Pros of google/gson

• Simplicity: Gson provides a straightforward and easy-to-use API for serializing and deserializing JSON data.
• Flexibility: Gson supports a wide range of data types and can handle complex JSON structures with ease.
• Performance: Gson is generally faster than the JSON-java library, especially for large JSON payloads.

Cons of google/gson

• Dependency Management: Gson is a standalone library, which means it needs to be included as a dependency in your project, adding to the overall project size.
• Limited Customization: Gson has fewer customization options compared to JSON-java, which may limit its flexibility in certain use cases.
• Lack of Streaming API: Gson does not provide a streaming API, which can be useful for processing large JSON datasets.

Code Comparison

JSON-java:

JSONObject obj = new JSONObject();
obj.put("name", "John Doe");
obj.put("age", 30);
obj.put("email", "john.doe@example.com");

Gson:

Gson gson = new Gson();
JsonObject obj = new JsonObject();
obj.addProperty("name", "John Doe");
obj.addProperty("age", 30);
obj.addProperty("email", "john.doe@example.com");

Pros of Jackson

• Supports a wider range of JSON features, including advanced data types and annotations.
• Provides a more comprehensive set of utilities and tools for working with JSON data.
• Offers better performance and scalability compared to JSON-java.

Cons of Jackson

• Has a steeper learning curve due to its more complex API and feature set.
• May be overkill for simple JSON parsing tasks, where JSON-java could be a more lightweight option.
• Requires additional dependencies, which can increase the overall project size.

Code Comparison

JSON-java:

JSONObject obj = new JSONObject();
obj.put("name", "John Doe");
obj.put("age", 30);

Jackson:

ObjectMapper mapper = new ObjectMapper();
Map<String, Object> data = new HashMap<>();
data.put("name", "John Doe");
data.put("age", 30);
String json = mapper.writeValueAsString(data);

Pros of Alibaba/fastjson

• Performance: Fastjson is known for its exceptional performance, often outperforming other JSON parsing libraries in terms of speed and efficiency.
• Comprehensive Feature Set: Fastjson provides a wide range of features, including support for custom serializers/deserializers, annotations, and advanced data binding capabilities.
• Active Development: The Fastjson project is actively maintained and regularly updated, ensuring compatibility with the latest JSON standards and addressing any issues or vulnerabilities.

Cons of Alibaba/fastjson

• Security Concerns: Fastjson has faced some security vulnerabilities in the past, which have raised concerns about its overall security posture.
• Licensing: Fastjson is licensed under the Apache License 2.0, which may not be compatible with all project requirements or preferences.
• Ecosystem Integration: Compared to JSON-java, Fastjson may have a smaller ecosystem of integrations and third-party libraries, which could limit its adoption in certain environments.

Code Comparison

JSON-java:

JSONObject obj = new JSONObject();
obj.put("name", "John Doe");
obj.put("age", 30);
obj.put("email", "john.doe@example.com");
System.out.println(obj.toString());

Fastjson:

JSONObject obj = new JSONObject();
obj.put("name", "John Doe");
obj.put("age", 30);
obj.put("email", "john.doe@example.com");
System.out.println(JSON.toJSONString(obj));

The code snippets demonstrate the basic usage of both JSON-java and Fastjson for creating a JSON object, adding key-value pairs, and serializing the object to a JSON string. The main difference is in the serialization method, where Fastjson uses the JSON.toJSONString() function, while JSON-java uses the toString() method.

Pros of json-iterator/java

• Faster performance compared to stleary/JSON-java, with claims of up to 2x faster parsing and serialization.
• Supports a wider range of data types, including BigDecimal, BigInteger, and AtomicInteger.
• Provides a more flexible and customizable API, allowing for easier integration with different use cases.

Cons of json-iterator/java

• Smaller community and fewer contributors compared to the well-established stleary/JSON-java project.
• May have a steeper learning curve due to its more complex and feature-rich API.
• Potential compatibility issues with existing code that relies on the stleary/JSON-java library.

Code Comparison

stleary/JSON-java:

JSONObject obj = new JSONObject();
obj.put("name", "John");
obj.put("age", 30);
obj.put("city", "New York");
System.out.println(obj.toString());

json-iterator/java:

JsonObject obj = JsonObject.builder()
    .add("name", "John")
    .add("age", 30)
    .add("city", "New York")
    .build();
System.out.println(obj.toString());

Pros of Moshi

• Annotation-based configuration: Moshi provides a more flexible and extensible approach to JSON serialization and deserialization, allowing developers to customize the process using annotations.
• Kotlin support: Moshi has first-class support for Kotlin, making it a great choice for Kotlin-based projects.
• Adapter-based architecture: Moshi's adapter-based architecture allows for easy integration with other libraries and custom data types.

Cons of Moshi

• Larger dependency footprint: Moshi has a larger dependency footprint compared to JSON-java, which may be a concern for projects with strict size requirements.
• Steeper learning curve: Moshi's more advanced features and annotation-based configuration may have a steeper learning curve for developers who are new to the library.

Code Comparison

JSON-java:

JSONObject obj = new JSONObject();
obj.put("name", "John Doe");
obj.put("age", 30);
obj.put("email", "john.doe@example.com");
System.out.println(obj.toString());

Moshi:

val moshi = Moshi.Builder().build()
val jsonAdapter = moshi.adapter(Person::class.java)

val person = Person("John Doe", 30, "john.doe@example.com")
val json = jsonAdapter.toJson(person)
println(json)