Mapper class in java. You will also learn about Map Methods and Implementation.

Mapper class in java This guide explores the ModelMapper library in Java, demonstrating how to simplify object mapping and conversion between different data models effectively. Jul 7, 2021 · A MapStruct mapper is an interface or an abstract class annotated with @Mapper. Jul 31, 2025 · Learn how to use multiple source objects with MapStruct. The Jackson ObjectMapper can parse JSON from a string, stream or file, and create a Java object or object graph representing the parsed JSON. class); But I can't work out how to get the mapper to convert the List of Things to List of ThingDTOs. Let’s start with a basic mapping example to see how it works. Typically, the generated code will loop over the source collection, convert each element to the target type, and include each Oct 11, 2025 · Learn what Java Map is, how it works, and when to use it. Each key must be unique, but values can be duplicated. or any user-defined type) to be the parameter to methods, class, or interface. Some of the cool features of ModelMapper are: Intelligent Refactoring Safe Feb 15, 2023 · In this article, I’m gonna explain how to implement a custom mapper util class in Java without using third party libraries like MapStruct. When dealing with different data models, such as transferring data between a database and a Java application or converting data from one format to another, mappers act as a bridge. Mapper implementations can access the Configuration for the job via the JobContext. Dec 29, 2012 · Take a look at Dozer and modelmapper. map(request, ResponseTo. Oct 18, 2016 · In this tutorial, we’ll explore the use of MapStruct, which is, simply put, a Java Bean mapper. What is Generic Map and how is it different from the term HashMap? The term generic simply is the idea of allowing the type (Integer, Double, String, etc. The Hadoop Map-Reduce framework spawns one map task for each InputSplit generated by the InputFormat for the job. Nov 13, 2024 · Object Mapper is a powerful tool in Java programming that simplifies the process of mapping between two different data structures. It uses a convention based approach while providing a simple refactoring safe API for handling specific use cases. Now I need to create the Map but keys the values of the attributes. Aug 20, 2022 · Learn to use Jackson 2. Mar 17, 2025 · ObjectMapper is one of the most important class available in the Jackson library. Whether implemented manually or with libraries like MapStruct, they simplify data transformations and reduce coupling between application layers. . Feb 1, 2024 · The Jackson ObjectMapper class (com. We also saw some detailed examples of alternative configurations. Jan 16, 2024 · MapStruct is a library that helps us to minimize boilerplate code when dealing with Java Beans mapping. Jun 6, 2018 · This article compares the performance of popular Java mapping frameworks to help developers choose the best one for their needs. Start learning about map interface in java now! Feb 29, 2024 · Learn how to configure the serialization and deserialization options for Jackson using Spring Boot. Jun 21, 2024 · 1. JSON is a widely used file format used for storing and transferring property-value pairs of classes. It provides an easy-to-use API for performing object-to-object mapping and can handle complex mappings with nested objects. It contains basic fields like firstName, lastName, and age. Map interface. core. 2 Implementation of Row Mapper This class maps a database record to the java model object. map(source, SourceDTO. Like this public <T> void deSerialize (Class<T> clazz { ObjectMapper mapper = new ObjectMapper (); mapper. We will understand the mappers in details in the example. Oct 27, 2025 · Hierarchy of Map It is part of the Java Collections Framework, and its key implementation classes include HashMap, LinkedHashMap, TreeMap, and Hashtable. x to read JSON into Java object and convert Java object to JSON string. In this tutorial, we’ll explore three different approaches to converting an Object to a Map in Java May 20, 2016 · Mapper is the base class which is used to implement the Map tasks in Hadoop MapReduce. Jul 26, 2025 · Simplify Java Bean Mapping in Spring Boot with MapStruct’s @Mapper When building Java applications with Spring Boot, data transformation between layers is a common task. java. A Map is useful when you want to associate a key (like a name or ID) with a value (like an age or description). A HashMap can store many different combinations, such as: String keys and Integer values String keys and String values Jun 19, 2021 · Person person = mapper. Jul 16, 2024 · Today, let’s delve into the concept of an Object Mapper, a vital tool in Java programming for converting between various object formats, especially for JSON processing. util. I have a Java class with instance fields (and matching setter methods) that match the column names of a SQL database table. It is highly versatile and can handle various data formats and types. Jun 15, 2020 · In this example, we will learn about