package com.fasterxml.jackson.databind.ser.impl;

import com.fasterxml.jackson.annotation.ObjectIdGenerator;
import com.fasterxml.jackson.annotation.ObjectIdGenerators;

import com.fasterxml.jackson.databind.introspect.ObjectIdInfo;
import com.fasterxml.jackson.databind.ser.*;

public class PropertyBasedObjectIdGenerator
    extends ObjectIdGenerators.PropertyGenerator
{
    private static final long serialVersionUID = 1L;

    protected final BeanPropertyWriter _property;
    
    public PropertyBasedObjectIdGenerator(ObjectIdInfo oid, BeanPropertyWriter prop)
    {
        this(oid.getScope(), prop);
    }

    protected PropertyBasedObjectIdGenerator(Class<?> scope, BeanPropertyWriter prop)
    {
        super(scope);
        _property = prop;
    }

    
We must override this method, to prevent errors when scopes are the same, but underlying class (on which to access property) is different.
/** * We must override this method, to prevent errors when scopes are the same, * but underlying class (on which to access property) is different. */
@Override public boolean canUseFor(ObjectIdGenerator<?> gen) { if (gen.getClass() == getClass()) { PropertyBasedObjectIdGenerator other = (PropertyBasedObjectIdGenerator) gen; if (other.getScope() == _scope) { /* 26-Jul-2012, tatu: This is actually not enough, because the property * accessor within BeanPropertyWriter won't work for other property fields * (see [https://github.com/FasterXML/jackson-module-jaxb-annotations/issues/9] * for details). * So we need to verify that underlying property is actually the same. */ return (other._property == _property); } } return false; } @Override public Object generateId(Object forPojo) { try { return _property.get(forPojo); } catch (RuntimeException e) { throw e; } catch (Exception e) { throw new IllegalStateException("Problem accessing property '" +_property.getName()+"': "+e.getMessage(), e); } } @Override public ObjectIdGenerator<Object> forScope(Class<?> scope) { return (scope == _scope) ? this : new PropertyBasedObjectIdGenerator(scope, _property); } @Override public ObjectIdGenerator<Object> newForSerialization(Object context) { // No state, can return this return this; } @Override public com.fasterxml.jackson.annotation.ObjectIdGenerator.IdKey key(Object key) { if (key == null) { return null; } // should we use general type for all; or type of property itself? return new IdKey(getClass(), _scope, key); } }