[JAVA-9604] Refactor and code clean-up for Metrics article

spring-boot-modules/spring-boot-actuator/README.md

@@ -12,3 +12,4 @@ The "REST With Spring" Classes: http://bit.ly/restwithspring
 - [Health Indicators in Spring Boot](https://www.baeldung.com/spring-boot-health-indicators)
 - [How to Enable All Endpoints in Spring Boot Actuator](https://www.baeldung.com/spring-boot-actuator-enable-endpoints)
 - [Spring Boot Startup Actuator Endpoint](https://www.baeldung.com/spring-boot-actuator-startup)
+- [Metrics for your Spring REST API](https://www.baeldung.com/spring-rest-api-metrics)

spring-boot-modules/spring-boot-actuator/pom.xml

@@ -23,6 +23,10 @@
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-web</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.apache.tomcat.embed</groupId>
+            <artifactId>tomcat-embed-jasper</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-data-jpa</artifactId>
@@ -35,6 +39,16 @@
             <groupId>com.h2database</groupId>
             <artifactId>h2</artifactId>
         </dependency>
+        <dependency>
+            <groupId>javax.servlet</groupId>
+            <artifactId>javax.servlet-api</artifactId>
+            <scope>provided</scope>
+        </dependency>
+        <dependency>
+            <groupId>javax.servlet</groupId>
+            <artifactId>jstl</artifactId>
+            <scope>runtime</scope>
+        </dependency>
         <dependency>
             <groupId>org.springframework.boot</groupId>
             <artifactId>spring-boot-starter-test</artifactId>
@@ -51,6 +65,10 @@
             <artifactId>spring-security-test</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.awaitility</groupId>
+            <artifactId>awaitility</artifactId>
+        </dependency>
     </dependencies>
 
     <build>

spring-boot-modules/spring-boot-actuator/src/main/java/com/baeldung/metrics/MetricsApplication.java

@@ -0,0 +1,42 @@
+package com.baeldung.metrics;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.actuate.autoconfigure.security.servlet.ManagementWebSecurityAutoConfiguration;
+import org.springframework.boot.actuate.autoconfigure.security.servlet.SecurityRequestMatchersManagementContextConfiguration;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.data.jpa.JpaRepositoriesAutoConfiguration;
+import org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration;
+import org.springframework.boot.autoconfigure.security.servlet.SecurityFilterAutoConfiguration;
+import org.springframework.boot.autoconfigure.security.servlet.UserDetailsServiceAutoConfiguration;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.scheduling.annotation.EnableScheduling;
+import org.springframework.web.context.request.RequestContextListener;
+
+import javax.servlet.ServletContext;
+
+@EnableScheduling
+@ComponentScan("com.baeldung.metrics")
+@SpringBootApplication
+public class MetricsApplication extends SpringBootServletInitializer {
+
+    @Override
+    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
+        return application.sources(MetricsApplication.class);
+    }
+
+    @Override
+    public void onStartup(ServletContext sc) {
+        // Manages the lifecycle of the root application context
+        sc.addListener(new RequestContextListener());
+    }
+
+    public static void main(final String[] args) {
+        // only load properties for this application
+        System.setProperty("spring.config.location", "classpath:application-metrics.properties");
+        SpringApplication.run(MetricsApplication.class, args);
+    }
+
+}

spring-boot-modules/spring-boot-actuator/src/main/java/com/baeldung/metrics/WebConfig.java

@@ -1,4 +1,4 @@
-package com.baeldung.spring;
+package com.baeldung.metrics;
 
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ComponentScan;
@@ -10,14 +10,10 @@ import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
 import org.springframework.web.servlet.view.InternalResourceViewResolver;
 
 @Configuration
-@ComponentScan("com.baeldung.web")
+@ComponentScan("com.baeldung.metrics")
 @EnableWebMvc
 public class WebConfig implements WebMvcConfigurer {
 
