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javajsondeserializationflexjson

FlexJSON Exclude Properties Upon Deserialization


I'm receiving a JSON response from a web service, but for various reasons I don't want to have certain properties deserialized in the final response object. For example I have:

public class Foo {
    private String bar;
    private int baz;

    //getters & setters
}

The JSON response I'm getting back has both properties, but upon deserialization I don't want "bar" to be set. The reason for this is that the property they're sending is a long, but ours is a String, so deserializing throws an IllegalArgumentException.

Another option would be to parse the JSON with something like json-simple, remove the properties I want, convert it back to JSON and pass that into the deserializer, but I'd like to avoid that if possible since the JSON is pretty large.

Is there a way to do this with an ObjectFactory perhaps?


Solution

  • Yes an ObjectFactory could be used to allow a conversion from Long to String. Simply register the ObjectFactory on your path like:

    new JSONDeserializer().use("some.path.to.bar", new EnhancedStringObjectFactory() ).deserialize( json, new SomeObject() );
    
    
    
    public class EnhancedStringObjectFactory implements ObjectFactory {
        public Object instantiate(ObjectBinder context, Object value, Type targetType, Class targetClass) {
            if( value instanceof String ) {
                return value;
            } else if( value instanceof Number ) {
                return ((Number)value).toString();
            } else {
               throw context.cannotConvertValueToTargetType(value, String.class);
            }
       }
    }
    

    You could even register that as the default ObjectFactory for String and it would handle that case for any String coming into the deserializer:

    new JSONDeserializer().use( String.class, new EnhancedStringObjectFactory() ).deserialize( json, new SomeObject() );