/*******************************************************************************
* Copyright (c) 2014, 2015 Oracle and/or its affiliates. All rights reserved.
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Marcel Valovy - 2.6 - initial implementation
******************************************************************************/
package org.eclipse.persistence.jaxb;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import static java.security.AccessController.doPrivileged;
import static org.eclipse.persistence.internal.security.PrivilegedAccessHelper.shouldUsePrivilegedAccess;
/**
* Utility class for handling reflection calls and using caller sensitive actions.
*
* - Singleton lazy-loaded actions honoring Initialization On Demand Holder idiom.
* - Lazy-loaded inner classes and inner interfaces. Only loaded if security is enabled.
*
* @author Marcel Valovy - marcel.valovy@oracle.com
* @since 2.6
*/
final class ReflectionUtils {
/**
* Non-instantiable utility class. Reflection instantiation permitted.
*/
private ReflectionUtils() {
}
/**
* Retrieves class object.
* <p>
* If security is enabled, makes {@linkplain java.security.AccessController#doPrivileged(PrivilegedAction)
* privileged calls}.
*
* @param clazz name of class to be retrieved
* @return class object
* @see Class#forName(String)
*/
static Class<?> forName(String clazz) throws ClassNotFoundException {
try {
return shouldUsePrivilegedAccess()
? doPrivileged(ForNameIODH.PREDICATE_EXCEPTION_ACTION.with(clazz))
: forNameInternal(clazz);
} catch (PrivilegedActionException e) {
throw (ClassNotFoundException) e.getException();
}
}
/**
* Retrieves declared fields.
* <p>
* If security is enabled, makes {@linkplain java.security.AccessController#doPrivileged(PrivilegedAction)
* privileged calls}.
*
* @param clazz fields of that class will be returned
* @return array of declared fields
* @see Class#getDeclaredFields()
*/
static Field[] getDeclaredFields(Class<?> clazz) {
return shouldUsePrivilegedAccess()
? doPrivileged(DeclaredFieldsIODH.PREDICATE_ACTION.with(clazz))
: getDeclaredFieldsInternal(clazz);
}
/**
* Retrieves declared constructors.
*
* If security is enabled, makes {@linkplain java.security.AccessController#doPrivileged(PrivilegedAction)
* privileged calls}.
*
* @param clazz class that will be scanned
* @return declared constructors
* @see Class#getDeclaredConstructors()
*/
static Constructor<?>[] getDeclaredConstructors(Class<?> clazz) {
return shouldUsePrivilegedAccess()
? doPrivileged(DeclaredConstructorsIODH.PREDICATE_ACTION.with(clazz))
: getDeclaredConstructorsInternal(clazz);
}
/**
* Retrieves declared methods.
*
* If security is enabled, makes {@linkplain java.security.AccessController#doPrivileged(PrivilegedAction)
* privileged calls}.
*
* @param clazz class that will be scanned
* @return declared methods
* @see Class#getDeclaredMethods()
*/
static Method[] getDeclaredMethods(Class<?> clazz) {
return shouldUsePrivilegedAccess()
? doPrivileged(DeclaredMethodsIODH.PREDICATE_ACTION.with(clazz))
: getDeclaredMethodsInternal(clazz);
}
/**
* Retrieves declared method.
*
* If security is enabled, makes {@linkplain java.security.AccessController#doPrivileged(PrivilegedAction)
* privileged calls}.
*
* @param clazz class that will be scanned
* @param name name of the method to be retrieved
* @param parameterTypes parameter types of the method to be retrieved
* @return declared method
* @throws NoSuchMethodException if method was not found
* @see Class#getDeclaredMethod(String, Class...)
*/
static Method getDeclaredMethod(Class<?> clazz, String name, Class<?>... parameterTypes) throws
NoSuchMethodException {
try {
return shouldUsePrivilegedAccess()
? doPrivileged(DeclaredMethodIODH.PREDICATE_EXCEPTION_ACTION.with(clazz).with(name).with(parameterTypes))
: getDeclaredMethodInternal(clazz, name, parameterTypes);
} catch (PrivilegedActionException e) {
throw (NoSuchMethodException) e.getException();
}
}
/* Internal Methods */
/**
* INTERNAL:
*/
private static Class<?> forNameInternal(String clazz) throws ClassNotFoundException {
return Class.forName(clazz);
}
/**
* INTERNAL:
*/
private static Field[] getDeclaredFieldsInternal(Class<?> clazz) {
return clazz.getDeclaredFields();
}
/**
* INTERNAL:
*/
private static Method[] getDeclaredMethodsInternal(Class<?> clazz) {
return clazz.getDeclaredMethods();
}
/**
* INTERNAL:
*/
private static Constructor<?>[] getDeclaredConstructorsInternal(Class<?> clazz) {
return clazz.getDeclaredConstructors();
}
/**
* INTERNAL:
*/
private static Method getDeclaredMethodInternal(Class<?> clazz, String name, Class<?>... parameterTypes) throws
NoSuchMethodException {
return clazz.getDeclaredMethod(name, parameterTypes);
}
/* Initialization on Demand Holders */
/**
* IODH for enhanced forName privileged action with exception using predicates.