the ObjectMapper class from Jackson and its capabilities to serialize POJOs (Plain Old Java Objects) into JSON strings and deserialize JSON strings back into Java objects, with some examples. Sep 24, 2018 · TL;DR I want to use modelMapper in a way that I map from AbstractParent to AbstractParentDTO and later in the ModelMapper-Config call the specific mappers for each Sub-class and then skip the rest Java Map Interface The Map interface is a part of the Java Collections Framework and is used to store key-value pairs. class); No need to convert into JSON string or something else; direct conversion does much faster. Sep 24, 2018 · TL;DR I want to use modelMapper in a way that I map from AbstractParent to AbstractParentDTO and later in the ModelMapper-Config call the specific mappers for each Sub-class and then skip the rest Jul 12, 2019 · 4 Although there is strictly speaking nothing incorrect about calling a service from a mapper, it does add dependencies to the mapper, which is usually a pure object (Plain Old Java Object, POJO) that simply converts an object of one type to another. Oct 3, 2025 · A Mapper is a user-defined Java class that takes input splits (chunks of data from HDFS), processes each record and emits intermediate key-value pairs. In Java, elements of Map are stored in key/value pairs. The Jan 8, 2024 · Converting an Object to a Map can be useful in Java when we seek to transform an object’s properties into a key-value representation. class); This is safe as ObjectMapper is thread-safe after configuration. INSTANCE. From the documentation, I think I need to create a mapper class that extends PropertyMap but I can't work out how to configure it. Feb 22, 2014 · It is a JPA based Java object mapper which helps with many of the tedious SQL and JDBC ResultSet related tasks, but without all the complexity an ORM framework comes with. This interface takes the place of the Dictionary class, which was a totally abstract class rather than an interface. 1 Entity Class The User class represents the source entity that we want to map. With MapStruct, we only need to create the interface, and the library will automatically create a concrete implementation during compile time. databind. Oct 27, 2025 · A HashMap is a part of Java’s Collection Framework and implements the Map interface. This involves using generic types in Java as a solution to convert different types of data from one list to another. An alternative is to pass the required information into the mapper as a parameter. Oct 22, 2018 · Use the mapper for the base class to map the child class Asked 6 years, 9 months ago Modified 6 years, 9 months ago Viewed 13k times Apr 3, 2013 · For base JSON functionality, you need to add the following jars to your project's libraries: jackson-mapper-asl and jackson-core-asl Choose the version your project needs. It is widely used for mapping data between different Java beans, typically in the context of transferring data between layers in an application. Model Mapper An object that maps keys to values. It is part of the java. 2. It stores elements in key-value pairs, where, Keys are unique. Apr 1, 2025 · This Comprehensive Java Map Tutorial Covers how to Create, Initialize and Iterate through Maps. Aug 2, 2023 · Learn how to choose between automatic mappers ModelMapper and MapStruct to improve productivity and maintainability, as well as reduce errors in data mapping. Jan 18, 2024 · In general, mapping collections with MapStruct works the same way as for simple types. A mapper is a function or a class responsible for converting an object of one type into an object of another type. Oct 12, 2018 · The attribute values for the above mentioned class were generated by mapping to properties file and by using spring annotation @ConfigurationProperties. getMapper(Class) cdi: the generated mapper is an application-scoped CDI bean and can be retrieved via @Inject spring: the generated mapper is a Spring bean and can be retrieved via @Autowired jsr330: the generated mapper is annotated with @javax. This is a typical Java POJO (Plain Old Java Object) with constructors, getters, and setters that make it compatible with MapStruct’s mapping engine. In this tutorial, we’ll learn how to construct complex mappers built with simple ones and map nested structures. Sep 17, 2025 · As well known, Java erases generic type information during compilation, but we can take advantage of the power of anonymous inner classes to preserve the type information during compile time. In this MyBatis tutorial, explore MyBatis Mapper classes for database interactions, including core annotations + variable injection for CRUD operations. public class UserRowMapper implements RowMapper&lt;UserData&gt; { @Override public UserData mapRow(ResultSet resultSet, int line) throws SQLException { Apr 19, 2016 · modelMapper. This example shows how to use mapper to build Data Access Objects ( DAOs ) to access Apache Cassandra™ in a Java application. I would like to elegantly fetch a row from the table (into a ResultSet) and map it to an instance of this class. inject. Nov 12, 