Spring JSON Serializer and Deserializer is not getting called

Question

I have written custom serializer and deserializer for com.google.common.collect.Table class. But it is not getting called while persisting that object in MongoDB. I am using Spring 4, Spring-MongoDB 1.9 and Jackson 2.8.4. Below are the class and configuration. Could you please let me know what's wrong with this. I want these class to be called while persisting and retrieving from MongoDB.

public class TableSeserializer extends StdSerializer<Table> {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    public TableSeserializer() {
        this(Table.class);
    }

    public TableSeserializer(Class<Table> t) {
        super(t);
    }

    @SuppressWarnings("unchecked")
    @Override
    public void serialize(Table value, JsonGenerator gen, SerializerProvider provider)
            throws IOException {
        gen.writeStartObject();
        value.rowMap().forEach((i,map) ->{
            try {
                gen.writeNumber((int)i);
                ((Map)map).forEach((k,v)->{
                    try {
                        gen.writeStartObject();
                        Object object = ((Map)map).get(k);
                        if (object instanceof HTMLInputTag) {
                            HTMLInputTag inputTag = (HTMLInputTag) object;
                            gen.writeObjectField(inputTag.getId(),inputTag);
                        }else{
                            gen.writeObjectField(object.toString(),object);
                        }

                        gen.writeEndObject();

                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                });

            } catch (IOException e) {
                e.printStackTrace();
            }
        });
        gen.writeEndObject();
    }
}

public class TableDeserializer extends StdDeserializer<Table<Integer, String, HTMLInputTag>> {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    protected TableDeserializer(Class<?> vc) {
        super(vc);
    }

    public TableDeserializer() { 
        this(null); 
    }

    @Override
    public Table<Integer, String, HTMLInputTag> deserialize(JsonParser jsonparser, DeserializationContext ctxt)
            throws IOException, JsonProcessingException {
        String data = jsonparser.getText();
        ObjectMapper mapper = new ObjectMapper();
        JsonNode node = mapper.readTree(data);


        return null;
    }

}

Spring configuration

@Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        SimpleModule module = new SimpleModule();
        module.addSerializer(Table.class, new TableSeserializer());
        module.addDeserializer(Table.class, new TableDeserializer());
        Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder().modules(module);

        converters.add(jacksonConverter(builder));
    }

    @Bean
    MappingJackson2HttpMessageConverter jacksonConverter(Jackson2ObjectMapperBuilder builder) {
        return new MappingJackson2HttpMessageConverter(builder.build());
    }

Annotation in class

public class OrganizationAttributeMetaData extends CommonDomainAttributes implements Cloneable, Serializable {

    /**
     *
     */
    private static final long serialVersionUID = 1L;

    private String attributeName;
    private int orgid;
    private String uniquecode; //3 Character unique code to uniquely identify

    @JsonDeserialize(using=TableDeserializer.class)
    @JsonSerialize(using=TableSeserializer.class)
    Table<Integer, String, HTMLInputTag> htmlAttributes = null; //row,identifier and HTML

}

Spring mongo db uses mongo db's serialization/ deserialization. You will need to convert these Jackson serializers/deserializers to spring converters and register them with mongo mapping converters. — s7vr

Rafal G. Rafal G. · Accepted Answer · 2017-01-01T19:28:49

You really mixed some things ;) MongoDB indeed stores data in JSON-like format (BSON - Binary JSON) but it has nothing to do with Jackson - which is used (like the way you showed) to serialize/deserialize objects sent over HTTP.

In Spring Data MongoDB you need to implement and configure custom converters. More about that can be read here.

Spring JSON Serializer and Deserializer is not getting called

1 Answers