add metric filter

spring-security-rest-full/src/main/java/org/baeldung/web/controller/RootController.java

@@ -5,17 +5,23 @@ import java.net.URI;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
+import org.baeldung.web.metric.MetricService;
 import org.baeldung.web.util.LinkUtil;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.http.HttpStatus;
 import org.springframework.stereotype.Controller;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.ResponseBody;
 import org.springframework.web.bind.annotation.ResponseStatus;
 import org.springframework.web.util.UriTemplate;
 
 @Controller
 public class RootController {
 
+    @Autowired
+    private MetricService metricService;
+
     public RootController() {
         super();
     }
@@ -34,4 +40,9 @@ public class RootController {
         response.addHeader("Link", linkToFoo);
     }
 
+    @RequestMapping(value = "/metric", method = RequestMethod.GET)
+    @ResponseBody
+    public String getMetric() {
+        return metricService.getFullMetric();
+    }
 }

spring-security-rest-full/src/main/java/org/baeldung/web/metric/MetricFilter.java

@@ -0,0 +1,36 @@
+package org.baeldung.web.metric;
+
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+public class MetricFilter implements Filter {
+
+    private MetricService metricService;
+
+    @Override
+    public void init(final FilterConfig config) throws ServletException {
+        metricService = new MetricService();
+    }
+
+    @Override
+    public void doFilter(final ServletRequest request, final ServletResponse response, final FilterChain chain) throws java.io.IOException, ServletException {
+        final HttpServletRequest httpRequest = ((HttpServletRequest) request);
+        final String req = httpRequest.getMethod() + " " + httpRequest.getRequestURI();
+
+        chain.doFilter(request, response);
+
+        final int status = ((HttpServletResponse) response).getStatus();
+        metricService.increaseCount(req, status);
+    }
+
+    @Override
+    public void destroy() {
+
+    }
+}

spring-security-rest-full/src/main/java/org/baeldung/web/metric/MetricService.java

@@ -0,0 +1,35 @@
+package org.baeldung.web.metric;
+
+import java.util.HashMap;
+
+import org.springframework.stereotype.Service;
+
+@Service
+public class MetricService {
+
+    private static HashMap<String, HashMap<Integer, Integer>> metricMap = new HashMap<String, HashMap<Integer, Integer>>();
+
+    public MetricService() {
+        super();
+    }
+
+    public void increaseCount(final String request, final int status) {
+        HashMap<Integer, Integer> statusMap = metricMap.get(request);
+        if (statusMap == null) {
+            statusMap = new HashMap<Integer, Integer>();
+        }
+
+        Integer count = statusMap.get(status);
+        if (count == null) {
+            count = 1;
+        } else {
+            count++;
+        }
+        statusMap.put(status, count);
+        metricMap.put(request, statusMap);
+    }
+
+    public String getFullMetric() {
+        return metricMap.entrySet().toString();
+    }
+}

spring-security-rest-full/src/main/webapp/WEB-INF/web.xml

@@ -51,6 +51,17 @@
         <filter-name>springSecurityFilterChain</filter-name>
         <url-pattern>/*</url-pattern>
     </filter-mapping>
+    
+    <!-- Metric filter -->
+    <filter>
+	    <filter-name>metricFilter</filter-name>
+	    <filter-class>org.baeldung.web.metric.MetricFilter</filter-class>
+    </filter>
+
+	<filter-mapping>
+		<filter-name>metricFilter</filter-name>
+		<url-pattern>/*</url-pattern>
+	</filter-mapping>
 
     <welcome-file-list>
         <welcome-file>index.html</welcome-file>