2025 · In the Java ecosystem, a mapper plays a crucial role in simplifying the data transformation process. util package that represents a mapping between key and value. The goal of ModelMapper is to make object mapping easy, by automatically determining how one object model maps to another, based on conventions. class); Apart from jackson's ObjectMapper there are DozerBeanMapper, BeanUtils, google's Gson can be used for same purpose. Here’s why: Tedious: Writing line after line of code to move data between objects can be slow and boring. Parsing JSON into Java objects is also referred to as to deserialize Java objects from JSON. This can be very helpful, especially when dealing with data manipulation, serialization, or when we need to pass object data to other parts of our program. Simplifying it Jun 7, 2016 · Classes can be mapped 1 on 1 by defining in the mapper xml file attribute wildcard="true". May 11, 2024 · In this article, we detailed simplifying the conversion from Entity to DTO, and from DTO to Entity in a Spring REST API, by using the model mapper library instead of writing these conversions by hand. Maven Dependencies Feb 17, 2023 · This beginner's guide to object mapping with ModelMapper in Java shows you how to easily map data between objects with different structures. Jul 23, 2025 · To overcome these problems DTO came into the picture, with DTO we can choose which fields we need to expose to the web layer. jackson. readValue(jsonString, JsonSimple. Apr 21, 2024 · In Java, an object mapper is a tool used to convert data between incompatible type systems, such as converting objects to and from database rows, JSON documents, or XML files. Mar 26, 2025 · 5. Caveat: As @StaxMan points out in the answer comments, this does NOT guarantee against further (re)configuration on the returned singleton. Understanding how to leverage MapStruct for custom mappings enhances code reusability and maintainability, making your applications more scalable and Apr 30, 2020 · In this tutorial, we’ll explain how to map lists of different element types using the ModelMapper framework. getMapper() ? Exmaple: @Mapper(componentModel = &quot;spring&quot;, nullValueCheckStrategy = Jan 12, 2025 · MapStruct is a powerful Java annotation processor that simplifies the mapping between Java bean types. It becomes particularly… Jun 8, 2022 · Whenever we annotate a Mapper method with the @Mapper annotation, it creates an implementation class with the same mapper methods having all the setters and getters auto-generated. What is an Object Mapper Oct 27, 2023 · The method accepts a wide variety of data sources, which we'll go through in the upcoming sections. Oct 22, 2018 · Use the mapper for the base class to map the child class Asked 6 years, 9 months ago Modified 6 years, 9 months ago Viewed 13k times Learn how to implement the Mapper in Hadoop MapReduce, a powerful distributed data processing framework. One powerful feature of MapStruct is the use of expression clauses to leverage existing mappers within mappings. Discover the key concepts and step-by-step guide to leverage the Mapper in your Hadoop projects. Oct 4, 2018 · 3. Nov 4, 2024 · Using MapStruct Expression in Spring Boot allows us to define custom logic within our mapping methods. 1. Basically, we have to create a simple interface or abstract class, and declare the mapping methods. It is used to read and write JSON data. ObjectMapper class ObjectMapper provides functionality for reading and writing JSON, either to and from basic POJOs (Plain Old Java Objects), or to and from a general-purpose JSON Tree Model (JsonNode), as well as related functionality for performing conversions. Explore the Data Mapper pattern in Java, which decouples database operations from business logic. It is responsible for reading data May 11, 2024 · In this tutorial, we’ll learn how to use a custom mapper with the MapStruct library. getObjectMapper(); JsonSimple jsonSimple = mapper. Jackson provides the abstract class TypeReference to obtain the type information from the derivated subclasses: public abstract class TypeReference <T> { Jan 19, 2024 · In Java, entities and DTOs are two different types of classes often used together. Where To Start? The first step to getting our hands dirty with ObjectMapper and Jackson data binding is to get the libraries and add them to the classpath. Jul 23, 2025 · This article explains how to map a dynamic JSON object field in Jackson using Java, providing a step-by-step guide for developers. ModelMapper is a maven library which is used for the conversion of entities object to DTO and vice-versa. The Jackson ObjectMapper can Jul 23, 2025 · Step 5: Create an implementation class for Dao Interface In this step, we will create an implementation class StudentDaoImpl. default: the mapper uses no component model, instances are typically retrieved via Mappers. class, MainDishMixin. Implementations of this interface perform the actual work of mapping each row to a result object. Object Mapping with MapStruct Imagine juggling data in your Java application, constantly converting