/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jbpm.instantiation;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.Collection;
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.SortedMap;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.jbpm.JbpmException;
import org.jbpm.util.ClassLoaderUtil;
public class FieldInstantiator implements Instantiator {
public Object instantiate(Class clazz, String configuration) {
// create a new instance with the default constructor
Object newInstance = newInstance(clazz);
if (configuration != null && configuration.length() > 0) {
// parse the bean configuration
Element configurationElement = parseConfiguration(configuration);
// loop over the configured properties
for (Iterator iter = configurationElement.elementIterator(); iter.hasNext();) {
Element propertyElement = (Element) iter.next();
String propertyName = propertyElement.getName();
setPropertyValue(clazz, newInstance, propertyName, propertyElement);
}
}
return newInstance;
}
protected void setPropertyValue(Class clazz, Object instance, String propertyName,
Element propertyElement) {
Field field = findField(clazz, propertyName);
if (field != null) {
field.setAccessible(true);
Object value = getValue(field.getType(), propertyElement);
try {
field.set(instance, value);
}
catch (IllegalArgumentException e) {
log.error("could not set '" + propertyName + "' to: " + value, e);
}
catch (IllegalAccessException e) {
log.error(getClass() + " has no access to " + field, e);
}
}
else {
log.error("field not found: " + propertyName);
}
}
private Field findField(Class clazz, String propertyName) {
do {
try {
return clazz.getDeclaredField(propertyName);
}
catch (NoSuchFieldException e) {
clazz = clazz.getSuperclass();
}
} while (clazz != null);
return null;
}
protected Element parseConfiguration(String configuration) {
try {
return DocumentHelper.parseText("<action>" + configuration + "</action>")
.getRootElement();
}
catch (DocumentException e) {
throw new JbpmException("failed to parse configuration", e);
}
}
protected Object newInstance(Class clazz) {
try {
return clazz.newInstance();
}
catch (InstantiationException e) {
throw new JbpmException("failed to instantiate " + clazz, e);
}
catch (IllegalAccessException e) {
throw new JbpmException(getClass() + " has no access to " + clazz, e);
}
}
public static Object getValue(Class type, Element propertyElement) {
// parse the value
Object value = null;
if (type == String.class) {
value = propertyElement.getText();
}
else if (type == Integer.class || type == int.class) {
value = new Integer(propertyElement.getTextTrim());
}
else if (type == Long.class || type == long.class) {
value = new Long(propertyElement.getTextTrim());
}
else if (type == Float.class || type == float.class) {
value = new Float(propertyElement.getTextTrim());
}
else if (type == Double.class || type == double.class) {
value = new Double(propertyElement.getTextTrim());
}
else if (type == Boolean.class || type == boolean.class) {
value = Boolean.valueOf(propertyElement.getTextTrim());
}
else if (type == Character.class || type == char.class) {
value = new Character(propertyElement.getTextTrim().charAt(0));
}
else if (type == Short.class || type == short.class) {
value = new Short(propertyElement.getTextTrim());
}
else if (type == Byte.class || type == byte.class) {
value = new Byte(propertyElement.getTextTrim());
}
else if (type == List.class || type == Collection.class) {
value = getCollection(propertyElement, new ArrayList());
}
else if (type == Set.class) {
value = getCollection(propertyElement, new HashSet());
}
else if (type == SortedSet.class) {
value = getCollection(propertyElement, new TreeSet());
}
else if (type == Map.class) {
value = getMap(propertyElement, new HashMap());
}
else if (type == SortedMap.class) {
value = getMap(propertyElement, new TreeMap());
}
else if (Element.class.isAssignableFrom(type)) {
value = propertyElement;
}
else {
try {
if (Collection.class.isAssignableFrom(type)) {
value = getCollection(propertyElement, (Collection) type.newInstance());
}
else if (Map.class.isAssignableFrom(type)) {
value = getMap(propertyElement, (Map) type.newInstance());
}
else if (propertyElement.isTextOnly()) {
Constructor constructor = type.getConstructor(new Class[] {
String.class
});
try {
value = constructor.newInstance(new Object[] {
propertyElement.getTextTrim()
});
}
catch (IllegalAccessException e) {
log.error(FieldInstantiator.class + " has no access to " + constructor);
}
catch (InvocationTargetException e) {
log.error(constructor + " threw exception", e.getCause());
}
}
else {
log.error("element '" + propertyElement.getName() + "' has non-text content");
}
}
catch (InstantiationException e) {
log.error("failed to instantiate " + type, e);
}
catch (IllegalAccessException e) {
log.error(FieldInstantiator.class + " has no access to " + type, e);
}
catch (NoSuchMethodException e) {
log.error("constructor not found: " + type.getName() + "(String)", e);
}
}
return value;
}
private static Map getMap(Element mapElement, Map map) {
Class keyClass = classForAttributeValue(mapElement, "key-type");
Class valueClass = classForAttributeValue(mapElement, "value-type");
for (Iterator iter = mapElement.elementIterator(); iter.hasNext();) {
Element element = (Element) iter.next();
Element keyElement = element.element("key");
Element valueElement = element.element("value");
map.put(getValue(keyClass, keyElement), getValue(valueClass, valueElement));
}
return map;
}
private static Object getCollection(Element collectionElement, Collection collection) {
Class elementClass = classForAttributeValue(collectionElement, "element-type");
for (Iterator iter = collectionElement.elementIterator(); iter.hasNext();) {
Element element = (Element) iter.next();
collection.add(getValue(elementClass, element));
}
return collection;
}
/**
* Returns the <code>Class</code> associated with the value for the attribute with the given
* name.
*/
private static Class classForAttributeValue(Element element, String attributeName) {
String className = element.attributeValue(attributeName);
if (className != null) {
try {
return ClassLoaderUtil.classForName(className);
}
catch (ClassNotFoundException e) {
throw new JbpmException("no such class " + className, e);
}
}
return String.class;
}
private static final Log log = LogFactory.getLog(FieldInstantiator.class);
}