Adding CheckStyle checks

.github/workflows/build.yml

@@ -26,7 +26,7 @@ jobs:
         run: npm version from-git --no-git-tag-version --prefix docs
 
       - name: Test dRAGon
-        run: gradle npmInstall npmLint test
+        run: gradle criticalLintGradle checkstyleMain npmInstall npmLint test
 
       - name: Build Documentation
         run: npm install --prefix docs && npm run build --prefix docs

backend/build.gradle

@@ -1,9 +1,11 @@
 plugins {
 	id 'java'
+	id 'java-library'
+	id 'checkstyle' 
 	id 'application'
 	id 'org.springframework.boot' version '3.2.5'
 	id 'io.spring.dependency-management' version '1.1.4'
-	id "org.springdoc.openapi-gradle-plugin" version "1.8.0"
+	id 'org.springdoc.openapi-gradle-plugin' version '1.8.0'
 }
 
 group = 'ai'
@@ -54,6 +56,13 @@ openApi {
     }
 }
 
+checkstyle {
+	toolVersion '10.16.0'
+    config = rootProject.resources.text.fromFile('backend/checkstyle.xml')
+    ignoreFailures = false
+    maxWarnings = 0
+}
+
 bootJar {
     manifest {
         attributes(

backend/checkstyle.xml

@@ -0,0 +1,28 @@
+<?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"/>
+  <module name="TreeWalker">
+    <module name="CommentsIndentation"/>
+    <module name="PackageDeclaration"/>
+    <module name="AvoidStarImport"/>
+    <module name="ConstantName"/>
+    <module name="EmptyBlock"/>
+    <module name="Indentation">
+      <property name="basicOffset" value="4"/>
+      <property name="caseIndent" value="4"/>
+      <property name="throwsIndent" value="4"/>
+      <property name="arrayInitIndent" value="4"/>
+      <property name="lineWrappingIndentation" value="4"/>
+    </module>
+  </module>
+  <module name="NewlineAtEndOfFile"/>
+  <module name="LineLength">
+    <property name="max" value="160"/>
+  </module>
+  <module name="FileTabCharacter">
+    <property name="eachLine" value="false"/>
+  </module>
+</module>

backend/src/main/java/ai/dragon/DragonApplication.java

@@ -5,7 +5,7 @@
 
 @SpringBootApplication
 public class DragonApplication {
-	public static void main(String[] args) {
-		SpringApplication.run(DragonApplication.class, args);
-	}
+    public static void main(String[] args) {
+        SpringApplication.run(DragonApplication.class, args);
+    }
 }

backend/src/main/java/ai/dragon/component/DirectoryStructureComponent.java

@@ -71,4 +71,4 @@ private void createDatabaseDirectory() {
             logger.debug("Database directory already exists : " + databaseDirectory);
         }
     }
-}
+}

backend/src/main/java/ai/dragon/entity/ProviderEntity.java

@@ -32,7 +32,9 @@ public class ProviderEntity implements IAbstractEntity {
     @Schema(description = "Type of the Provider")
     private ProviderType type;
 
-    @Schema(description = "Headers to be sent to the Provider (if applicable) in the form of key-value pairs. Could be used for authentication with API keys, tokens, etc.")
+    @Schema(description = """
+            Headers to be sent to the Provider (if applicable) in the form of key-value pairs.
+            Could be used for authentication with API keys, tokens, etc.""")
     private Map<String, String> httpHeaders;
 
     public ProviderEntity() {