Project structure walkthrough in Spring Boot - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the purpose of the 'src/main/resources' folder in a Spring Boot project?

In a typical Spring Boot project, what kind of files do you place inside the 'src/main/resources' folder?

A Java source code files that contain the main application logic.

B Test source code files for unit and integration tests.

C Configuration files, static assets, and templates used by the application.

D Compiled class files generated after building the project.

💡 Hint

Think about where you keep files like application.properties or HTML templates.

The 'src/main/resources' folder holds non-code files like configuration, static files, and templates that the application uses at runtime.

❓ component_behavior

intermediate

What happens if you place a Java class outside 'src/main/java' in a Spring Boot project?

Consider a Java class placed in 'src/test/java' instead of 'src/main/java'. What is the effect on the Spring Boot application?

A The class will only be compiled and used during testing, not in the main application runtime.

B The class will be included in the main application build and run normally.

C The class will cause a build failure due to incorrect folder placement.

D The class will be ignored completely and not compiled or used anywhere.

💡 Hint

Think about the difference between main and test source folders.

Classes in 'src/test/java' are compiled and used only for testing, not included in the main application runtime.

📝 Syntax

advanced

Which folder should you place your Spring Boot controller classes in for proper component scanning?

Given a Spring Boot project with base package 'com.example.app', where should controller classes be placed to be detected automatically?

A com.example.app.services inside 'src/main/resources'

B com.example.controllers outside the base package

C com.example.app.controllers inside 'src/test/java'

D com.example.app.controllers inside 'src/main/java'

💡 Hint

Controllers must be inside the base package or its subpackages.

Spring Boot scans the base package and its subpackages for components like controllers. Placing them inside 'com.example.app.controllers' ensures detection.

🔧 Debug

advanced

Why does Spring Boot fail to find your application.properties file?

You placed your application.properties file in 'src/main/java' instead of 'src/main/resources'. What will happen when you run the app?

A The application will crash with a FileNotFoundException.

B Spring Boot will fail to load the properties file because it only looks in 'src/main/resources'.

C The application.properties file will be ignored but no error will occur.

D Spring Boot will load the properties file without any issues.

💡 Hint

Where does Spring Boot expect configuration files to be?

Spring Boot loads configuration files from the classpath, which includes 'src/main/resources' but not 'src/main/java'. Placing the file in the wrong folder means it won't be found.

❓ lifecycle

expert

What is the role of the 'META-INF' folder inside 'src/main/resources' in a Spring Boot project?

You find a 'META-INF' folder inside 'src/main/resources'. What is its typical purpose in a Spring Boot application?

A It holds metadata files like 'MANIFEST.MF' that describe the packaged jar.

B It stores static web assets like CSS and JavaScript files.

C It contains compiled Java bytecode for the application.

D It contains test reports generated after running tests.

💡 Hint

Think about what metadata about the jar or application might be stored.

The 'META-INF' folder contains metadata files such as 'MANIFEST.MF' that describe the jar file and its contents, important for packaging and deployment.