*/
private static final class ForNameIODH {
/**
* Enhanced {@link PrivilegedExceptionAction} using predicates.
* - Singleton.
* - Throws {@link java.lang.ClassNotFoundException}.
*/
private static final PredicateWithException<Class<?>> PREDICATE_EXCEPTION_ACTION = new
PredicateWithException<Class<?>>() {
/* Predicates */
private String clazz;
@Override
public PredicateWithException<Class<?>> with(String with) {
this.clazz = with;
return this;
}
@Override
public PredicateWithException<Class<?>> with(Class<?> with) {
throw new UnsupportedOperationException();
}
@Override
public PredicateWithException<Class<?>> with(Class<?>[] with) {
throw new UnsupportedOperationException();
}
@Override
public Class<?> run() throws NoSuchMethodException, ClassNotFoundException {
return forNameInternal(clazz);
}
};
}
/**
* IODH for enhanced getDeclaredFields privileged action using predicates.
*/
private static final class DeclaredFieldsIODH {
/**
* Enhanced {@link java.security.PrivilegedAction} using predicates.
* - Singleton.
*/
private static final Predicate<Field[]> PREDICATE_ACTION = new Predicate<Field[]>() {
/* Predicates */
private Class<?> clazz;
@Override
public Field[] run() {
return getDeclaredFieldsInternal(clazz);
}
@Override
public Predicate<Field[]> with(Class<?> clazz) {
this.clazz = clazz;
return this;
}
};
}
/**
* IODH for getDeclaredMethods privileged action using predicates.
*/
private static final class DeclaredMethodsIODH {
/**
* Enhanced {@link PrivilegedAction} using predicates.
* - Singleton.
*/
private static final Predicate<Method[]> PREDICATE_ACTION = new
Predicate<Method[]>() {
/* Predicates */
private Class<?> clazz;
@Override
public Predicate<Method[]> with(Class<?> with) {
this.clazz = with;
return this;
}
@Override
public Method[] run() {
return getDeclaredMethodsInternal(clazz);
}
};
}
/**
* IODH for getDeclaredConstructors privileged action using predicates.
*/
private static final class DeclaredConstructorsIODH {
/**
* Enhanced {@link java.security.PrivilegedAction} using predicates.
* - Singleton.
*/
private static final Predicate<Constructor<?>[]> PREDICATE_ACTION = new
Predicate<Constructor<?>[]>() {
/* Predicates */
private Class<?> clazz;
@Override
public Predicate<Constructor<?>[]> with(Class<?> with) {
this.clazz = with;
return this;
}
@Override
public Constructor<?>[] run() {
return getDeclaredConstructorsInternal(clazz);
}
};
}
/**
* IODH for getMethod predicate wrapped privileged exception action.
*/
private static final class DeclaredMethodIODH {
/**
* Enhanced {@link PrivilegedExceptionAction} using predicates.
* - Singleton.
* - Throws {@link NoSuchMethodException}.
*/
private static final PredicateWithException<Method> PREDICATE_EXCEPTION_ACTION = new
PredicateWithException<Method>() {
/* Predicates */
private Class<?> clazz;
private String name;
private Class<?>[] parameterTypes;
@Override
public PredicateWithException<Method> with(Class<?> with) {
this.clazz = with;
return this;
}
@Override
public PredicateWithException<Method> with(String with) {
this.name = with;
return this;
}
@Override
public PredicateWithException<Method> with(Class<?>[] with) {
this.parameterTypes = with;
return this;
}
@Override
public Method run() throws NoSuchMethodException {
return getDeclaredMethodInternal(clazz, name, parameterTypes);
}
};
}
/* Inner Interfaces */
/**
* Predicate-providing wrapper for {@link PrivilegedAction}.
*
* @param <T> return type of {@linkplain PrivilegedAction#run() computation}
*/
private interface Predicate<T> extends PrivilegedAction<T> {
/**
* Assigns a predicate to the underlying privileged action.
* Any previous predicate of the same type will be overwritten.
*
* @param with predicate
* @return {@code this}
*/
Predicate<T> with(Class<?> with);
}
/**
* Predicate-providing wrapper for {@link PrivilegedExceptionAction}.
*
* @param <T> return type of {@linkplain PrivilegedExceptionAction#run() computation}
*/
private interface PredicateWithException<T> extends PrivilegedExceptionAction<T> {
/**
* Assigns a predicate to the underlying privileged exception action.
* Any previous predicate of the same type will be overwritten.
*
* @param with predicate
* @return {@code this}
*/
PredicateWithException<T> with(Class<?> with);
/**
* Assigns a predicate to the underlying privileged exception action.
* Any previous predicate of the same type will be overwritten.
*
* @param with predicate
* @return {@code this}
*/
PredicateWithException<T> with(String with);
/**
* Assigns a predicate to the underlying privileged exception action.
* Any previous predicate of the same type will be overwritten.
*
* @param with predicate
* @return {@code this}
*/
PredicateWithException<T> with(Class<?>[] with);
}
}