bundles/runtime/org.eclipse.fx.core/src/org/eclipse/fx/core/ReflectionUtil.java

/*******************************************************************************
 * Copyright (c) 2014 EM-SOFTWARE and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Christoph Keimel <c.keimel@emsw.de> - initial API and implementation
 *******************************************************************************/
package org.eclipse.fx.core;

import java.lang.reflect.Field;

/**
 * Utility Functions using the Java Reflection API
 */
public class ReflectionUtil {

	/**
	 * Searches for a field in the given class and all of its super classes.
	 * @param clazz Class to start the search for the field
	 * @param name Name of the field
	 * @return The field that was found
	 * @throws NoSuchFieldException
	 */
	public static Field getField(Class<?> clazz, String name) throws NoSuchFieldException {
		Class<?> searchClass = clazz;
		Field field = null;
		while (field == null && searchClass != null) {
			try {
				field = searchClass.getDeclaredField(name);
			} catch (NoSuchFieldException e) {
				searchClass = searchClass.getSuperclass();
			}
		}
		if (field == null) {
			throw new NoSuchFieldException(clazz.getSimpleName() + "." + name); //$NON-NLS-1$
		}
		return field;
	}
	
	/**
	 * Utility method to set a field to a value. If the field is not accessible, it will be set to be accessible.
	 * @param object Instance in which the value should be set
	 * @param name Name of the field who's value should be set
	 * @param value The value to be set
	 */
	public static void setFieldValue(Object object, String name, Object value) {
		try {
			Field field = getField(object.getClass(), name);
			if (!field.isAccessible()) {
				field.setAccessible(true);
			}
			field.set(object, value);
		} catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException e) {
			throw new RuntimeException("Could not set field value: " + object.getClass().getSimpleName() + "." + name, e); //$NON-NLS-1$ //$NON-NLS-2$
		}
		
	}

	/**
	 * Utility method to read a field value. If the field is not accessible, it will be set to be accessible.
	 * @param object Instance in which the value should be read
	 * @param name Name of the field who's value should be read
	 * @return The value of the field
	 */
	public static Object getFieldValue(Object object, String name) {
		try {
			Field field = getField(object.getClass(), name);
			if (!field.isAccessible()) {
				field.setAccessible(true);
			}
			return field.get(object);
		} catch (NoSuchFieldException | SecurityException | IllegalArgumentException | IllegalAccessException e) {
			throw new RuntimeException("Could not read field value: " + object.getClass().getSimpleName() + "." + name, e); //$NON-NLS-1$ //$NON-NLS-2$
		}
	}

}