Fast reflective field access

FieldAccess.java

import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.reflect.Field;

/**
 * @author vadim
 */
public class FieldAccess {

	private final Field field;
	private final MethodHandle set, get;

	private final RuntimeException err(String s, Throwable t) {
		return new RuntimeException("Unable to "+s+" for field "+field.getDeclaringClass().getCanonicalName()+"#"+field.getName(), t);
	}

	public FieldAccess(Field field) {
		this.field = field;

		MethodHandles.Lookup lookup;
		try {
			lookup = MethodHandles.privateLookupIn(field.getDeclaringClass(), MethodHandles.lookup());
		} catch (Exception e) {
			throw err("create a private lookup", e);
		}

		try {
			set = lookup.unreflectSetter(field);
		} catch (Exception e) {
			throw err("unreflect setter", e);
		}

		try {
			get = lookup.unreflectGetter(field);
		} catch (Exception e) {
			throw err("unreflect getter", e);
		}
	}

	public Object get(Object instance) {
		try {
			return get.invoke(instance);
		} catch (Throwable t) {
			throw err("invoke getter", t);
		}
	}

	public void set(Object instance, Object value) {
		try {
			set.invoke(instance, value);
		} catch (Throwable t) {
			throw err("invoke setter", t);
		}
	}

}