Areas where Jackson is Used:
...
- Direct usage of Jackson by Portal code
...
- Indirect dependency through other packages
- Frameworks configured with Jackson like Spring Boot
Modules with direct dependency on Jackson package:
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- com.orbitz.consul:consul-client:jar - Excluded the jacskon dependency for this package and ran the build. The build is successful, however this needs to tested with real time scenarios.
- org.elasticsearch:elasticsearch:jar - Not using this package anywhere in the code and can be removed, as confirmed by Sunder
- Spring Boot
Code Analysis:
- Portal-SDK: Approximately 60+ files that inculde fatserxml jackson excluding test files.
- Portal: Approximately 60+ files that inculde fatserxml jackson excluding test files
...
Output for both methods, gson.fromJson() and mapper.readValue, is same
Replacing spring Boot Jackson dependencies with Gson:
https://www.callicoder.com/configuring-spring-boot-to-use-gson-instead-of-jackson/
Jackson Methods used in our code and their equivalents in Gson:
Below are few of the methods and their usages in Gson that can be used as replacements for Jackson,
| Jackson Method | Jackson Class | Usage | GSON Equivalent Method | GSON Equivalent Class | Usage |
|---|---|---|---|---|---|
| readValue | jackson.databind.ObjectMapper | <ObjectType> obj = mapper.readValue(JsonString, ClassType); | fromJson | com.google.gson.Gson; | <ObjectType> obj = gson.fromJson(data, RoleFunction.class); |
| writeValueAsString | jackson.databind.ObjectMapper | String json = new ObjectMapper().writeValueAsString(Object); | toJson | com.google.gson.Gson; | String resultJson = new Gson().toJson(Object); |
| configure | jackson.databind.ObjectMapper | objectMapper.configure(com.fasterxml.jackson.databind.SerializationFeature.WRITE_DATES_AS_TIMESTAMPS) objectMapper.disable(DeserializationFeature.FAIL_ON_NULL_FOR_PRIMITIVES) | Use GsonBuilder to construct a Gson instance when you need to set configuration options other than the default | com.google.gson.GsonBuilder | Gson gson = new GsonBuilder() .serializeNulls() .setDateFormat(DateFormat.LONG) .create(); |
| readTree | jackson.databind.ObjectMapper | JsonNode root = mapper.readTree(request.getReader()); | parse | com.google.gson.JsonParser | JsonElement rootNode = parser.parse(jsonString); |
| NA | jackson.databind.JsonNode; | Base class for all JSON nodes, which form the basis of JSON | NA | import com.google.gson.JsonElement; | class representing an element of Json. It could either be a JsonObject, a JsonArray, a JsonPrimitive or a JsonNull |
| NA | jackson.core.type.TypeReference | TypeReference<List<Type>> typeRef = new TypeReference<List<Type>>() {}; List<Type> listObj = mapper.readValue(requestBody, typeRef); | NA | import com.google.gson.reflect.TypeToken; | listObj = gson.fromJson(jsonString, new TypeToken<Hashtable<String, Type>>() {}.getType()); |
| NA | import com.fasterxml.jackson.databind.type.TypeFactory; | NA | |||
| NA | jackson.annotation.JsonIgnoreProperties; | JsonIgnoreProperties(ignoreUnknown = true) | NA | com.google.gson.annotations.Expose | GSON @Expose annotation using GsonBuilder.excludeFieldsWithoutExposeAnnotation(). |
| NA | jackson.annotation.JsonRootName; | JsonRootName(value="abc") public class ClassName {} | NA | javax.xml.bind.annotation.XmlElement | XmlRootElement public class ClassName {} |
References:
https://www.baeldung.com/jackson-vs-gson
http://websystique.com/java/json/gson-json-annotations-example/
https://www.tutorialspoint.com/gson/gson_tree_model.htm
https://google.github.io/gson/apidocs/index.html?com/google/gson/class-use/JsonElement.html
https://www.baeldung.com/gson-deserialization-guide
http://websystique.com/java/json/gson-tree-model-example/