chore(sticker-award): Setup checkstyle linting

Author: scottgerring

sticker-award/README.md

@@ -60,3 +60,69 @@ The API returns standard HTTP status codes and follows the RFC 7807 Problem Deta
 Full API documentation is available in OpenAPI format:
 - Synchronous API: [api.yaml](./docs/api.yaml)
 - Asynchronous API: [async_api.json](./docs/async_api.json)
+
+## Building and Running
+
+### Prerequisites
+- Java 21+
+- Maven 3.8+
+
+### Development
+
+Run in development mode:
+```bash
+./mvnw compile quarkus:dev
+```
+
+### Testing
+
+Run tests:
+```bash
+./mvnw test
+```
+
+Run integration tests:
+```bash
+./mvnw verify
+```
+
+## Code Quality
+
+### Checkstyle
+
+This project uses Checkstyle to enforce coding standards based on the Google Java Style Guide.
+
+**Run Checkstyle validation:**
+```bash
+# Check code style (runs automatically during build)
+./mvnw validate
+
+# Run only Checkstyle check
+./mvnw checkstyle:check
+
+# Generate Checkstyle report (creates HTML report at target/reports/checkstyle.html)
+./mvnw checkstyle:checkstyle
+```
+
+### Spotless (Code Formatting)
+
+This project uses Spotless with Google Java Format to automatically fix code style issues. 
+
+**Format your code:**
+```bash
+# Check if code formatting is correct
+./mvnw spotless:check
+
+# Automatically fix code formatting issues
+./mvnw spotless:apply
+
+# Format and then validate with Checkstyle
+./mvnw spotless:apply validate
+```
+
+**Checkstyle Configuration:**
+- Configuration file: `checkstyle.xml`
+- Suppressions file: `checkstyle-suppressions.xml`
+- Based on Google Java Style Guide (modified for 4-space indentation)
+- Enforces 4-space indentation, 100-character line limit
+- Checks import ordering, Javadoc completeness, and naming conventions

sticker-award/checkstyle-suppressions.xml

@@ -0,0 +1,42 @@
+<?xml version="1.0"?>
+
+<!DOCTYPE suppressions PUBLIC
+        "-//Checkstyle//DTD SuppressionFilter Configuration 1.2//EN"
+        "https://checkstyle.org/dtds/suppressions_1_2.dtd">
+
+<!--
+    Checkstyle suppressions file for Sticker Award application.
+    
+    This file allows you to suppress specific Checkstyle violations for certain files or patterns.
+    Use this sparingly and only when necessary.
+    
+    Examples:
+    - Generated code that you don't control
+    - Third-party code
+    - Specific patterns that are acceptable in your codebase
+-->
+
+<suppressions>
+    <!-- Suppress all checks for generated files -->
+    <suppress files=".*[\\/]generated[\\/].*\.java" checks=".*"/>
+    
+    <!-- Suppress line length checks for test files with long URLs or test data -->
+    <suppress files=".*Test\.java" checks="LineLength" lines="1-999999"/>
+    
+    <!-- Allow missing Javadoc for test methods -->
+    <suppress files=".*Test\.java" checks="MissingJavadocMethod"/>
+    <suppress files=".*Test\.java" checks="JavadocMethod"/>
+    
+    <!-- Allow missing Javadoc for test classes -->
+    <suppress files=".*Test\.java" checks="MissingJavadocType"/>
+    
+    <!-- Suppress abbreviation checks for common patterns like DTO, API, etc. -->
+    <suppress files=".*DTO\.java" checks="AbbreviationAsWordInName"/>
+    <suppress files=".*API\.java" checks="AbbreviationAsWordInName"/>
+    
+    <!-- Allow longer lines in configuration classes -->
+    <suppress files=".*Config\.java" checks="LineLength"/>
+    
+    <!-- Suppress checks for application main classes -->
+    <suppress files=".*Application\.java" checks="HideUtilityClassConstructor"/>
+</suppressions>