SetterlessProperty.java

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

import java.io.IOException;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.JsonToken;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.JsonDeserializer;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.deser.SettableBeanProperty;
import com.fasterxml.jackson.databind.introspect.AnnotatedMember;
import com.fasterxml.jackson.databind.introspect.AnnotatedMethod;
import com.fasterxml.jackson.databind.introspect.BeanPropertyDefinition;
import com.fasterxml.jackson.databind.jsontype.TypeDeserializer;
import com.fasterxml.jackson.databind.util.Annotations;

/**
 * This concrete sub-class implements Collection or Map property that is
 * indirectly by getting the property value and directly modifying it.
 */
public final class SetterlessProperty
    extends SettableBeanProperty
{
    private static final long serialVersionUID = 1L;

    protected final AnnotatedMethod _annotated;

    /**
     * Get method for accessing property value used to access property
     * (of Collection or Map type) to modify.
     */
    protected final Method _getter;

    public SetterlessProperty(BeanPropertyDefinition propDef, JavaType type,
            TypeDeserializer typeDeser, Annotations contextAnnotations, AnnotatedMethod method)
        {
        super(propDef, type, typeDeser, contextAnnotations);
        _annotated = method;
        _getter = method.getAnnotated();
    }

    protected SetterlessProperty(SetterlessProperty src, JsonDeserializer<?> deser) {
        super(src, deser);
        _annotated = src._annotated;
        _getter = src._getter;
    }

    protected SetterlessProperty(SetterlessProperty src, String newName) {
        super(src, newName);
        _annotated = src._annotated;
        _getter = src._getter;
    }

    @Override
    public SetterlessProperty withName(String newName) {
        return new SetterlessProperty(this, newName);
    }
    
    @Override
    public SetterlessProperty withValueDeserializer(JsonDeserializer<?> deser) {
        return new SetterlessProperty(this, deser);
    }
    
    /*
    /**********************************************************
    /* BeanProperty impl
    /**********************************************************
     */
    
    @Override
    public <A extends Annotation> A getAnnotation(Class<A> acls) {
        return _annotated.getAnnotation(acls);
    }

    @Override public AnnotatedMember getMember() {  return _annotated; }

    /*
    /**********************************************************
    /* Overridden methods
    /**********************************************************
     */
    
    @Override
    public final void deserializeAndSet(JsonParser jp, DeserializationContext ctxt,
            Object instance)
        throws IOException, JsonProcessingException
    {
        JsonToken t = jp.getCurrentToken();
        if (t == JsonToken.VALUE_NULL) {
            /* Hmmh. Is this a problem? We won't be setting anything, so it's
             * equivalent of empty Collection/Map in this case
             */
            return;
        }

        // Ok: then, need to fetch Collection/Map to modify:
        Object toModify;
        try {
            toModify = _getter.invoke(instance);
        } catch (Exception e) {
            _throwAsIOE(e);
            return; // never gets here
        }
        /* Note: null won't work, since we can't then inject anything
         * in. At least that's not good in common case. However,
         * theoretically the case where we get JSON null might
         * be compatible. If so, implementation could be changed.
         */
        if (toModify == null) {
            throw new JsonMappingException("Problem deserializing 'setterless' property '"+getName()+"': get method returned null");
        }
        _valueDeserializer.deserialize(jp, ctxt, toModify);
    }

    @Override
    public Object deserializeSetAndReturn(JsonParser jp,
    		DeserializationContext ctxt, Object instance)
        throws IOException, JsonProcessingException
    {
    	deserializeAndSet(jp, ctxt, instance);
    	return instance;
    }
    
    @Override
    public final void set(Object instance, Object value)
        throws IOException
    {
        throw new UnsupportedOperationException("Should never call 'set' on setterless property");
    }

    @Override
    public Object setAndReturn(Object instance, Object value)
            throws IOException
    {
    	set(instance, value);
    	return null;
    }
}