de.intarsys.tools.reflect.ReflectionRelationHandler Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of isrt Show documentation

The basic runtime tools and interfaces for intarsys components.

There is a newer version: 4.11

package de.intarsys.tools.reflect;

import java.lang.reflect.Method;
import java.util.Collection;

/**
 * The relation is implemented using plain JDK reflection.
 * 
 */
public class ReflectionRelationHandler extends RelationHandlerAdapter {

	final private Method getter;

	final private Method inserter;

	final private Method remover;

	public ReflectionRelationHandler(Method getter, Method inserter,
			Method remover) {
		super();
		this.getter = getter;
		this.inserter = inserter;
		this.remover = remover;
	}

	@Override
	public Object[] get(Object owner) {
		try {
			Object value = getter.invoke(owner, (Object[]) null);
			if (value instanceof Collection) {
				return ((Collection) value).toArray();
			}
			if (value instanceof Object[]) {
				return (Object[]) value;
			}
		} catch (Exception e) {
			//
		}
		return new Object[0];
	}

	@Override
	public Object insert(Object owner, Object value) {
		try {
			return inserter.invoke(owner, new Object[] { value });
		} catch (Exception e) {
			return null;
		}
	}

	@Override
	public Object remove(Object owner, Object value) {
		try {
			return remover.invoke(owner, new Object[] { value });
		} catch (Exception e) {
			return null;
		}
	}

	@Override
	public Object update(Object owner, Object value, Object newValue) {
		try {
			remover.invoke(owner, new Object[] { value });
			return inserter.invoke(owner, new Object[] { newValue });
		} catch (Exception e) {
			return null;
		}
	}

}