Spring Boot Developer Solutions
Solutions for Spring context failures, port conflicts, DataSource configuration, and REST annotations.
Spring Boot Error Fixes (4)
Spring Boot Port 8080 Already in Use
Fix WebServerException: Port 8080 was already in use by killing the conflicting process or assigning a custom port.
Spring Boot Ambiguous Handler Methods
Resolve IllegalStateException: Ambiguous mapping caused by duplicate @GetMapping or @PostMapping path signatures.
Spring Boot Failed to Configure DataSource
Fix 'Failed to configure a DataSource: url attribute is not specified and no embedded datasource could be configured'.
Spring Boot Bean Creation Exception
Troubleshoot BeanCreationException: Error creating bean with name and UnsatisfiedDependencyException in Spring context.
Spring Boot Programming Tutorials (5)
Spring Boot REST API Tutorial
Build a production-grade, secure REST API with Spring Boot 3, Java 21, and Spring Data JPA from scratch.
Spring Boot JWT Authentication
Implement stateless JSON Web Token (JWT) authentication, refresh tokens, and Spring Security 6 authorization.
Spring Boot with PostgreSQL Database
Connect Spring Boot to PostgreSQL using HikariCP connection pooling, Docker, and Liquibase migrations.
Spring Boot with MongoDB
Build reactive and document-based microservices using Spring Data MongoDB and MongoRepository.
Spring Boot Unit Testing with JUnit 5 & Mockito
Write clean, robust unit and integration tests for Spring Boot controllers and services using Mockito and MockMvc.