Add Checkstyle for code style enforcement

.github/workflows/gradle.yml

@@ -1,6 +1,6 @@
 name: Java CI with Gradle
 
-on: [push, pull_request]
+on: [ push, pull_request ]
 
 permissions:
   contents: read
@@ -10,40 +10,40 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - name: Checkout repository
-      uses: actions/checkout@v4
-
-    - name: Set up JDK 21
-      uses: actions/setup-java@v4
-      with:
-        java-version: '21'
-        distribution: 'temurin'
-        cache: gradle
-
-    - name: Grant execute permission for gradlew
-      run: chmod +x gradlew
-
-    - name: Build with Gradle
-      run: ./gradlew build -x test
-
-    - name: Run tests
-      run: ./gradlew test
-
-    - name: Publish Test Results
-      uses: actions/upload-artifact@v4
-      if: always()
-      with:
-        name: test-results
-        path: |
-          build/reports/tests/test/
-          build/test-results/test/
-
-    - name: Update status check
-      if: success()
-      run: echo "Tests passed" > status.txt || echo "Tests failed" > status.txt
-
-    - name: Upload status check
-      uses: actions/upload-artifact@v4
-      with:
-        name: status-check
-        path: status.txt
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up JDK 21
+        uses: actions/setup-java@v4
+        with:
+          java-version: '21'
+          distribution: 'temurin'
+          cache: gradle
+
+      - name: Grant execute permission for gradlew
+        run: chmod +x gradlew
+
+      - name: Run Checkstyle
+        run: ./gradlew checkstyleMain checkstyleTest
+
+      - name: Build with Gradle
+        run: ./gradlew build -x test
+
+      - name: Run tests
+        run: ./gradlew test
+
+      - name: Publish Test Results
+        uses: actions/upload-artifact@v4
+        if: always()
+        with:
+          name: test-results
+          path: |
+            build/reports/tests/test/
+            build/test-results/test/
+
+      - name: Publish Checkstyle Results
+        uses: actions/upload-artifact@v4
+        if: always()
+        with:
+          name: checkstyle-results
+          path: build/reports/checkstyle/

build.gradle

@@ -4,6 +4,20 @@ plugins {
     id 'org.springframework.boot' version '3.3.4'
     id 'io.spring.dependency-management' version '1.1.6'
     id 'org.flywaydb.flyway' version "10.18.0"
+    id 'checkstyle'
+}
+
+checkstyle {
+    toolVersion = "10.8.0"
+    configFile = file("config/checkstyle/checkstyle.xml")
+    maxWarnings = 0
+}
+
+tasks.withType(Checkstyle).configureEach {
+    reports {
+        xml.required = false
+        html.required = true
+    }
 }
 
 group = 'com.activecourses'

config/checkstyle/checkstyle.xml

@@ -0,0 +1,61 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+        "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+        "https://checkstyle.org/dtds/configuration_1_3.dtd">
+
+<module name="Checker">
+    <property name="charset" value="UTF-8"/>
+    <property name="severity" value="warning"/>
+    <property name="fileExtensions" value="java, properties, xml"/>
+
+    <!-- Checks for whitespace -->
+    <module name="FileTabCharacter">
+        <property name="eachLine" value="true"/>
+    </module>
+
+    <module name="LineLength">
+        <property name="max" value="120"/>
+        <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
+    </module>
+
+    <module name="TreeWalker">
+        <!-- Checks for Indentation -->
+        <module name="Indentation">
+            <property name="basicOffset" value="4"/>
+            <property name="braceAdjustment" value="0"/>
+            <property name="caseIndent" value="4"/>
+            <property name="throwsIndent" value="4"/>
+            <property name="lineWrappingIndentation" value="8"/>
+            <property name="arrayInitIndent" value="4"/>
+        </module>
+
+        <!-- Checks for whitespace -->
+        <module name="EmptyForIteratorPad"/>
+        <module name="GenericWhitespace"/>
+        <module name="MethodParamPad"/>
+        <module name="NoWhitespaceAfter"/>
+        <module name="NoWhitespaceBefore"/>
+        <module name="OperatorWrap"/>
+        <module name="ParenPad"/>
+        <module name="TypecastParenPad"/>
+        <module name="WhitespaceAfter"/>
+        <module name="WhitespaceAround"/>
+
+        <!-- Modifier Checks -->
+        <module name="ModifierOrder"/>
+
+        <!-- Checks for blocks -->
+        <module name="EmptyBlock"/>
+        <module name="LeftCurly"/>
+        <module name="NeedBraces"/>
+        <module name="RightCurly"/>
+
+        <!-- Checks for common coding problems -->
+        <module name="EmptyStatement"/>
+        <module name="MultipleVariableDeclarations"/>
+
+        <!-- Miscellaneous other checks -->
+        <module name="ArrayTypeStyle"/>
+        <module name="UpperEll"/>
+    </module>
+</module>

