/*
* [The "BSD license"]
* Copyright (c) 2011 Terence Parr
* 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 name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 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 AUTHOR 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.
*/
package org.stringtemplate.v4.misc;
import org.stringtemplate.v4.Interpreter;
import org.stringtemplate.v4.ModelAdaptor;
import org.stringtemplate.v4.ST;
import java.lang.reflect.Field;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;
public class ObjectModelAdaptor implements ModelAdaptor {
protected static final Member INVALID_MEMBER;
static {
Member invalidMember;
try {
invalidMember = ObjectModelAdaptor.class.getDeclaredField("INVALID_MEMBER");
} catch (NoSuchFieldException ex) {
invalidMember = null;
} catch (SecurityException ex) {
invalidMember = null;
}
INVALID_MEMBER = invalidMember;
}
protected static final Map<Class<?>, Map<String, Member>> membersCache =
new HashMap<Class<?>, Map<String, Member>>();
@Override
public synchronized Object getProperty(Interpreter interp, ST self, Object o, Object property, String propertyName)
throws STNoSuchPropertyException
{
if (o == null) {
throw new NullPointerException("o");
}
Class<?> c = o.getClass();
if ( property==null ) {
return throwNoSuchProperty(c, propertyName, null);
}
Member member = findMember(c, propertyName);
if ( member!=null ) {
try {
if (member instanceof Method) {
return ((Method)member).invoke(o);
}
else if (member instanceof Field) {
return ((Field)member).get(o);
}
}
catch (Exception e) {
throwNoSuchProperty(c, propertyName, e);
}
}
return throwNoSuchProperty(c, propertyName, null);
}
protected static Member findMember(Class<?> clazz, String memberName) {
if (clazz == null) {
throw new NullPointerException("clazz");
}
if (memberName == null) {
throw new NullPointerException("memberName");
}
synchronized (membersCache) {
Map<String, Member> members = membersCache.get(clazz);
Member member = null;
if (members != null) {
member = members.get(memberName);
if (member != null) {
return member != INVALID_MEMBER ? member : null;
}
}
else {
members = new HashMap<String, Member>();
membersCache.put(clazz, members);
}
// try getXXX and isXXX properties, look up using reflection
String methodSuffix = Character.toUpperCase(memberName.charAt(0)) +
memberName.substring(1, memberName.length());
member = tryGetMethod(clazz, "get" + methodSuffix);
if (member == null) {
member = tryGetMethod(clazz, "is" + methodSuffix);
if (member == null) {
member = tryGetMethod(clazz, "has" + methodSuffix);
}
}
if (member == null) {
// try for a visible field
member = tryGetField(clazz, memberName);
}
members.put(memberName, member != null ? member : INVALID_MEMBER);
return member;
}
}
protected static Method tryGetMethod(Class<?> clazz, String methodName) {
try {
Method method = clazz.getMethod(methodName);
if (method != null) {
method.setAccessible(true);
}
return method;
} catch (NoSuchMethodException ex) {
} catch (SecurityException ex) {
}
return null;
}
protected static Field tryGetField(Class<?> clazz, String fieldName) {
try {
Field field = clazz.getField(fieldName);
if (field != null) {
field.setAccessible(true);
}
return field;
} catch (NoSuchFieldException ex) {
} catch (SecurityException ex) {
}
return null;
}
protected Object throwNoSuchProperty(Class<?> clazz, String propertyName, Exception cause) {
throw new STNoSuchPropertyException(cause, null, clazz.getName() + "." + propertyName);
}
}