@JsonAnySetter

@JsonAnySetter allows you the flexibility of using a Map as a standard properties. On de-serialization, the properties from JSON will simply be added to the map.

Let's see how this works - we'll use @JsonAnySetter to deserialize the entity ExtendableBean:

public class ExtendableBean {
    public String name;

    private Map<String, String> properties = new HashMap<>();


    @JsonAnySetter
    public void add(String key, String value) {
        properties.put(key, value);
    }

    @Override
    public String toString() {
        return "ExtendableBean{" +
                "name='" + name + '\'' +
                ", properties=" + properties +
                '}';
    }
}

This is the JSON we need to deserialize:

{
    "name": "My bean",
    "attr2": "val2",
    "attr1": "val1"
}

And here's how this all ties in together:

    @Test
    public void test01() throws IOException {
        ObjectMapper mapper = new ObjectMapper();

        String json
                = "{\"name\":\"My bean\",\"attr2\":\"val2\",\"attr1\":\"val1\", \"attr11\":\"val11\", \"attr1\":\"val11111\"}";

        ExtendableBean extendableBean = mapper.readValue(json, ExtendableBean.class);
        System.out.println(extendableBean);

        Assert.assertEquals("val11111", extendableBean.getProperties().get("attr1"));
        Assert.assertEquals("val11", extendableBean.getProperties().get("attr11"));
    }