/*
* Copyright (c) 2003-2007 The Visigoth Software Society. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowledgement:
* "This product includes software developed by the
* Visigoth Software Society (http://www.visigoths.org/)."
* Alternately, this acknowledgement may appear in the software itself,
* if and wherever such third-party acknowledgements normally appear.
*
* 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the
* project contributors may be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact [email protected].
*
* 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
* nor may "FreeMarker" or "Visigoth" appear in their names
* without prior written permission of the Visigoth Software Society.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Visigoth Software Society. For more
* information on the Visigoth Software Society, please see
* http://www.visigoths.org/
*/
package freemarker.ext.beans;
import java.lang.reflect.Constructor;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import freemarker.template.utility.UndeclaredThrowableException;
class MethodUtilities
{
static final Class OBJECT_CLASS = Object.class;
private static final Method METHOD_IS_VARARGS = getIsVarArgsMethod(Method.class);
private static final Method CONSTRUCTOR_IS_VARARGS = getIsVarArgsMethod(Constructor.class);
static Class getMostSpecificCommonType(Class c1, Class c2) {
if(c1 == c2) {
return c1;
}
if(c2.isPrimitive()) {
if(c2 == Byte.TYPE) c2 = Byte.class;
else if(c2 == Short.TYPE) c2 = Short.class;
else if(c2 == Character.TYPE) c2 = Character.class;
else if(c2 == Integer.TYPE) c2 = Integer.class;
else if(c2 == Float.TYPE) c2 = Float.class;
else if(c2 == Long.TYPE) c2 = Long.class;
else if(c2 == Double.TYPE) c2 = Double.class;
}
Set a1 = getAssignables(c1, c2);
Set a2 = getAssignables(c2, c1);
a1.retainAll(a2);
if(a1.isEmpty()) {
// Can happen when at least one of the arguments is an interface, as
// they don't have Object at the root of their hierarchy
return Object.class;
}
// Gather maximally specific elements. Yes, there can be more than one
// thank to interfaces. I.e., if you call this method for String.class
// and Number.class, you'll have Comparable, Serializable, and Object as
// maximal elements.
List max = new ArrayList();
outer: for (Iterator it = a1.iterator(); it.hasNext();) {
Class clazz = (Class)it.next();
for (Iterator maxiter = max.iterator(); maxiter.hasNext();) {
Class maxClazz = (Class)maxiter.next();
if(isMoreSpecific(maxClazz, clazz)) {
// It can't be maximal, if there's already a more specific
// maximal than it.
continue outer;
}
if(isMoreSpecific(clazz, maxClazz)) {
// If it's more specific than a currently maximal element,
// that currently maximal is no longer a maximal.
maxiter.remove();
}
}
// If we get here, no current maximal is more specific than the
// current class, so it is considered maximal as well
max.add(clazz);
}
if(max.size() > 1) {
return OBJECT_CLASS;
}
return (Class)max.get(0);
}
/**
* Determines whether a type represented by a class object is
* convertible to another type represented by a class object using a
* method invocation conversion, without matching object and primitive
* types. This method is used to determine the more specific type when
* comparing signatures of methods.
* @return true if either formal type is assignable from actual type,
* or formal and actual are both primitive types and actual can be
* subject to widening conversion to formal.
*/
static boolean isMoreSpecific(Class specific, Class generic) {
// Check for identity or widening reference conversion
if(generic.isAssignableFrom(specific)) {
return true;
}
// Check for widening primitive conversion.
if(generic.isPrimitive()) {
if(generic == Short.TYPE && (specific == Byte.TYPE)) {
return true;
}
if(generic == Integer.TYPE &&
(specific == Short.TYPE || specific == Byte.TYPE)) {
return true;
}
if(generic == Long.TYPE &&
(specific == Integer.TYPE || specific == Short.TYPE ||
specific == Byte.TYPE)) {
return true;
}
if(generic == Float.TYPE &&
(specific == Long.TYPE || specific == Integer.TYPE ||
specific == Short.TYPE || specific == Byte.TYPE)) {
return true;
}
if(generic == Double.TYPE &&
(specific == Float.TYPE || specific == Long.TYPE ||
specific == Integer.TYPE || specific == Short.TYPE ||
specific == Byte.TYPE)) {
return true;
}
}
return false;
}
private static Set getAssignables(Class c1, Class c2) {
Set s = new HashSet();
collectAssignables(c1, c2, s);
return s;
}
private static void collectAssignables(Class c1, Class c2, Set s) {
if(c1.isAssignableFrom(c2)) {
s.add(c1);
}
Class sc = c1.getSuperclass();
if(sc != null) {
collectAssignables(sc, c2, s);
}
Class[] itf = c1.getInterfaces();
for(int i = 0; i < itf.length; ++i) {
collectAssignables(itf[i], c2, s);
}
}
static Class[] getParameterTypes(Member member) {
if(member instanceof Method) {
return ((Method)member).getParameterTypes();
}
if(member instanceof Constructor) {
return ((Constructor)member).getParameterTypes();
}
throw new RuntimeException();
}
static boolean isVarArgs(Member member) {
if(member instanceof Method) {
return isVarArgs(member, METHOD_IS_VARARGS);
}
if(member instanceof Constructor) {
return isVarArgs(member, CONSTRUCTOR_IS_VARARGS);
}
throw new RuntimeException();
}
private static boolean isVarArgs(Member member, Method isVarArgsMethod) {
if(isVarArgsMethod == null) {
return false;
}
try {
return ((Boolean)isVarArgsMethod.invoke(member, (Object[]) null)).booleanValue();
}
catch(RuntimeException e) {
throw e;
}
catch(Exception e) {
throw new UndeclaredThrowableException(e);
}
}
private static Method getIsVarArgsMethod(Class memberClass) {
try {
return memberClass.getMethod("isVarArgs", (Class[]) null);
}
catch(NoSuchMethodException e) {
return null; // pre 1.5 JRE
}
}
}
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