package org.osgl.util;
import java.io.Serializable;
public interface PropertyGetter extends Serializable, PropertyHandler {
public static enum NullValuePolicy {
/**
* Return {@code null} when {@code null} value encountered.
* This is the default policy
*/
RETURN_NULL,
/**
* Throws {@link NullPointerException} when {@code null} value encountered
*/
NPE,
/**
* Create new instance when {@code null} value encountered.
* This is useful when use {@link PropertyGetter} along with {@link PropertySetter}
* to set a value on a property path. E.g. set "a string" to {@code "bar.0.zee"} on
* {@code foo} entity
*/
CREATE_NEW
}
/**
* Set null value policy
* @param nvp the policy
*/
void setNullValuePolicy(NullValuePolicy nvp);
/**
* Get the property value from an entity
* @param entity the entity object
* @param index optional index, used when the property is a {@link java.util.List} or {@link java.util.Map}
* @return the property value
*/
Object get(Object entity, Object index);
/**
* Returns the corresponding setter
* @return the setter
*/
PropertySetter setter();
}