-    public WebConfig() {
-        super();
-    }
-
     @Bean
     public ViewResolver viewResolver() {
         final InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
@@ -26,11 +22,10 @@ public class WebConfig implements WebMvcConfigurer {
         return viewResolver;
     }
 
-    // API
     @Override
     public void addViewControllers(final ViewControllerRegistry registry) {
-        registry.addViewController("/graph.html");
+        registry.addViewController("/metrics/graph.html");
-        registry.addViewController("/homepage.html");
+        registry.addViewController("/metrics/homepage.html");
     }
 
 }

spring-boot-modules/spring-boot-actuator/src/main/java/com/baeldung/metrics/controller/MetricsController.java

@@ -0,0 +1,41 @@
+package com.baeldung.metrics.controller;
+
+import com.baeldung.metrics.service.InMemoryMetricService;
+import com.baeldung.metrics.service.MetricService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.ResponseBody;
+
+import java.util.Map;
+
+@Controller
+@RequestMapping(value = "/metrics")
+@ResponseBody
+public class MetricsController {
+
+    @Autowired
+    private InMemoryMetricService metricService;
+
+    // change the qualifier to use the in-memory implementation
+    @Autowired
+    @Qualifier("customActuatorMetricService")
+    private MetricService graphMetricService;
+
+    @GetMapping(value = "/metric")
+    public Map<String, Map<Integer, Integer>> getMetric() {
+        return metricService.getFullMetric();
+    }
+
+    @GetMapping(value = "/status-metric")
+    public Map<Integer, Integer> getStatusMetric() {
+        return metricService.getStatusMetric();
+    }
+
+    @GetMapping(value = "/metric-graph-data")
+    public Object[][] getMetricData() {
+        return graphMetricService.getGraphData();
+    }
+}

spring-boot-modules/spring-boot-actuator/src/main/java/com/baeldung/metrics/filter/MetricFilter.java

@@ -1,4 +1,11 @@
-package com.baeldung.web.metric;
+package com.baeldung.metrics.filter;
+
+import com.baeldung.metrics.service.CustomActuatorMetricService;
+import com.baeldung.metrics.service.InMemoryMetricService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+import org.springframework.web.context.WebApplicationContext;
+import org.springframework.web.context.support.WebApplicationContextUtils;
 
 import javax.servlet.Filter;
 import javax.servlet.FilterChain;
@@ -9,24 +16,23 @@ import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.stereotype.Component;
-import org.springframework.web.context.support.WebApplicationContextUtils;
-
 @Component
 public class MetricFilter implements Filter {
 
     @Autowired
-    private IMetricService metricService;
+    private InMemoryMetricService metricService;
 
     @Autowired
-    private ICustomActuatorMetricService actMetricService;
+    private CustomActuatorMetricService actMetricService;
 
     @Override
-    public void init(final FilterConfig config) throws ServletException {
+    public void init(final FilterConfig config) {
         if (metricService == null || actMetricService == null) {
-            metricService = (IMetricService) WebApplicationContextUtils.getRequiredWebApplicationContext(config.getServletContext()).getBean("metricService");
+            WebApplicationContext appContext = WebApplicationContextUtils
-            actMetricService = WebApplicationContextUtils.getRequiredWebApplicationContext(config.getServletContext()).getBean(CustomActuatorMetricService.class);
+              .getRequiredWebApplicationContext(config.getServletContext());
+
+            metricService = appContext.getBean(InMemoryMetricService.class);
+            actMetricService = appContext.getBean(CustomActuatorMetricService.class);
         }
     }
 
@@ -42,8 +48,4 @@ public class MetricFilter implements Filter {
         actMetricService.increaseCount(status);
     }
 
-    @Override
-    public void destroy() {
-
-    }
 }

spring-boot-modules/spring-boot-actuator/src/main/java/com/baeldung/metrics/service/ActuatorMetricService.java

