Hi Devs, I'm relatively new to the world of backend development, and I'm currently working on a Java project using the Spring Boot framework. My application involves a lot of JSON data manipulation. Here's what I'm up to:

I fetch data from some APIs, manipulate it according to my application's needs, and provide that data through controllers. JSON plays a central role in this process.

As a beginner in this field, I'm looking for advice from experienced developers. Which JSON library have you found to offer the best developer experience when working in Java, especially within a Spring Boot project?

In my case, what factors should I prioritize for a smooth development experience considering the heavy JSON manipulation I'm doing?

I have knowledge of Java, and I have made many programs with this language. But now, I want to learn how to work with JSON files. I use Maven and have heard that there are many libraries for JSON. What is the best and easiest one?

Minimal, standard-first JSON writer and parser. One single Java file, 1k LoC, no dependencies.

Background

I often write small Java tools (CLI, Gradle plugins, scripts) that need to read/write JSON. I really don't want to use JSON libraries that larger than my codebase, so I wrote json4j.

Usage

You can use as dependency:

implementation("io.github.danielliu1123:json4j:+")

or use as source code, just copy Json.java into your codebase:

mkdir -p json && curl -L -o json/Json.java https://raw.githubusercontent.com/DanielLiu1123/json4j/refs/heads/main/json4j/src/main/java/json/Json.java

There are only two APIs:

record Point(int x, int y) {}
    
// 1) Write JSON
Point point = new Point(1, 2);
String json = Json.stringify(point);
// -> {"x":1,"y":2}
    
// 2) Read JSON
    
// 2.1) Simple type
String json = "{\"x\":1,\"y\":2}";
Point point = Json.parse(jsonString, Point.class);
// -> Point{x=1, y=2}
    
// 2.2) Generic type
String json = "[{\"x\":1,\"y\":2},{\"x\":3,\"y\":4}]";
List<Point> points = Json.parse(jsonString, new Json.Type<List<Point>>() {});
// -> [Point{x=1, y=2}, Point{x=3, y=4}]

That's all!

Link

Repo: https://github.com/DanielLiu1123/json4j