Pros of Spring Boot

• Mature ecosystem with extensive documentation and community support
• Wide range of integrations and starter dependencies
• Excellent tooling support, including Spring Tool Suite and IDE plugins

Cons of Spring Boot

• Larger memory footprint and slower startup times
• More complex configuration for advanced use cases
• Steeper learning curve for beginners due to its extensive feature set

Code Comparison

Spring Boot:

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

Quarkus:

@QuarkusMain
public class Application {
    public static void main(String... args) {
        Quarkus.run(args);
    }
}

Both frameworks aim to simplify Java application development, but they differ in their approach. Spring Boot focuses on providing a comprehensive ecosystem with a wide range of features, while Quarkus emphasizes fast startup times and low memory usage, making it particularly suitable for cloud-native and serverless applications.

Spring Boot's maturity and extensive ecosystem make it a popular choice for enterprise applications, while Quarkus's performance optimizations and native compilation support make it attractive for microservices and containerized deployments.

Pros of Micronaut

• Faster startup time and lower memory footprint
• Built-in support for serverless and cloud-native applications
• Extensive support for reactive programming

Cons of Micronaut

• Smaller ecosystem and community compared to Quarkus
• Less extensive documentation and learning resources
• Fewer integrations with enterprise Java technologies

Code Comparison

Micronaut:

@Controller("/hello")
public class HelloController {
    @Get("/{name}")
    public String hello(String name) {
        return "Hello, " + name + "!";
    }
}

Quarkus:

@Path("/hello")
public class HelloResource {
    @GET
    @Path("/{name}")
    @Produces(MediaType.TEXT_PLAIN)
    public String hello(@PathParam String name) {
        return "Hello, " + name + "!";
    }
}

Both frameworks offer similar syntax for creating RESTful endpoints, but Micronaut uses Spring-like annotations while Quarkus follows JAX-RS standards. Micronaut's approach is more concise, while Quarkus aligns more closely with traditional Java EE practices.

Pros of Vert.x

• Lightweight and flexible, allowing for more granular control over application architecture
• Supports multiple programming languages, not limited to Java
• Mature project with a long history and established ecosystem

Cons of Vert.x

• Steeper learning curve, especially for developers new to reactive programming
• Less opinionated, requiring more manual configuration and setup
• Lacks some of the out-of-the-box features and integrations provided by Quarkus

Code Comparison

Vert.x:

Vertx vertx = Vertx.vertx();
vertx.createHttpServer().requestHandler(req -> {
  req.response().putHeader("content-type", "text/plain").end("Hello from Vert.x!");
}).listen(8080);

Quarkus:

@Path("/hello")
public class GreetingResource {
    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String hello() {
        return "Hello from Quarkus!";
    }
}

Vert.x offers a more low-level approach, giving developers direct control over server creation and request handling. Quarkus, on the other hand, provides a higher-level abstraction with JAX-RS annotations, simplifying the process of creating RESTful endpoints.

Pros of Helidon

• Lightweight and modular design, allowing for faster startup times and lower memory footprint
• Strong support for reactive programming models, particularly with Helidon Nima
• Seamless integration with Oracle Cloud Infrastructure (OCI) services

Cons of Helidon

• Smaller community and ecosystem compared to Quarkus
• Less extensive documentation and fewer examples available
• Limited native image support compared to Quarkus' GraalVM integration

Code Comparison

Helidon (Reactive WebServer):

Routing.builder()
    .get("/greet", (req, res) -> res.send("Hello, World!"))
    .build();
WebServer.create(routing).start();

Quarkus (RESTEasy):

@Path("/greet")
public class GreetingResource {
    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String hello() {
        return "Hello, World!";
    }
}

Both frameworks offer concise ways to create web endpoints, but Helidon's approach is more focused on reactive programming, while Quarkus leverages JAX-RS annotations for a more traditional Java EE style.

Pros of Graal

• More versatile, supporting multiple languages beyond Java
• Advanced JIT compilation and optimization techniques
• Broader ecosystem with GraalVM Enterprise for enhanced performance

Cons of Graal

• Steeper learning curve and more complex configuration
• Longer build times for native images
• Less focus on microservices and cloud-native development

Code Comparison

Quarkus (simplified REST endpoint):

@Path("/hello")
public class GreetingResource {
    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String hello() {
        return "Hello from Quarkus";
    }
}

Graal (using Micronaut framework for comparison):

@Controller("/hello")
public class GreetingController {
    @Get(produces = MediaType.TEXT_PLAIN)
    public String hello() {
        return "Hello from GraalVM";
    }
}

Both examples showcase similar simplicity in creating REST endpoints, but Quarkus is more focused on microservices and cloud-native applications, while Graal provides a more general-purpose runtime environment.

Pros of JDK

• Comprehensive Java runtime and development kit
• Widely adopted and supported across various platforms
• Extensive documentation and community resources

Cons of JDK

• Larger footprint and slower startup times
• Not optimized for cloud-native or microservices architectures
• Requires more configuration for modern application development

Code Comparison

JDK (Hello World example):

public class HelloWorld {
    public static void main(String[] args) {
        System.out.println("Hello, World!");
    }
}

Quarkus (RESTful endpoint example):

@Path("/hello")
public class GreetingResource {
    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String hello() {
        return "Hello from RESTEasy Reactive";
    }
}

The JDK example shows a basic Java application, while the Quarkus example demonstrates a RESTful endpoint with minimal code. Quarkus leverages modern Java features and frameworks to simplify development and improve performance in cloud-native environments.