Tpx Assignment - Url Shortener

README.md

@@ -42,3 +42,26 @@ It should:
   - How to build and run locally.
   - Example usage (frontend and API).
   - Any notes or assumptions.
+
+## How to run the application
+
+Prerequisites:
+
+- Docker (with Docker Compose)
+- JDK 21 (required for local backend build/test outside Docker)
+
+- From the repo root, run: docker compose up --build -d
+- Open frontend at http://localhost
+- Backend API is at http://localhost:8585
+- Redis is at localhost:6379 (primarily internal, but exposed)
+
+- Network: defined in docker-compose.yml
+- Volume: defined in docker-compose.yml
+- Port mappings:
+  defined per service in docker-compose.yml
+
+## Notes / Assumptions
+
+- In `backend/src/main/resources/application-docker.yml`, Redis host is set to `host.docker.internal` as a default.
+- In `docker-compose.yml`, backend sets `SPRING_DATA_REDIS_HOST=redis` (and port `6379`) via environment variables.
+- This is intentional and works in Docker Compose because Spring Boot resolves environment variables with higher precedence than values in `application-docker.yml`.

backend/.gitignore

@@ -0,0 +1,39 @@
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+.kotlin
+
+### IntelliJ IDEA ###
+.idea/modules.xml
+.idea/jarRepositories.xml
+.idea/compiler.xml
+.idea/libraries/
+*.iws
+*.iml
+*.ipr
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store

backend/Dockerfile

@@ -0,0 +1,25 @@
+# Stage 1: Build the application
+FROM maven:3.9-eclipse-temurin-21-alpine AS build
+WORKDIR /app
+COPY pom.xml .
+RUN mvn dependency:go-offline -B
+COPY src ./src
+RUN mvn clean package -DskipTests
+
+
+# Stage 2: Create the runtime image using Java 21
+FROM eclipse-temurin:21-jre-alpine
+WORKDIR /app
+RUN addgroup -S spring && adduser -S spring -G spring
+RUN mkdir -p /app/data /app/logs
+COPY --from=build /app/target/*.jar app.jar
+
+VOLUME /tmp
+VOLUME /app/data
+VOLUME /app/logs
+
+EXPOSE 8585
+
+ENTRYPOINT ["java", "-Dspring.profiles.active=docker", "-jar", "app.jar"]
+
+

backend/pom.xml

@@ -0,0 +1,118 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xmlns="http://maven.apache.org/POM/4.0.0"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.tpx.urlshort</groupId>
+    <artifactId>backend</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>21</maven.compiler.source>
+        <maven.compiler.target>21</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <openapi-version>2.6.0</openapi-version>
+        <sqlite-version>3.46.0.0</sqlite-version>
+        <byte-buddy.version>1.15.0</byte-buddy.version>
+    </properties>
+
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>3.3.2</version>
+        <relativePath/>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springdoc</groupId>
+            <artifactId>springdoc-openapi-starter-webmvc-ui</artifactId>
+            <version>${openapi-version}</version> <!-- Use the latest version compatible with your Boot version -->
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-jpa</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-validation</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.xerial</groupId>
+            <artifactId>sqlite-jdbc</artifactId>
+            <version>${sqlite-version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.hibernate.orm</groupId>
+            <artifactId>hibernate-community-dialects</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-redis</artifactId>
+        </dependency>
+
+        <!-- Test -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>repackage</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+
+            <!-- Standard Unit Tests Plugin -->
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <configuration>
+                    <systemPropertyVariables>
+                        <net.bytebuddy.experimental>true</net.bytebuddy.experimental>
+                    </systemPropertyVariables>
+                </configuration>
+            </plugin>
+
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-failsafe-plugin</artifactId>
+                <configuration>
+                    <systemPropertyVariables>
+                        <net.bytebuddy.experimental>true</net.bytebuddy.experimental>
+                    </systemPropertyVariables>
+                </configuration>
+            </plugin>
+
+        </plugins>
+    </build>
+
+
+</project>

backend/src/main/java/com/tpx/urlshort/AppStarter.java

@@ -0,0 +1,26 @@
+package com.tpx.urlshort;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class AppStarter implements CommandLineRunner {
+
+    private static final Logger logger = LoggerFactory.getLogger(AppStarter.class);
+
+    @Value("${spring.application.name:URL Shortener}")
+    private String appName;
+
+    public static void main(String[] args) {
+        SpringApplication.run(AppStarter.class, args);
+    }
+
+    @Override
+    public void run(String... args) throws Exception {
+        logger.info("Application **** {} **** started", appName);
+    }
+}

