fix: Linting errors

.github/workflows/main.yml

@@ -1,3 +1,4 @@
+---
 name: CI
 
 on:
@@ -8,7 +9,6 @@ on:
     branches:
       - main
 
-
 concurrency:
   group: ${{ github.ref }}-${{ github.workflow }}
   cancel-in-progress: true
@@ -18,17 +18,17 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - name: Checkout sources
-      uses: actions/checkout@v4
+      - name: Checkout sources
+        uses: actions/checkout@v4
 
-    - name: Setup Java
-      uses: actions/setup-java@v4
-      with:
-        distribution: 'temurin'
-        java-version: 21
+      - name: Setup Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: 21
 
-    - name: Build with Gradle
-      run: ./gradlew build
+      - name: Build with Gradle
+        run: ./gradlew build
 
-    - name: Build Docker image
-      run: docker build --build-arg JAR_FILE=build/libs/\*.jar -t springio/gs-spring-boot-docker .
+      - name: Build Docker image
+        run: docker build --build-arg JAR_FILE=build/libs/*.jar -t springio/gs-spring-boot-docker .

.github/workflows/pull-request.yml

@@ -1,3 +1,4 @@
+---
 name: CI
 
 on:
@@ -8,7 +9,6 @@ on:
     branches:
       - main
 
-
 concurrency:
   group: ${{ github.ref }}-${{ github.workflow }}
   cancel-in-progress: true
@@ -18,17 +18,17 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - name: Checkout sources
-      uses: actions/checkout@v4
+      - name: Checkout sources
+        uses: actions/checkout@v4
 
-    - name: Setup Java
-      uses: actions/setup-java@v4
-      with:
-        distribution: 'temurin'
-        java-version: 21
+      - name: Setup Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'temurin'
+          java-version: 21
 
-    - name: Build with Gradle
-      run: ./gradlew build
+      - name: Build with Gradle
+        run: ./gradlew build
 
-    - name: Build Docker image
-      run: docker build --build-arg JAR_FILE=build/libs/\*.jar -t springio/gs-spring-boot-docker .
+      - name: Build Docker image
+        run: docker build --build-arg JAR_FILE=build/libs/*.jar -t springio/gs-spring-boot-docker .

Dockerfile

@@ -1,4 +1,6 @@
 FROM openjdk:21
-ARG JAR_FILE=build/libs/*.jar
-COPY ${JAR_FILE} app.jar
+RUN addgroup -S spring && adduser -S spring -G spring
+WORKDIR /work/src
+COPY build/libs/*.jar app.jar
+USER spring:spring
 ENTRYPOINT ["java","-jar","/app.jar"]

src/main/java/tw/commonground/backend/BackendApplication.java

@@ -8,14 +8,23 @@
 @SpringBootApplication
 @RestController
 public class BackendApplication {
-
+  /**
+   * Handles requests to the root URL ("/") and returns a greeting message.
+   *
+   * @return A string greeting message.
+   */
   @RequestMapping("/")
   public String home() {
     return "Hello Docker World";
   }
 
-  public static void main(String[] args) {
+  /**
+   * The entry point of the application.
+   *
+   * @param args command-line arguments (if any)
+   */
+  public static void main(final String[] args) {
     SpringApplication.run(BackendApplication.class, args);
   }
 
-}
+}

src/main/java/tw/commonground/backend/package-info.java

@@ -0,0 +1,4 @@
+/**
+ * This package contains classes and interfaces for the backend application of Common Ground.
+ */
+package tw.commonground.backend;