});
} catch (Exception e) {
throw new InternalError("bouncer cannot be found", e);
}
}
protected synchronized Class<?> loadClass(String name, boolean resolve)
throws ClassNotFoundException
{
// First, check if the class has already been loaded
ReflectUtil.checkPackageAccess(name);
Class<?> c = findLoadedClass(name);
if (c == null) {
try {
c = findClass(name);
} catch (ClassNotFoundException e) {
// Fall through ...
}
if (c == null) {
c = getParent().loadClass(name);
}
}
if (resolve) {
resolveClass(c);
}
return c;
}
protected Class<?> findClass(final String name)
throws ClassNotFoundException
{
if (!name.startsWith(MISC_PKG)) {
throw new ClassNotFoundException(name);
}
String path = name.replace('.', '/').concat(".class");
URL res = getResource(path);
if (res != null) {
try {
return defineClass(name, res);
} catch (IOException e) {
throw new ClassNotFoundException(name, e);
}
} else {
throw new ClassNotFoundException(name);
}
}
/*
* Define the proxy classes
*/
private Class<?> defineClass(String name, URL url) throws IOException {
byte[] b = getBytes(url);
CodeSource cs = new CodeSource(null, (java.security.cert.Certificate[])null);
if (!name.equals(TRAMPOLINE)) {
throw new IOException("MethodUtil: bad name " + name);
}
return defineClass(name, b, 0, b.length, cs);
}
/*
* Returns the contents of the specified URL as an array of bytes.
*/
private static byte[] getBytes(URL url) throws IOException {
URLConnection uc = url.openConnection();
if (uc instanceof java.net.HttpURLConnection) {
java.net.HttpURLConnection huc = (java.net.HttpURLConnection) uc;
int code = huc.getResponseCode();
if (code >= java.net.HttpURLConnection.HTTP_BAD_REQUEST) {
throw new IOException("open HTTP connection failed.");
}
}
int len = uc.getContentLength();
InputStream in = new BufferedInputStream(uc.getInputStream());
byte[] b;
try {
b = IOUtils.readFully(in, len, true);
} finally {
in.close();
}
return b;
}
protected PermissionCollection getPermissions(CodeSource codesource)
{
PermissionCollection perms = super.getPermissions(codesource);
perms.add(new AllPermission());
return perms;
}
private static Class<?> getTrampolineClass() {
try {
return Class.forName(TRAMPOLINE, true, new MethodUtil());
} catch (ClassNotFoundException e) {
}
return null;
}
}
