chore: Migrate Java version from 8 to 11

CONTRIBUTING.md

@@ -5,6 +5,134 @@
 - Follow README Quickstart.
 - Create branches: `devin/<short-purpose>`.
 
+## IDE Configuration for Java 11
+
+After updating to Java 11, developers need to configure their IDE to use Java 11 for this project.
+
+### Eclipse / Spring Tool Suite (STS)
+
+1. **Install Java 11 JDK**
+   - Download and install Java 11 JDK from
+     [Oracle](https://www.oracle.com/java/technologies/javase/jdk11-archive-downloads.html)
+     or [AdoptOpenJDK](https://adoptopenjdk.net/)
+   - Set JAVA_HOME environment variable to Java 11 installation path
+
+2. **Configure Eclipse JDK**
+   - Navigate to: `Window > Preferences > Java > Installed JREs`
+   - Click `Add...` and select `Standard VM`
+   - Browse to your Java 11 installation directory
+   - Click `Finish` and ensure Java 11 is checked as the default
+
+3. **Configure Project Settings**
+   - Right-click project in Project Explorer > `Properties`
+   - Navigate to `Java Build Path > Libraries`
+   - Remove old JRE System Library
+   - Click `Add Library > JRE System Library > Next`
+   - Select `Workspace default JRE (JavaSE-11)` or `Alternate JRE` and choose Java 11
+   - Click `Finish`
+
+4. **Configure Compiler Settings**
+   - Navigate to `Java Compiler` in project properties
+   - Set `Compiler compliance level` to `11`
+   - Ensure `Use default compliance settings` is checked
+   - Click `Apply and Close`
+
+5. **Enable Lombok**
+   - Download lombok.jar from <https://projectlombok.org/download>
+   - Run: `java -jar lombok.jar`
+   - Select Eclipse installation directory and click `Install/Update`
+   - Restart Eclipse
+
+6. **Refresh and Rebuild**
+   - Run: `mvn clean install` from terminal or Maven view
+   - Project > Clean > Clean all projects
+   - Project > Build Project
+
+### IntelliJ IDEA
+
+1. **Install Java 11 JDK**
+   - Download and install Java 11 JDK
+   - IDEA can auto-download JDKs: `File > Project Structure > SDKs > + > Download JDK`
+
+2. **Configure Project SDK**
+   - Navigate to: `File > Project Structure > Project`
+   - Set `Project SDK` to Java 11
+   - Set `Project language level` to `11 - Local variable syntax for lambda parameters`
+   - Click `Apply`
+
+3. **Configure Module Settings**
+   - In `Project Structure > Modules`
+   - Select your module and go to `Sources` tab
+   - Set `Language level` to `11`
+   - Click `Apply`
+
+4. **Configure Maven**
+   - Navigate to: `File > Settings > Build, Execution, Deployment > Build Tools > Maven > Runner`
+   - Set `JRE` to Java 11
+   - Click `Apply`
+
+5. **Enable Lombok Plugin**
+   - Navigate to: `File > Settings > Plugins`
+   - Search for "Lombok" and install the official plugin
+   - Restart IDEA
+   - Enable annotation processing: `Settings > Build, Execution, Deployment > Compiler > Annotation Processors`
+   - Check `Enable annotation processing`
+
+6. **Reimport Maven Project**
+   - Right-click on `pom.xml` > `Maven > Reload Project`
+   - Or use Maven tool window: `Reload All Maven Projects` button
+
+### Visual Studio Code
+
+1. **Install Java 11 JDK**
+   - Download and install Java 11 JDK
+   - Set JAVA_HOME environment variable
+
+2. **Install Extensions**
+   - Install "Extension Pack for Java" (includes Language Support, Debugger, Maven, etc.)
+   - Install "Lombok Annotations Support for VS Code"
+
+3. **Configure Java Home**
+   - Open Settings (Ctrl+,) or `File > Preferences > Settings`
+   - Search for "java.configuration.runtimes"
+   - Edit in settings.json:
+
+     ```json
+     "java.configuration.runtimes": [
+       {
+         "name": "JavaSE-11",
+         "path": "/path/to/java-11-jdk",
+         "default": true
+       }
+     ]
+     ```
+
+4. **Configure Maven**
+   - Ensure Maven is installed (or use wrapper: `./mvnw`)
+   - VS Code will automatically detect Maven projects
+
+5. **Reload Project**
+   - Command Palette (Ctrl+Shift+P): `Java: Clean Java Language Server Workspace`
+   - Restart VS Code
+   - Run: `mvn clean install` in terminal
+
+### Verification
+
+After configuring your IDE, verify the setup:
+
+```bash
+# Compile project
+mvn clean compile
+
+# Run tests
+mvn test
+
+# Run application
+mvn spring-boot:run
+```
+
+Access the application at: <http://localhost:8989/bank-api/swagger-ui.html>
+
 ## Coding Standards
 
 - Format + lint before pushing.

README.md

@@ -38,7 +38,7 @@ https://projectlombok.org/setup/eclipse
 
 ### Prerequisites
 
-* Java 8
+* Java 11
 * Spring Tool Suite 4 or similar IDE
 * [Maven](https://maven.apache.org/) - Dependency Management
 

README_NEW.md

@@ -37,7 +37,7 @@ for testing, and students studying enterprise Java application architecture.
 
 ### Prerequisites
 
-- Java 8 or higher
+- Java 11 or higher
 - Maven 3.6+ (or use included Maven wrapper)
 - Any modern IDE (Spring Tool Suite, IntelliJ IDEA, Eclipse)
 

pom.xml

@@ -15,7 +15,7 @@
 	<description>Bank App Spring Boot Project</description>
 
 	<properties>
-		<java.version>1.8</java.version>
+		<java.version>11</java.version>
 	</properties>
 
 	<dependencies>