information between different formats. Jan 8, 2024 · Learn how to serialize Java objects to XML and deserialize them back using the Jackson library in this concise tutorial. SQLExceptions if any thrown will be caught and handled by the calling JdbcTemplate. The driver provides a Jan 8, 2024 · Learn three ways to deserialize nested JSON values in Java using the Jackson library. Jan 8, 2024 · In this quick tutorial, we’ll look at the serialization and deserialization of Java maps using Jackson. Connecting Both Sides Next, the layer that ties both classes uses a mapper component to pass the data from one side to the other and vice versa. The Jun 26, 2024 · In modern Java applications, converting different object types — such as entities and data transfer objects (DTOs) — is a common but often tedious task. In this tutorial, we will learn how to use the ModelMapper library to map the JPA entity into DTO and vice versa. Sep 16, 2021 · In this article, we'll go through many examples of using MapStruct for Advanced Java Mapping, exception handling and MapStruct annotations. In this tutorial, we will learn more about this class. Apr 22, 2025 · 2. In this advanced tutorial, we will explore several advanced features of MapStruct, such as mapping from multiple sources to a target object, using Java expressions in mappings and much more! Prerequisites Before diving into the examples, ensure you have checked this introduction article to In this tutorial, we will learn about the Java Map interface and its methods. ModelMapper is an intelligent, refactoring safe object mapping library that automatically maps objects to each other. util package and implements the Map interface. and Values can be duplicated. Mar 11, 2025 · In the interface, we must import the classes used in the Java code embedded in the expression attribute of the @Mapping annotation over the carToCarDto () method. addMixIn(MainDish. Java HashMap A HashMap stores items in key/value pairs, where each key maps to a specific value. Add the following code to it: Want to master Spring Framework ? MapStruct is a code generator that simplifies the implementation of mappings between Java bean types based on a convention over configuration approach. Aug 4, 2016 · Dozer is a Java Bean to Java Bean mapper that copies data from one object to another, attribute by attribute, supports mapping between attribute names, does type conversion, and many other things. This means that it will automatically try to map every property in the two objects. MapStruct is a Java annotation processor for the generation of type-safe bean mapping classes. Jun 4, 2021 · A brief about advanced mapping concepts to configure special behavior of MapStruct and integration with Dependency Injection Frameworks like CDI and Spring. Learn to use Jackson ObjectMapper class. May 5, 2024 · Learn how to use the Mapstruct mappers with inherited Java bean classes. Instead of accessing elements by an index (like with ArrayList), you use a key to retrieve its associated value. How can I reuse this mapper in another mapper which is in another class? I have below as model @ May 21, 2023 · Java object mapping is an essential task when working with data-driven applications, as it allows us to convert between different data structures and simplify data access and manipulation. This special annotation is used by the MapStruct code generator to automatically generate a working implementation of this Java file at build-time. readValue (jsonString, new TypeReference<Json<T>> () {}); } What is it? MapStruct is a code generator that greatly simplifies the implementation of mappings between Java bean types based on a convention over configuration approach. Maps are the individual tasks which run before reducers and transforms the inputs into a set of output values. Sep 22, 2019 · Then we register the MixIn in our ObjectMapper class using mapper. The Map interface provides three collection views, which allow a map's contents to be viewed as a set of keys, collection of values, or set of key-value mappings. It implements java. Convert JSON String to Java Object (POJO) The simplest form of input is a String - or rather, JSON-formatted Strings: <T> T readValue(String content, Class<T> valueType) Consider the following HealthWorker class in a Health Management System: public class HealthWorker { private int id; private What if I dont know what class it is until runtime? I will get the class as a parameter during runtime. springframework. 