Learn from the technical principles of JSON in Java in the Java class library
Learn from the technical principles of JSON in Java in the Java class library
Introduction:
JSON (JavaScript Object Notation) is a lightweight data exchange format that is widely used in data transmission and storage between Web applications.The JSON In Java technology in the Java class library enables developers to analyze and generate JSON data in the Java program and interact with other systems.This article will explore the technical principles of JSON in Java, including related programming code and configuration.
1. The concept of json in java
JSON is a text format that uses simple key values to represent data and has the characteristics of easy reading and writing.JSON in Java is a technology that analyzes and generates JSON data in the Java program.The Java class library provides many convenient classes and methods for operating JSON data.
2. The basic structure of JSON
JSON data consists of a key value pair, and use a colon to separate between the key and the value. The key value is separated by a comma.The value in JSON can be string, numbers, Boolean values, objects, array or null.
3. JSON in Java use
The use of JSON In Java technology in Java can achieve the following functions:
-Cap the java object to a json format string: Use the method in the JSON class library to encode the Java object as a JSON string.
-Prove JSON string as Java object: Use the method in the JSON class library to analyze the JSON string as the Java object.
-Prip JSON objects in the Java program: Use the method provided by the class library to directly operate the JSON object in the Java program, such as adding, deleting or modifying key values pairs.
-Chide JSON array: Convert JSON array to Java array or collection, or convert the Java array or collection to the JSON array.
4. JSON in Java class library
In the Java class library, there are many popular JSON libraries to choose from, such as GSON, Jackson and JSON.SIMPLE.These class libraries provide APIs and functions for different needs, which can be selected and used according to specific needs.
5. JSON in Java code example
Below is a simple example of using the GSON class library. Convert the Java object to a string in JSON format and parsing back to the code of the Java object:
import com.google.gson.Gson;
public class JsonExample {
public static void main(String[] args) {
// Create a Java object
Person person = new Person("John", 25);
// Convert java objects to json string
Gson gson = new Gson();
String json = gson.toJson(person);
System.out.println ("JSON string:" + json);
// Analyze the JSON string as Java object
Person parsedPerson = gson.fromJson(json, Person.class);
System.out.println ("Java object after analysis:" + Parsederson);
}
}
class Person {
private String name;
private int age;
public Person(String name, int age) {
this.name = name;
this.age = age;
}
// omit the getter and setter method
@Override
public String toString() {
return "Person [name=" + name + ", age=" + age + "]";
}
}
In the above example, we use the GSON class library to convert Person objects into JSON string, and use the same class library to analyze the JSON string into a new Person object.
6. Json in java related configuration
When using JSON In Java technology, some configurations can be performed according to actual needs, such as the date format, the order of attributes, etc.Different JSON class libraries may have different configuration methods. Please configure accordingly according to the document of the selected library.
in conclusion:
Through the JSON In Java technology in the Java class library, developers can easily analyze and generate JSON data in the Java program.This article introduces the basic structure of JSON, how to use JSON in Java, and code examples. I hope to help readers deeply understand the technical principles of JSON in Java.In actual development, you can choose a suitable JSON class library according to specific needs, and perform relevant configuration to meet the needs.
