How to solve java.lang.NoClassDefFoundError: org/springframework/beans/factory/SmartInitializingSingleton in Spring Boot [Solved]

Problem:
I was trying to run a HelloWorld program using Spring Boot when I got this error:

Exception in thread "main" java.lang.IllegalStateException: Could not evaluate condition on org.springframework.boot.autoconfigure.PropertyPlaceholderAutoConfiguration#propertySourcesPlaceholderConfigurer due to internal class not found. This can happen if you are @ComponentScanning a springframework package (e.g. if you put a @ComponentScan in the default package by mistake)
at org.springframework.boot.autoconfigure.condition.SpringBootCondition.matches(SpringBootCondition.java:52)
at org.springframework.context.annotation.ConditionEvaluator.shouldSkip(ConditionEvaluator.java:92)
at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForBeanMethod(ConfigurationClassBeanDefinitionReader.java:174)
at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForConfigurationClass(ConfigurationClassBeanDefinitionReader.java:136)

Top 10 Projects You can Build to Learn Spring Boot in 2025

Hello guys, I have always said that there is no better way to learn anything then actually doing it and its 100% true for Spring Boot, one of the popular Framework for Java application Development. In my 20 years of experience, I have found that the best way to learn Java and Spring Boot is building projects. When you build project, common task surface them like creating a List or sorting a List and then you research and learn. Those learning stuck and make you better developer. Building project also have many advantage like it allows you to use a lot of technologies like Git, IntelliJIDEA, Hibernate, APIs etc together to build something which you can showcase to your potential employer. 

Difference between @GetMapping @PostMapping @PutMapping @DeleteMapping @PatchMapping

In the world of web development, the Spring Framework is widely known for its versatility and ease of use. It provides several annotations that simplify the process of handling HTTP requests and mapping them to specific methods in Spring controllers. Among these annotations, @GetMapping, @PostMapping, @PutMapping, @DeleteMapping, and @PatchMapping are some of the most commonly used ones. In this article, we will explore each of these annotations in detail, highlighting their purposes, differences, and providing examples to better understand their usage.