Chapter 13. Red Hat build of Keycloak admin client

The Red Hat build of Keycloak admin client aims to work with multiple versions of the Red Hat build of Keycloak server. The admin client may be supported with a newer version of the Red Hat build of Keycloak server that is released later than the client and older versions of the Red Hat build of Keycloak server that were released earlier. As a result of this change, the Java fields of the underlying "representation" classes, which are representing JSON properties of the request/response body (such as the RealmRepresentation class shown in the previous section) might not be exactly same for the client and the server.

To avoid compatibility issues, ensure that the com.fasterxml.jackson.databind.ObjectMapper class, which is used by the admin client under the covers, is initialized with these two properties:

objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);

If you are using the basic ways of admin client creation as described above, then these properties are added by default as admin client uses by default the org.keycloak.admin.client.JacksonProvider class for creating ObjectMapper, which adds these properties automatically. However if you are injecting your own customJacksonProvider when creating Keycloak object, make sure that object mapper is initialized with the properties above if you want to avoid compatibility issues.

For example, consider the situation that the admin client is instantiated in a way as described below with your own MyCustomJacksonProvider class:

Keycloak.getInstance(
                "http://localhost:8080",
                "master",
                "admin",
                "admin",
                "admin-cli",
                null,
                null,
                new MyCustomJacksonProvider()
        );

Keycloak.getInstance(
                "http://localhost:8080",
                "master",
                "admin",
                "admin",
                "admin-cli",
                null,
                null,
                new MyCustomJacksonProvider()
        );

In this case, please make sure that your class MyCustomJacksonProvider extends from the class org.keycloak.admin.client.JacksonProvider or make sure to configure the ObjectMapper manually in a way described above. The similar care should be taken when using KeycloakBuilder to create the admin client and the RestEasy client is manually injected and created.