Spring Boot Custom 404 Response - Spring-boot Typing CST Test
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Spring Boot Custom 404 Response — Spring-boot Code
Custom error handling for 404 requests.
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.servlet.NoHandlerFoundException;
@SpringBootApplication
public class ErrorApplication {
public static void main(String[] args) {
SpringApplication.run(ErrorApplication.class, args);
}
}
@RestController
@ControllerAdvice
class ErrorController {
@ExceptionHandler(NoHandlerFoundException.class)
@ResponseStatus(HttpStatus.NOT_FOUND)
public String handle404() {
return "Custom 404 Not Found";
}
}Spring-boot Language Guide
Spring Boot is a Java-based framework that simplifies building production-ready Spring applications. It provides convention-over-configuration, embedded servers, and production-grade features for microservices and web applications.
Primary Use Cases
- ▸RESTful API development
- ▸Microservices architecture
- ▸Enterprise backend systems
- ▸Web applications with Spring MVC
- ▸Integration with databases and messaging systems
Notable Features
- ▸Embedded web servers for standalone deployment
- ▸Auto-configuration to reduce boilerplate
- ▸Production-ready metrics, health checks, and logging
- ▸Spring ecosystem integration (Security, Data, Batch)
- ▸Opinionated defaults with override options
Origin & Creator
Spring Boot was created by Pivotal Software (now part of VMware) in 2014 to simplify Spring framework development and deployment.
Industrial Note
Spring Boot is preferred in enterprise, cloud-native, and microservices applications where scalability, maintainability, and rapid development are critical.
Quick Explain
- ▸Spring Boot allows developers to create stand-alone, production-ready Spring applications quickly.
- ▸It provides embedded servers like Tomcat, Jetty, or Undertow, removing deployment complexity.
- ▸Supports auto-configuration to reduce boilerplate code.
- ▸Integrates seamlessly with Spring ecosystem: Spring Data, Spring Security, Spring MVC, etc.
- ▸Widely used for microservices, REST APIs, and enterprise-grade backend systems.
Core Features
- ▸Dependency injection and inversion-of-control via Spring Core
- ▸Auto-configuration based on classpath and beans
- ▸Embedded server (Tomcat, Jetty, Undertow)
- ▸Spring MVC for web and REST endpoints
- ▸Spring Data integration for ORM and database access
Learning Path
- ▸Learn Java basics
- ▸Understand Spring Core and dependency injection
- ▸Learn Spring Boot auto-configuration
- ▸Build REST APIs with Spring MVC
- ▸Deploy Spring Boot applications
Practical Examples
- ▸REST API for e-commerce
- ▸User authentication and authorization service
- ▸Microservices backend with Eureka and Ribbon
- ▸Data processing service with Spring Batch
- ▸Monitoring and logging service with Actuator
Comparisons
- ▸Spring Boot vs Spring MVC: Boot adds auto-configuration and embedded server
- ▸Spring Boot vs Flask: Java enterprise ecosystem vs Python lightweight
- ▸Spring Boot vs FastAPI: Spring Boot is Java, FastAPI is Python with async support
- ▸Spring Boot vs Express.js: Full-featured vs minimal Node.js framework
- ▸Spring Boot vs Micronaut: Boot is mature, Micronaut optimized for startup and memory
Strengths
- ▸Rapid development with minimal configuration
- ▸Extensive ecosystem and community support
- ▸Enterprise-grade, scalable architecture
- ▸Embedded server simplifies deployment
- ▸Rich production features (metrics, monitoring, health checks)
Limitations
- ▸Heavier than micro-frameworks for very small apps
- ▸Startup time longer than lightweight frameworks
- ▸Learning curve for Spring ecosystem concepts
- ▸Overhead if many auto-configurations are unused
- ▸Can feel complex for simple projects
When NOT to Use
- ▸Very small scripts or microservices requiring minimal footprint
- ▸Projects needing very fast startup with low memory
- ▸Teams unfamiliar with Java/Spring ecosystem
- ▸Applications not requiring enterprise features
- ▸Prototypes needing rapid experimentation with lightweight tools
Cheat Sheet
- ▸@SpringBootApplication -> main class annotation
- ▸SpringApplication.run(App.class, args) -> start app
- ▸@RestController -> define REST endpoints
- ▸@Service -> business logic layer
- ▸@Repository -> data access layer
FAQ
- ▸Is Spring Boot free?
- ▸Yes - open-source under Apache 2.0 license.
- ▸Can Spring Boot create standalone apps?
- ▸Yes - with embedded Tomcat/Jetty/Undertow.
- ▸Is Spring Boot suitable for production?
- ▸Yes - widely used in enterprise-grade applications.
- ▸Does Spring Boot include ORM?
- ▸It integrates with Spring Data and JPA for ORM.
- ▸How does Spring Boot compare to Flask?
- ▸Spring Boot is Java/enterprise-focused; Flask is Python/lightweight.
30-Day Skill Plan
- ▸Week 1: Java fundamentals
- ▸Week 2: Spring Core and Boot basics
- ▸Week 3: REST APIs and database integration
- ▸Week 4: Security and microservices
- ▸Week 5: Deployment and monitoring
Final Summary
- ▸Spring Boot simplifies building production-ready Spring applications.
- ▸Supports embedded servers and auto-configuration.
- ▸Integrates with the Spring ecosystem for enterprise features.
- ▸Ideal for microservices, REST APIs, and scalable backends.
- ▸Widely adopted in enterprise and cloud-native applications.
Project Structure
- ▸src/main/java/ - main application code
- ▸src/main/resources/ - configuration files, static assets, templates
- ▸controllers/ - REST controllers
- ▸services/ - business logic classes
- ▸repositories/ - database access interfaces
Monetization
- ▸Backend for SaaS platforms
- ▸Enterprise application development
- ▸API-as-a-service offerings
- ▸E-commerce backend systems
- ▸Cloud-native microservices
Productivity Tips
- ▸Use Spring Boot starters to simplify dependencies
- ▸Leverage auto-configuration to reduce boilerplate
- ▸Use embedded servers for quick testing
- ▸Automate tests and deployments
- ▸Monitor metrics and logs proactively
Basic Concepts
- ▸Spring Boot application instance - entry point class
- ▸Controllers - define REST endpoints
- ▸Services - business logic layer
- ▸Repositories - data access layer with Spring Data
- ▸Beans - managed objects via dependency injection