src/main/java/com/activecourses/upwork/UpworkApplication.java

@@ -6,11 +6,8 @@
 
 @SpringBootApplication
 @EnableJpaAuditing
-
 public class UpworkApplication {
-
-	public static void main(String[] args) {
-		SpringApplication.run(UpworkApplication.class, args);
-	}
-
+    public static void main(String[] args) {
+        SpringApplication.run(UpworkApplication.class, args);
+    }
 }

src/main/java/com/activecourses/upwork/config/security/jwt/AuthEntryPointJwt.java

@@ -24,7 +24,9 @@ public class AuthEntryPointJwt implements AuthenticationEntryPoint {
     private static final Logger logger = LoggerFactory.getLogger(AuthEntryPointJwt.class);
 
     @Override
-    public void commence(HttpServletRequest request, HttpServletResponse response, AuthenticationException authException)
+    public void commence(HttpServletRequest request,
+                         HttpServletResponse response,
+                         AuthenticationException authException)
             throws IOException, ServletException {
         logger.error("Unauthorized error: {}", authException.getMessage());
 

src/main/java/com/activecourses/upwork/config/security/jwt/AuthTokenFilter.java

@@ -28,7 +28,11 @@ public class AuthTokenFilter extends OncePerRequestFilter {
     private static final Logger logger = LoggerFactory.getLogger(AuthTokenFilter.class);
 
     @Override
-    protected void doFilterInternal(@NonNull HttpServletRequest request, @NonNull HttpServletResponse response, @NonNull FilterChain filterChain) throws ServletException, IOException {
+    protected void doFilterInternal(@NonNull HttpServletRequest request,
+                                    @NonNull HttpServletResponse response,
+                                    @NonNull FilterChain filterChain)
+            throws ServletException, IOException {
+
         try {
             String jwt = jwtService.getJwtFromCookies(request);
             if (jwt != null && jwtService.validateJwtToken(jwt)) {

src/main/java/com/activecourses/upwork/config/security/jwt/JwtService.java

@@ -70,7 +70,11 @@ public ResponseCookie getCleanJwtCookie() {
     }
 
     public ResponseCookie getCleanJwtRefreshCookie() {
-        return ResponseCookie.from(jwtRefreshCookie, "").path("/api/auth/refresh-token").maxAge(0).httpOnly(true).build();
+        return ResponseCookie.from(jwtRefreshCookie, "")
+                .path("/api/auth/refresh-token")
+                .maxAge(0)
+                .httpOnly(true)
+                .build();
     }
 
     public String generateAccessToken(UserDetails userDetails) {

src/main/java/com/activecourses/upwork/controller/role/RoleController.java

@@ -96,7 +96,10 @@ public ResponseEntity<ResponseDto> assignRolesToUser(@PathVariable int id, @Requ
                 : buildResponseEntity(HttpStatus.NOT_FOUND, false, null, "User not found.");
     }
 