2. Feb 24, 2016 · ObjectMapper mapper = Mapper. Jul 23, 2025 · ModelMapper is an intelligent, refactoring safe object mapping library that automatically maps objects to each other. The MapStruct library is used for mapping between Java bean types. We can write expressions in the Mapper interface inside the @Mapping annotation with the expression “—-” attribute to handle specific conversion scenarios logic such as mapping different field types between DTO and Entity classes. May 11, 2024 · In this article, we explained how to customize class-to-class mappings with property mappers in ModelMapper. Jul 31, 2018 · A complete set of examples for serialization and deserialization with Java and JSON for the most common use cases. Aug 28, 2019 · final ObjectMapper mapper = new ObjectMapper(); // jackson's objectmapper final MyPojo pojo = mapper. Aug 14, 2016 · Hi This is my Row Mapper class. I know that Dozer integrates with Spring. This allows you to call one mapper from another during the mapping process smoothly. To understand more about the Jackson library in general, the Jackson Tutorial is a good place to start. Jul 16, 2024 · Map in java is an interface available in java. These pairs are then shuffled and sorted before being passed to the Reducer (or directly stored in case of a Map-only job). synchronizedMap(new HashMap()); The iterators returned by all of this class's "collection view methods" are fail-fast: if the map is structurally modified at any time after the iterator is created, in any way except through the iterator's own remove method, the iterator will throw a ConcurrentModificationException. Oct 16, 2025 · Converting a `Map` to a data class can simplify data handling, improve code readability, and make it easier to work with structured data. class); and we are done! Then the test will pass and we achieved what we wanted: without directly modifying the target class, we managed to successfully deserialize it into a Java object. The Introduction ModelMapper is a Java library that simplifies the process of mapping between different object models, such as Data Transfer Objects (DTOs) and entities. Common classes that implement Map: HashMap - fast and unordered TreeMap - sorted by key LinkedHashMap This guide explores the ModelMapper library in Java, demonstrating how to simplify object mapping and conversion between different data models effectively. Common classes that implement Map: HashMap - fast and unordered TreeMap - sorted by key LinkedHashMap Aug 12, 2022 · Discover how to use Jackson library to map JSON objects to Java objects and vice versa, including dynamic objects and annotations for customizing the process. synchronizedMap Jan 29, 2024 · In simple terms “mapper” is often associated with the concept of mapping between different data structures or objects. RowMapper<T> interface is used by JdbcTemplate for mapping rows of a ResultSet on a per-row basis. A given input pair may map to zero or many output pairs. ObjectMapper) is the simplest way to parse JSON with Jackson in Java. This class implements the StudentDao interface and provides the definition to the getAllStudentDetails () method of the StudentDao interface. I need to inject a spring service class in the generated mapper implementation, so that I can use it via @Mapping(target="x", expression="java(myservice. Jul 23, 2025 · HashMap is a part of Java since Java 1. By using a custom mapper with MapStruct, we can customize the default mapping methods. I already have mapper for one of the object. Nov 17, 2021 · I have a mapper that, for a particular attribute of the target class, needs to choose one from a list of objects inside the source object, and map it using a differente mapper class. Keys are unique values associated with individual values. This tutorial will demonstrate how to use ModelMapper in a Spring Boot application to handle CRUD (Create Dec 8, 2012 · In this tutorial, we are implementing RowMapper class to map domain objects. It is a simple-to-use class that provides us with a lot of different options to parse JSON. map-interface Implemented Classes of Map Interafe HashMap: Stores key-value pairs using hashing for fast access, insertion, and deletion. Named and @Singleton, and can be retrieved via Aug 6, 2021 · Jackson ObjectMapper The Jackson ObjectMapper class is used to map objects to JSON or JSON to objects. These output values are the intermediate values which act as the input to the Reduce task. This API contains functions that automatically map between two Java Beans. Manually writing mapping code can lead Mar 4, 2020 · I would like to mapping a model object to dto model. Introduction to MapStruct MapStruct is a Java annotation processor that generates type-safe and efficient mappers for object mappings. An object that maps keys to values. Sep 9, 2021 · I am currently using mapstruct to map data between entities and DTOs, inside a mapper I need to instantiate a class using @Autowired, inside the class I need to instantiate I have a method that loads data into the cache, when I try to do the following: @ Autowired RepositoryImpl repository; IntelliJ tells me: The variable 'repository' may not In this tutorial, we will learn about the Java Map interface and its methods. This manual object mapping can be a real headache. MapStruct allows developers to create high-performance mappers with minimal boilerplate code. Based on our declarations, MapStruct will generate the mapping code automatically. This tutorial explores how to implement custom mappers with MapStruct, a powerful code generator that simplifies the mapping between Java bean types. Includes examples, key methods, and best practices for working with Map in Java. This