Learn how to create and manipulate JSON arrays in Java.

Understand how to create and manipulate JSON arrays in Java

In Java development, processing and manipulating JSON (JavaScript Object Notation) arrays is a very common task . JSON is a lightweight data exchange format that is often used for front-end and back-end data transmission and storage. A JSON array consists of an ordered set of values ​​and can contain elements of any type. This article will introduce how to create and operate JSON arrays in Java, and provide code examples to help readers better understand and apply it.

1. Create JSON array

There are many ways to create a JSON array in Java. You can use third-party libraries, such as Jackson, Gson, etc., or you can use Java's own JSON library (org.json).

The sample code for using the org.json library to create a JSON array is as follows:

import org.json.JSONArray;
import org.json.JSONException;

public class JsonArrayExample {
    public static void main(String[] args) {
        JSONArray jsonArray = new JSONArray();

        try {
            jsonArray.put("Apple");
            jsonArray.put("Banana");
            jsonArray.put("Orange");
        } catch (JSONException e) {
            e.printStackTrace();
        }

        System.out.println(jsonArray);
    }
}

Running the above code will output the string representation of the JSON array: ["Apple", "Banana", " Orange"].

2. Operation JSON Array

After creating a JSON array, we can perform various operations on it, such as accessing elements, adding, deleting, modifying, etc.

import org.json.JSONArray;
import org.json.JSONException;

public class JsonArrayExample {
    public static void main(String[] args) {
        JSONArray jsonArray = new JSONArray();

        try {
            jsonArray.put("Apple");
            jsonArray.put("Banana");
            jsonArray.put("Orange");
        } catch (JSONException e) {
            e.printStackTrace();
        }

        // 访问元素
        System.out.println(jsonArray.get(0));
        // 输出：Apple

        // 添加元素
        jsonArray.put("Mango");
        System.out.println(jsonArray);
        // 输出：["Apple", "Banana", "Orange", "Mango"]

        // 删除元素
        jsonArray.remove(2);
        System.out.println(jsonArray);
        // 输出：["Apple", "Banana", "Mango"]

        // 修改元素
        jsonArray.put(0, "Watermelon");
        System.out.println(jsonArray);
        // 输出：["Watermelon", "Banana", "Mango"]
    }
}

Through the above code, we can see the results of various operations on the array on the console.

3. Parsing and generating JSON arrays

In addition to manually creating and manipulating JSON arrays, we can also obtain JSON arrays by parsing strings or generating objects.

The sample code for parsing a JSON array is as follows:

import org.json.JSONArray;
import org.json.JSONException;

public class JsonArrayExample {
    public static void main(String[] args) {
        String jsonString = "["Apple", "Banana", "Orange"]";

        try {
            JSONArray jsonArray = new JSONArray(jsonString);
            System.out.println(jsonArray);
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
}

The output result is: ["Apple", "Banana", "Orange"].

The sample code to generate a JSON array is as follows:

import org.json.JSONArray;

public class JsonArrayExample {
    public static void main(String[] args) {
        JSONArray jsonArray = new JSONArray();

        jsonArray.put("Apple");
        jsonArray.put("Banana");
        jsonArray.put("Orange");

        System.out.println(jsonArray.toString());
    }
}

The output result is: ["Apple", "Banana", "Orange"].

Through the above example code, we can parse a JSON array from a string, or convert data in Java into a JSON array.

Summary

This article introduces how to create and manipulate JSON arrays in Java and provides corresponding code examples. Understanding how to manipulate JSON arrays is very important for data exchange and processing. I hope readers will have a deeper understanding of JSON arrays through the introduction and examples of this article, and be able to use them flexibly in actual development.

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