backend/src/main/java/com/tpx/urlshort/cache/redis/RedisUrlCacheService.java

@@ -0,0 +1,79 @@
+package com.tpx.urlshort.cache.redis;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.dao.DataAccessException;
+import org.springframework.data.redis.RedisConnectionFailureException;
+import org.springframework.data.redis.core.StringRedisTemplate;
+import org.springframework.stereotype.Service;
+
+import java.time.Duration;
+import java.util.Optional;
+
+@Service
+public class RedisUrlCacheService implements UrlCacheService {
+
+  private static final Logger logger = LoggerFactory.getLogger(RedisUrlCacheService.class);
+
+  private final StringRedisTemplate redisTemplate;
+  private final Duration ttl;
+
+  public RedisUrlCacheService(StringRedisTemplate redisTemplate,
+      @Value("${app.cache.ttl-seconds:600}") long ttlSeconds) {
+    this.redisTemplate = redisTemplate;
+    this.ttl = Duration.ofSeconds(ttlSeconds);
+  }
+
+  @Override
+  public Optional<String> get(String alias) {
+    try {
+      validateAlias(alias);
+      String value = redisTemplate.opsForValue().get(buildKey(alias));
+      return Optional.ofNullable(value);
+    } catch (IllegalArgumentException e) {
+      logger.warn("Redis cache get failed for alias '{}': {}", alias, e.getMessage());
+      return Optional.empty();
+    } catch (DataAccessException e) {
+      logger.warn("Redis cache get failed for alias '{}': {}", alias, e.getMessage());
+      return Optional.empty();
+    }
+  }
+
+  @Override
+  public void put(String alias, String actualUrl) {
+    try {
+      validateAlias(alias);
+      if (actualUrl == null || actualUrl.isBlank()) {
+        throw new IllegalArgumentException("Actual URL must not be null or empty");
+      }
+      redisTemplate.opsForValue().set(buildKey(alias), actualUrl, ttl);
+    } catch (IllegalArgumentException e) {
+      logger.warn("Redis cache put failed for alias '{}': {}", alias, e.getMessage());
+    } catch (DataAccessException e) {
+      logger.warn("Redis cache put failed for alias '{}': {}", alias, e.getMessage());
+    }
+  }
+
+  @Override
+  public void evict(String alias) {
+    try {
+      validateAlias(alias);
+      redisTemplate.delete(buildKey(alias));
+    } catch (IllegalArgumentException e) {
+      logger.warn("Redis cache evict failed for alias '{}': {}", alias, e.getMessage());
+    } catch (DataAccessException e) {
+      logger.warn("Redis cache evict failed for alias '{}': {}", alias, e.getMessage());
+    }
+  }
+
+  private String buildKey(String alias) {
+    return "url:" + alias;
+  }
+
+  private void validateAlias(String alias) {
+    if (alias == null || alias.isBlank()) {
+      throw new IllegalArgumentException("Alias must not be null or empty");
+    }
+  }
+}

backend/src/main/java/com/tpx/urlshort/cache/redis/UrlCacheService.java

@@ -0,0 +1,12 @@
+package com.tpx.urlshort.cache.redis;
+
+import java.util.Optional;
+
+public interface UrlCacheService {
+
+  Optional<String> get(String alias);
+
+  void put(String alias, String actualUrl);
+
+  void evict(String alias);
+}

backend/src/main/java/com/tpx/urlshort/config/CorsConfig.java

@@ -0,0 +1,31 @@
+package com.tpx.urlshort.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.config.annotation.CorsRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+@Configuration
+public class CorsConfig {
+
+    private final CorsProperties corsProperties;
+
+    public CorsConfig(CorsProperties corsProperties) {
+        this.corsProperties = corsProperties;
+    }
+
+    @Bean
+    public WebMvcConfigurer corsConfigurer() {
+
+        return new WebMvcConfigurer() {
+            @Override
+            public void addCorsMappings(CorsRegistry registry) {
+                registry.addMapping("/**")
+                        .allowedOrigins(corsProperties.getAllowedOrigins().toArray(new String[0]))
+                        .allowedMethods(corsProperties.getAllowedMethods().toArray(new String[0]))
+                        .allowedHeaders(corsProperties.getAllowedHeaders().toArray(new String[0]))
+                        .allowCredentials(corsProperties.isAllowCredentials());
+            }
+        };
+    }
+}