@@ -1,32 +1,31 @@
-package com.baeldung.web.metric;
+package com.baeldung.metrics.service;
+
+import io.micrometer.core.instrument.Counter;
+import io.micrometer.core.instrument.Meter;
+import io.micrometer.core.instrument.MeterRegistry;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Service;
 
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
 
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.scheduling.annotation.Scheduled;
-import org.springframework.stereotype.Service;
-
-import io.micrometer.core.instrument.Counter;
-import io.micrometer.core.instrument.Meter;
-import io.micrometer.core.instrument.MeterRegistry;
-
 @Service
-public class ActuatorMetricService implements IActuatorMetricService {
+public class ActuatorMetricService implements MetricService {
+
+    private static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd HH:mm");
 
     @Autowired
     private MeterRegistry publicMetrics;
 
-    private final List<ArrayList<Integer>> statusMetricsByMinute;
+    private final List<List<Integer>> statusMetricsByMinute;
     private final List<String> statusList;
-    private static final SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm");
 
     public ActuatorMetricService() {
-        super();
+        statusMetricsByMinute = new ArrayList<>();
-        statusMetricsByMinute = new ArrayList<ArrayList<Integer>>();
+        statusList = new ArrayList<>();
-        statusList = new ArrayList<String>();
     }
 
     @Override
@@ -36,19 +35,19 @@ public class ActuatorMetricService implements IActuatorMetricService {
         final int rowCount = statusMetricsByMinute.size() + 1;
         final Object[][] result = new Object[rowCount][colCount];
         result[0][0] = "Time";
-        int j = 1;
 
+        int j = 1;
         for (final String status : statusList) {
             result[0][j] = status;
             j++;
         }
 
         for (int i = 1; i < rowCount; i++) {
-            result[i][0] = dateFormat.format(new Date(current.getTime() - (60000 * (rowCount - i))));
+            result[i][0] = DATE_FORMAT.format(new Date(current.getTime() - (60000L * (rowCount - i))));
         }
 
         List<Integer> minuteOfStatuses;
-        List<Integer> last = new ArrayList<Integer>();
+        List<Integer> last = new ArrayList<>();
 
         for (int i = 1; i < rowCount; i++) {
             minuteOfStatuses = statusMetricsByMinute.get(i - 1);
@@ -64,11 +63,9 @@ public class ActuatorMetricService implements IActuatorMetricService {
         return result;
     }
 
-    // Non - API
+    @Scheduled(fixedDelayString = "${fixedDelay.in.milliseconds:60000}")
-
-    @Scheduled(fixedDelay = 60000)
     private void exportMetrics() {
-        final ArrayList<Integer> lastMinuteStatuses = initializeStatuses(statusList.size());
+        final List<Integer> lastMinuteStatuses = initializeStatuses(statusList.size());
 
         for (final Meter counterMetric : publicMetrics.getMeters()) {
             updateMetrics(counterMetric, lastMinuteStatuses);
@@ -77,34 +74,32 @@ public class ActuatorMetricService implements IActuatorMetricService {
         statusMetricsByMinute.add(lastMinuteStatuses);
     }
 
-    private ArrayList<Integer> initializeStatuses(final int size) {
+    private List<Integer> initializeStatuses(int size) {
-        final ArrayList<Integer> counterList = new ArrayList<Integer>();
+        List<Integer> counterList = new ArrayList<>();
         for (int i = 0; i < size; i++) {
             counterList.add(0);
         }
         return counterList;
     }
 
-    private void updateMetrics(final Meter counterMetric, final ArrayList<Integer> statusCount) {
+    private void updateMetrics(Meter counterMetric, List<Integer> statusCount) {
-        String status = "";
-        int index = -1;
-        int oldCount = 0;
 
