Using Jackson to create manually a JsonNode

JsonJacksonTest.java

/** 
* Manually, no big deal
* ObjectNode representes a Json. When you create a HTTP Post, this object should be enough or send it as a converted String
**/
public class JsonJacksonTest {

    @Test
    public void testJsonByHand() {
        ObjectMapper objectMapper = new ObjectMapper();

        ObjectNode objectNode = objectMapper.createObjectNode();

        objectNode.put("attribute1", "value1");
        objectNode.put("attribute2", "value2");

        System.out.println(objectNode.toString());

    }
}

/** Using Custom Serializer example **/

public class CountrySerializer extends StdSerializer<Country> {

    protected CountrySerializer(Class<Country> t) {
        super(t);
    }
    public CountrySerializer() {
        this(null);
    }
    @Override
    public void serialize(Country country, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {
        jsonGenerator.writeStartObject();
        jsonGenerator.writeStringField("countryName", country.getDisplayName());
        jsonGenerator.writeEndObject();
    }
}

/** 
* This also works. You can use Jackson ObjectMapper to convert a Country object to Json String configuring it to use the 
* custom serializer.
**/
public class JacksonCustomSerializer {

    @Test
    public void testCustomCountrySerializer() throws JsonProcessingException {
        Country country = new Country();
        country.setDisplayName("Wakanda");

        ObjectMapper mapper = new ObjectMapper();

        SimpleModule module = new SimpleModule();
        module.addSerializer(Country.class, new CountrySerializer());
        mapper.registerModule(module);

        String serialized = mapper.writeValueAsString(country);
        System.out.println(serialized);

    }
}