-    private ResponseEntity<ResponseDto> buildResponseEntity(HttpStatus status, boolean success, Object data, Object error) {
+    private ResponseEntity<ResponseDto> buildResponseEntity(HttpStatus status,
+                                                            boolean success,
+                                                            Object data,
+                                                            Object error) {
         return ResponseEntity
                 .status(status)
                 .body(ResponseDto

src/main/java/com/activecourses/upwork/controller/user/UserController.java

@@ -30,10 +30,18 @@ public class UserController {
     @Operation(summary = "Get all users",
             description = "Retrieve a paginated list of all users. Only accessible by users with the ROLE_ADMIN role.",
             parameters = {
-                    @Parameter(name = "pageNo", in = ParameterIn.QUERY, description = "Page number", schema = @Schema(type = "integer", defaultValue = "0")),
-                    @Parameter(name = "pageSize", in = ParameterIn.QUERY, description = "Page size", schema = @Schema(type = "integer", defaultValue = "10")),
-                    @Parameter(name = "sortBy", in = ParameterIn.QUERY, description = "Sort by", schema = @Schema(type = "string", defaultValue = "id")),
-                    @Parameter(name = "sortDir", in = ParameterIn.QUERY, description = "Sort direction", schema = @Schema(type = "string", defaultValue = "asc"))
+                    @Parameter(name = "pageNo", in = ParameterIn.QUERY,
+                            description = "Page number",
+                            schema = @Schema(type = "integer", defaultValue = "0")),
+                    @Parameter(name = "pageSize", in = ParameterIn.QUERY,
+                            description = "Page size",
+                            schema = @Schema(type = "integer", defaultValue = "10")),
+                    @Parameter(name = "sortBy", in = ParameterIn.QUERY,
+                            description = "Sort by",
+                            schema = @Schema(type = "string", defaultValue = "id")),
+                    @Parameter(name = "sortDir", in = ParameterIn.QUERY,
+                            description = "Sort direction",
+                            schema = @Schema(type = "string", defaultValue = "asc"))
             }
     )
     @PreAuthorize("hasRole('ROLE_ADMIN')")

src/main/java/com/activecourses/upwork/dto/authentication/login/LoginRequestDto.java

@@ -20,8 +20,12 @@ public class LoginRequestDto {
     @Size(min = 6, message = "Password must be at least 6 characters long")
     private String password;
 
-    public LoginRequestDto(@Email(message = "Email is not valid") @NotEmpty(message = "Email is required") @NotNull(message = "Email is required") String email,
-                           @NotEmpty(message = "Password is required") @NotNull(message = "Password is required") @Size(min = 6, message = "Password must be at least 6 characters long") String password) {
+    public LoginRequestDto(@Email(message = "Email is not valid")
+                           @NotEmpty(message = "Email is required")
+                           @NotNull(message = "Email is required") String email,
+                           @NotEmpty(message = "Password is required")
+                           @NotNull(message = "Password is required")
+                           @Size(min = 6, message = "Password must be at least 6 characters long") String password) {
         this.email = email;
         this.password = password;
     }

src/main/java/com/activecourses/upwork/model/RefreshToken.java

@@ -32,10 +32,10 @@ public class RefreshToken {
 
     @Override
     public String toString() {
-        return "RefreshToken{" +
-               "id=" + id +
-               ", token='" + token + '\'' +
-               ", expiryDate=" + expiryDate +
-               '}';
+        return "RefreshToken{"
+               + "id=" + id
+               + ", token='" + token + '\''
+               + ", expiryDate=" + expiryDate
+               + '}';
     }
 }

src/main/java/com/activecourses/upwork/model/User.java

@@ -66,7 +66,7 @@ public class User implements UserDetails, Principal {
 
     @OneToOne(mappedBy = "user", cascade = CascadeType.ALL, optional = true)
     private RefreshToken refreshToken;
-    @OneToOne(mappedBy = "user",cascade = CascadeType.ALL)
+    @OneToOne(mappedBy = "user", cascade = CascadeType.ALL)
     private UserProfile userProfile;
     @ManyToMany(fetch = FetchType.EAGER)
     @JoinTable(

src/main/java/com/activecourses/upwork/service/RefreshTokenService.java

@@ -35,7 +35,9 @@ public class RefreshTokenService {
     private final UserRepository userRepository;
     private final JwtService jwtService;
 
