gistfile1.java

package de.oppermann.bastian.lib.miscellaneous;

import java.lang.reflect.Field;

/**
 * Class that helps with reflection.
 */
public class ReflectionUtil {

	// no instance
	private ReflectionUtil() { }
	
	/**
	 * Gets a {@link Field} from a Object with a given name.
	 * 
	 * @param from The object that contains the field.
	 * @param name The name of the field.
	 * @return The field with the given name. <code>null</code> if there is no field with this name.
	 */
	@SuppressWarnings("unchecked")
	public static <T> T getField(Object from, String name) {
		if (from == null)
			throw new IllegalArgumentException("from cannot be null");
		if (name == null)
			throw new IllegalArgumentException("name cannot be null");
		Class<?> checkClass = from.getClass();
		do {
			try {
				Field field = checkClass.getDeclaredField(name);
				field.setAccessible(true);
				return (T) field.get(from);
			} catch (NoSuchFieldException e) { } catch (IllegalAccessException e) { }
		} while (checkClass.getSuperclass() != Object.class && ((checkClass = checkClass.getSuperclass()) != null));
		return null;
	}

	/**
	 * Sets the value of a private field.
	 * 
	 * @param object The object.
	 * @param name The name of the field.
	 * @param value The value to set.
	 */
	public static void setPrivateField(Object object, String name, Object value) {
		if (object == null)
			throw new IllegalArgumentException("from cannot be null");
		if (name == null)
			throw new IllegalArgumentException("name cannot be null");
		Class<?> checkClass = object.getClass();
		do {
			try {
				Field field = checkClass.getDeclaredField(name);
				field.setAccessible(true);
				field.set(object, value);
			} catch (NoSuchFieldException e) { } catch (IllegalAccessException e) { }
		} while (checkClass.getSuperclass() != Object.class && ((checkClass = checkClass.getSuperclass()) != null));
	}
	
}