feat: add web traffic logger

src/main/java/com/onixbyte/deltaforceguide/config/AppConfig.java

@@ -1,10 +1,26 @@
 package com.onixbyte.deltaforceguide.config;
 
+import com.onixbyte.deltaforceguide.interceptor.TrafficInterceptor;
 import com.onixbyte.deltaforceguide.properties.AppProperties;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 
 @Configuration
 @EnableConfigurationProperties(AppProperties.class)
-public class AppConfig {
+public class AppConfig implements WebMvcConfigurer {
+
+    private final TrafficInterceptor trafficInterceptor;
+
+    @Autowired
+    public AppConfig(TrafficInterceptor trafficInterceptor) {
+        this.trafficInterceptor = trafficInterceptor;
+    }
+
+    @Override
+    public void addInterceptors(InterceptorRegistry registry) {
+        registry.addInterceptor(trafficInterceptor);
+    }
 }

src/main/java/com/onixbyte/deltaforceguide/interceptor/TrafficInterceptor.java

@@ -0,0 +1,46 @@
+package com.onixbyte.deltaforceguide.interceptor;
+
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import org.jspecify.annotations.NonNull;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+import org.springframework.web.servlet.HandlerInterceptor;
+
+@Component
+public class TrafficInterceptor implements HandlerInterceptor {
+
+    private static final Logger log = LoggerFactory.getLogger(TrafficInterceptor.class);
+
+    @Override
+    public boolean preHandle(
+            @NonNull HttpServletRequest request,
+            @NonNull HttpServletResponse response,
+            @NonNull Object handler
+    ) {
+        var ip = resolveClientIp(request);
+        var method = request.getMethod();
+        var uri = request.getRequestURI();
+        var query = request.getQueryString();
+        var contentType = request.getContentType();
+        var contentLength = request.getContentLength();
+        var userAgent = request.getHeader("User-Agent");
+
+        log.info("Request method={}, uri={}, query={}, ip={}, content-type={}, content-length={}, user-agent={}",
+                method, uri, query, ip, contentType, contentLength, userAgent);
+        return true;
+    }
+
+    private String resolveClientIp(HttpServletRequest request) {
+        var xForwardedFor = request.getHeader("X-Forwarded-For");
+        if (xForwardedFor != null && !xForwardedFor.isBlank()) {
+            return xForwardedFor.split(",")[0].trim();
+        }
+        var xRealIp = request.getHeader("X-Real-IP");
+        if (xRealIp != null && !xRealIp.isBlank()) {
+            return xRealIp.trim();
+        }
+        return request.getRemoteAddr();
+    }
+}