blog post will guide you through the process of converting a `Map` into a data class in Java, covering core concepts, typical usage scenarios, common pitfalls, and best practices. Jul 25, 2019 · You should use the spring componentModel in mapper class @Mapper (componentModel = "spring") and the expected dependency configuration of annotation processors which is described on the mapstruct site dependency config Provides information on MyBatis-Spring integration, focusing on mapper configuration and usage in a Spring application. How MapStruct Works Jan 8, 2024 · Learn how to serialize Java objects to XML and deserialize them back using the Jackson library in this concise tutorial. fasterxml. The generated mapping code uses plain method invocations and thus is fast, type-safe and easy to understand. Mapper (and ObjectReader s, ObjectWriter s it constructs) will use instances of JsonParser and JsonGenerator for implementing actual reading/writing of JSON. Basic Mapping Example Let’s start with a very basic mapping example. We then use this class to write fetch methods that return custom model objects. Feb 25, 2024 · Using DTO (Data Transfer Object) Projection — Mapping Entities to DTOs and vice versa in Java Spring Boot DTO projection allows us to define a subset of attributes that we want to expose in our … Oct 27, 2025 · A HashMap is a part of Java’s Collection Framework and implements the Map interface. convertValue(map, MyPojo. Data Jun 25, 2024 · ObjectMapper is a class provided by the Jackson library in Java, used for converting Java objects to JSON and vice versa. We’ll illustrate how to serialize and deserialize Map<String, String>, Map<Object, String>, and Map<Object, Object> to and from JSON-formatted Strings. ObjectMapper also acts as a factory for more advanced ObjectReader and ObjectWriter classes. First of all, guys, you should have basic knowledge Dec 11, 2024 · Mapper classes in Java are indispensable for building scalable and maintainable applications. In Dozer your code will look something like this: ResponseTo response = mapper. Further, the Java code uses Arrays#asList () method to create a List object with two elements of type ManufacturingPlantDto class. A map cannot contain duplicate keys; each key can map to at most one value. Map m = Collections. Apr 15, 2022 · I want to use the mapper, in another mapper in the named method, how can I do this without using Mappers. This normally happens in the presentation layer: @RestController @RequestMapping("/users") class UserController { private UserService userService; private RoleService roleService; private Mapper Java Map Interface The Map interface is a part of the Java Collections Framework and is used to store key-value pairs. Learn how to implement and utilize this pattern to enhance maintainability and flexibility in your Java applications. HashMap is not thread-safe, to make it synchronized, use Collections. Any pointers to the relevant documentation would be welcome The Java DataStax Driver comes with an object mapper that removes boilerplate of writing queries and lets you focus on your application objects. They are both excellent tools for mapping one object to another. Jul 25, 2019 · You should use the spring componentModel in mapper class @Mapper (componentModel = "spring") and the expected dependency configuration of annotation processors which is described on the mapstruct site dependency config Overview The org. Jan 8, 2024 · This tutorial focuses on understanding the Jackson ObjectMapper class and how to serialize Java objects into JSON and deserialize JSON string into Java objects. findById(id))")" Is this applicable in Jan 8, 2024 · Learn three ways to deserialize nested JSON values in Java using the Jackson library. Reading Using ObjectMapper in Java We can Jul 31, 2018 · A complete set of examples for serialization and deserialization with Java and JSON for the most common use cases. Internally uses Hashing, hence allows efficient key-based retrieval, insertion, and removal with an average of O (1) time. Sep 17, 2024 · The @Mapper and @Mapping annotations are part of MapStruct, a code generator that simplifies the process of mapping between Java objects. class); It's very powerful and very easy to use. You will also learn about Map Methods and Implementation. jdbc. getConfiguration(). 3. convertValue(map, Person. MapStruct generates mapping code at compile time, ensuring high performance and type safety. It generates mappers using only provided interfaces. The Nov 20, 2023 · Object mapping, the process of transforming data from one object to another, is a common task in Java development. Entities are used to represent data in the database… Oct 21, 2024 · Learn how to perform DTO to Entity mapping with different field types in Spring Boot using Manual mapping, MapStruct and ModelMapper for efficient data conversion. Learn how to use ModelMapper to simplify the object Introduction ObjectMapper is the main actor class of Jackson library. vntbklq msx rvszvqyw qogmidk hgqcvv vjk wnpqn acdygb ehkdxg aewg ztwiuxoo kskvbo xbduua cbwbdg wuycgw