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/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 2014 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
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* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
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* and therefore, elected the GPL Version 2 license, then the option applies
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*/
package org.glassfish.hk2.utilities.reflection;
import java.beans.Introspector;
import java.beans.PropertyChangeEvent;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.Map;
import java.util.Set;
import org.glassfish.hk2.utilities.general.GeneralUtilities;
/**
* @author jwells
*
*/
public class BeanReflectionHelper {
private final static String GET = "get";
private final static String IS = "is";
/**
* Returns the bean version of the property name if the method
* is a getter, or returns null if the method is not a getter
*
* @param method The method to get the property name from
* @return The java-bean version of the property name or null
* if the method is not a java-bean getter
*/
public static String getBeanPropertyNameFromGetter(final Method method) {
return isAGetter(new MethodWrapper() {
@Override
public Method getMethod() {
return method;
}
});
}
/**
* Returns the property name if this is a getter
*
* @param method The method to investigate for being a property
* @return The property name or null if not a getter
*/
private static String isAGetter(MethodWrapper method) {
Method m = method.getMethod();
String name = m.getName();
if (void.class.equals(m.getReturnType())) {
// Only methods that return something
return null;
}
Class params[] = m.getParameterTypes();
if (params.length != 0) {
// Only methods with no arguments
return null;
}
if ((m.getModifiers() & Modifier.PUBLIC) == 0) {
// Only public methods
return null;
}
int capIndex;
if (name.startsWith(GET) && (name.length() > GET.length())) {
capIndex = GET.length();
}
else if (name.startsWith(IS) && (name.length() > IS.length())) {
capIndex = IS.length();
}
else {
// Only method that start with is or get
return null;
}
if (!Character.isUpperCase(name.charAt(capIndex))) {
// Only methods whose next letter is uppercase
return null;
}
String rawPropName = name.substring(capIndex);
return Introspector.decapitalize(rawPropName);
}
private static Method findMethod(Method m, Class c) {
String name = m.getName();
Class params[] = new Class[0];
try {
return c.getMethod(name, params);
}
catch (Throwable th) {
return null;
}
}
private static Object getValue(Object bean, Method m) {
try {
return m.invoke(bean, new Object[0]);
}
catch (Throwable th) {
return null;
}
}
private static PropertyChangeEvent[] getMapChangeEvents(Map oldBean, Map newBean) {
LinkedList retVal = new LinkedList();
for (Map.Entry entry : oldBean.entrySet()) {
String key = entry.getKey();
Object oldValue = entry.getValue();
Object newValue = newBean.get(key);
if (!GeneralUtilities.safeEquals(oldValue, newValue)) {
retVal.add(new PropertyChangeEvent(newBean,
key,
oldValue,
newValue));
}
}
return retVal.toArray(new PropertyChangeEvent[retVal.size()]);
}
/**
* Gets the set of change events by comparing two different beans. If the beans implement Map
* then they are considered to be bean-like maps
*
* @param helper A ClassReflectionHelper to use for analyzing classes
* @param oldBean a non-null current bean
* @param newBean a non-null new bean
* @return a possibly zero length but never null list of the change events between the two beans
*/
@SuppressWarnings("unchecked")
public static PropertyChangeEvent[] getChangeEvents(ClassReflectionHelper helper, Object oldBean, Object newBean) {
if (oldBean instanceof Map) {
return getMapChangeEvents((Map) oldBean, (Map) newBean);
}
LinkedList retVal = new LinkedList();
Set methods = helper.getAllMethods(oldBean.getClass());
for (MethodWrapper wrapper : methods) {
String propName = isAGetter(wrapper);
if (propName == null) continue;
Method method = wrapper.getMethod();
Method newMethod = findMethod(method, newBean.getClass());
if (newMethod == null) continue;
Object oldValue = getValue(oldBean, method);
Object newValue = getValue(newBean, newMethod);
if (GeneralUtilities.safeEquals(oldValue, newValue)) continue;
// Has changed!
retVal.add(new PropertyChangeEvent(newBean,
propName,
oldValue,
newValue));
}
return retVal.toArray(new PropertyChangeEvent[retVal.size()]);
}
/**
* Converts a Java bean to a bean-like Map
*
* @param helper A ClassReflectionHelper to use for analyzing classes
* @param bean a non-null bean to convert
* @return a possibly zero length but never null bean-like map. All properties of the bean are filled
* in, even if the value of the property is null
*/
public static Map convertJavaBeanToBeanLikeMap(ClassReflectionHelper helper, Object bean) {
HashMap retVal = new HashMap();
Set methods = helper.getAllMethods(bean.getClass());
for (MethodWrapper wrapper : methods) {
String propName = isAGetter(wrapper);
if (propName == null) continue;
if ("class".equals(propName)) continue;
Method method = wrapper.getMethod();
Object value = getValue(bean, method);
retVal.put(propName, value);
}
return retVal;
}
}