-    public RefreshTokenService(RefreshTokenRepository refreshTokenRepository, UserRepository userRepository, JwtService jwtService) {
+    public RefreshTokenService(RefreshTokenRepository refreshTokenRepository,
+                               UserRepository userRepository,
+                               JwtService jwtService) {
         this.refreshTokenRepository = refreshTokenRepository;
         this.userRepository = userRepository;
         this.jwtService = jwtService;
@@ -119,7 +121,9 @@ public RefreshToken createRefreshToken(int userId) {
     public void verifyExpiration(RefreshToken token) {
         if (token.getExpiryDate().compareTo(Instant.now()) < 0) {
             refreshTokenRepository.delete(token);
-            throw new TokenRefreshException(token.getToken(), "Refresh token was expired. Please sign in again to obtain a new refresh token.");
+            throw new TokenRefreshException(token.getToken(),
+                    "Refresh token was expired. "
+                    + "Please sign in again to obtain a new refresh token.");
         }
 
     }

src/main/java/com/activecourses/upwork/service/authentication/AuthServiceImpl.java

@@ -92,19 +92,24 @@ public ResponseDto login(LoginRequestDto loginRequestDto) {
         }
 
         Authentication authentication = authenticationManager
-                .authenticate(new UsernamePasswordAuthenticationToken(loginRequestDto.getEmail(), loginRequestDto.getPassword()));
+                .authenticate(new UsernamePasswordAuthenticationToken(
+                        loginRequestDto.getEmail(),
+                        loginRequestDto.getPassword()
+                ));
 
         SecurityContextHolder.getContext().setAuthentication(authentication);
 
-        UserDetails userDetails = customUserDetailsService.loadUserByUsername(loginRequestDto.getEmail());
+        UserDetails userDetails = customUserDetailsService
+                .loadUserByUsername(loginRequestDto.getEmail());
 
         ResponseCookie jwtCookie = jwtService.generateJwtCookie(userDetails);
 
         int userId = ((User) userDetails).getId();
 
         RefreshToken refreshToken = refreshTokenService.createRefreshToken(userId);
 
-        ResponseCookie refreshJwtCookie = jwtService.generateRefreshJwtCookie(refreshToken.getToken());
+        ResponseCookie refreshJwtCookie = jwtService
+                .generateRefreshJwtCookie(refreshToken.getToken());
 
         return ResponseDto
                 .builder()
@@ -117,7 +122,8 @@ public ResponseDto login(LoginRequestDto loginRequestDto) {
     @Override
     public ResponseEntity<ResponseDto> logout() {
         logger.info("User logout attempt");
-        Object principal = SecurityContextHolder.getContext().getAuthentication().getPrincipal();
+        Object principal = SecurityContextHolder.getContext()
+                .getAuthentication().getPrincipal();
         if (!principal.toString().equals("anonymousUser")) {
             int userId = ((User) principal).getId();
             refreshTokenService.deleteByUserId(userId);
@@ -166,7 +172,8 @@ public User findByEmail(String email) {
     @Override
     public void sendVerificationEmail(User user) {
         logger.info("Sending verification email to: {}", user.getEmail());
-        String verificationLink = "http://localhost:8080/api/users/verify?token=" + user.getVerificationToken();
+        String verificationLink = "http://localhost:8080/api/users/verify?token="
+                                  + user.getVerificationToken();
 
         SimpleMailMessage message = new SimpleMailMessage();
         message.setTo(user.getEmail());
@@ -196,7 +203,10 @@ public boolean reactivateUser(int userId) {
     }
 
     static User unwrapUser(Optional<User> entity) {
-        if (entity.isPresent()) return entity.get();
-        else throw new UnsupportedOperationException("Unimplemented method 'unwrapUser'");
+        if (entity.isPresent()) {
+            return entity.get();
+        } else {
+            throw new UnsupportedOperationException("Unimplemented method 'unwrapUser'");
+        }
     }
 }