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In a computer system, the binary number is expressed in the binary numeral system while the decimal number is in the decimal numeral system. The binary number is in base 2 while the decimal number is in base 10. Examples of decimal numbers and their corresponding binary numbers are as follows: Decimal Number ... Read More
Gson is a library in the Java that is mainly used for converting Java objects to JSON and vice versa. By default, the Gson object does not serialize the fields with null values to JSON. If a field in a Java object is null, Gson excludes it.Serializing a Null Field Using Gson We can force Gson to serialize null values via the GsonBuilder class. We need to call the serializeNulls() method on the GsonBuilder instance before creating the Gson object. Once serializeNulls() has been called, the Gson instance created by the GsonBuilder can include null fields in the serialized JSON. ... Read More
Deserialization is the process of converting a JSON string into a Java object. In this example, we will learn how to deserialize a JSON string into an existing object in Java. There are libraries available in Java that can help us to deserialize a JSON string into an existing object. Some of the popular libraries are: Using Gson Using Jackson Using Flexjson Let's learn how to use each of these libraries to deserialize a JSON string into an existing object in Java. Deserializing JSON Object Using ... Read More
Serialization is the process where we convert an object into a format that can be easily stored or transmitted and later reconstructed. The given task is to serialize an array of objects using Flexjson in Java. Serializing an Array of Objects Using Flexjson Flexjson is a lightweight Java library for serializing and deserializing java beans, maps, arrays, and collections in JSON format. We can also deserialize a JSON string to an existing object using the deserializeInto() method of the JSONDeserializer class, this method deserializes the given input into the existing object target. The values in the JSON input can overwrite ... Read More
Gson is a Java library which is developed by Google and used to convert Java objects into JSON and vice versa. It is mostly used in applications where data can be exchanged in JSON format. There are two useful methods in Gson that we are going to discuss in this article. These methods are fromJson() and toJson(). The fromJson() Method The fromJson() method is used to convert a JSON string into a Java object. It takes two parameters: the JSON string and the class type of the object you want to create. Here is the syntax of the fromJson() method: ... Read More
Serializing a Map in Java is the process of converting a Map object into a format that can be easily stored or transmitted, such as JSON or XML. We will use the Flexjson library to serialize a map in Java. We can serialize a Map using the serialize() method of the JSONSerializer class, which performs a shallow serialization of the target instance. Example of Serializing a Map We will take a map and see the output after serialization. Map map = new HashMap(); map.put("name", "Ansh"); map.put("age", "23"); map.put("city", "Mumbai"); map.put("country", "India"); After serialization, the map will look like this: {"name":"Ansh", ... Read More
Parsing a JSON without duplicate keys means converting a JSON string into a Java object. But we need to keep in mind that the JSON string should not have duplicate keys. Gson: Parsing a JSON Without Duplicate Keys We can use the Gson library to parse a JSON without duplicate keys in Java. It is developed by Google and used for converting Java objects into JSON and vice versa. By default, Gson does not allow duplicate keys in JSON. If a JSON string has duplicate keys, Gson will throw a JsonSyntaxException. We will use the methods fromJson() and toJson() to achieve ... Read More
JSON is a format for storing and exchanging data. It is easily readable and also easy to parse. Creating JSON Using Java JsonGenerator In Java, we can create a JSON object using the JsonGenerator class. JsonGenerator is class in the javax.json.stream package that is used to create JSON data. It provides methods to write JSON objects, arrays, and values. To use the JsonGenerator class, we need to add the javax.json library to our project. If you are using Maven, add this to your pom.xml file: javax.json javax.json-api 1.1.4 If you are not using Maven, you can download ... Read More
To create a JSON using the Jackson Tree Model in Java, we can use the ObjectMapper class. The ObjectMapper class is part of the Jackson library and is used to convert Java objects to JSON and vice versa. To use the Jackson library, we need to add it to our project. If you are using Maven, add this to your pom.xml file: com.fasterxml.jackson.core jackson-databind 2.13.0 If you are not using Maven, you can download the jar file from here. Creating a JSON using Jackson Tree Model in ... Read More
Enabling version support means that the Gson library will be able to handle multiple versions of the same class. We use this when we have a class that has been modified and we want to be able to deserialize JSON data that was created using an older version of the class. Enabling Versioning Support in Java Gson Library The Gson library provides a simple versioning system for the Java objects that it reads and writes, and also provides an annotation named @Since for the versioning concept @Since(versionnumber). We can create a Gson instance with versioning using the GsonBuilder().setVersion() method. If ... Read More