-        if (counterMetric.getId().getName().contains("counter.status.")) {
+        String metricName = counterMetric.getId().getName();
-            status = counterMetric.getId().getName().substring(15, 18); // example 404, 200
+
+        if (metricName.contains("counter.status.")) {
+            // example 404, 200
+            String status = metricName.substring(15, 18);
             appendStatusIfNotExist(status, statusCount);
-            index = statusList.indexOf(status);
+            int index = statusList.indexOf(status);
-            oldCount = statusCount.get(index) == null ? 0 : statusCount.get(index);
+            int oldCount = statusCount.get(index) == null ? 0 : statusCount.get(index);
             statusCount.set(index, (int)((Counter) counterMetric).count() + oldCount);
         }
     }
 
-    private void appendStatusIfNotExist(final String status, final ArrayList<Integer> statusCount) {
+    private void appendStatusIfNotExist(String status, List<Integer> statusCount) {
         if (!statusList.contains(status)) {
             statusList.add(status);
             statusCount.add(0);
         }
     }
-
-    //
 }

spring-boot-modules/spring-boot-actuator/src/main/java/com/baeldung/metrics/service/CustomActuatorMetricService.java

@@ -1,40 +1,36 @@
-package com.baeldung.web.metric;
+package com.baeldung.metrics.service;
+
+import io.micrometer.core.instrument.Counter;
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.search.Search;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.stereotype.Service;
 
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
 
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.scheduling.annotation.Scheduled;
-import org.springframework.stereotype.Service;
-
-import io.micrometer.core.instrument.Counter;
-import io.micrometer.core.instrument.MeterRegistry;
-import io.micrometer.core.instrument.search.Search;
-
 @Service
-public class CustomActuatorMetricService implements ICustomActuatorMetricService {
+public class CustomActuatorMetricService implements MetricService {
+
+    private static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd HH:mm");
 
     @Autowired
     private MeterRegistry registry;
 
-    private final List<ArrayList<Integer>> statusMetricsByMinute;
+    private final List<List<Integer>> statusMetricsByMinute;
     private final List<String> statusList;
-    private static final SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm");
 
     public CustomActuatorMetricService() {
-        super();
+        statusMetricsByMinute = new ArrayList<>();
-        statusMetricsByMinute = new ArrayList<ArrayList<Integer>>();
+        statusList = new ArrayList<>();
-        statusList = new ArrayList<String>();
     }
 
-    // API
+    public void increaseCount(int status) {
-
-    @Override
-    public void increaseCount(final int status) {
         String counterName = "counter.status." + status;
-        registry.counter(counterName).increment(1);
+        registry.counter(counterName).increment();
         if (!statusList.contains(counterName)) {
             statusList.add(counterName);
         }
@@ -55,7 +51,7 @@ public class CustomActuatorMetricService implements ICustomActuatorMetricService
         }
 
         for (int i = 1; i < rowCount; i++) {
-            result[i][0] = dateFormat.format(new Date(current.getTime() - (60000 * (rowCount - i))));
+            result[i][0] = DATE_FORMAT.format(new Date(current.getTime() - (60000L * (rowCount - i))));
         }
 
         List<Integer> minuteOfStatuses;
@@ -72,19 +68,17 @@ public class CustomActuatorMetricService implements ICustomActuatorMetricService
         return result;
     }
 
-    // Non - API
+    @Scheduled(fixedDelayString = "${fixedDelay.in.milliseconds:60000}")
-
-    @Scheduled(fixedDelay = 60000)
     private void exportMetrics() {
-        final ArrayList<Integer> statusCount = new ArrayList<Integer>();
+        List<Integer> statusCount = new ArrayList<>();
         for (final String status : statusList) {
             Search search = registry.find(status);
-            if (search != null) {
             Counter counter = search.counter();
-                statusCount.add(counter != null ? ((int) counter.count()) : 0);
+            if (counter == null) {
-                registry.remove(counter);
-            } else {
                 statusCount.add(0);
+            } else {
+                statusCount.add((int) counter.count());
+                registry.remove(counter);
             }
         }
         statusMetricsByMinute.add(statusCount);

spring-boot-modules/spring-boot-actuator/src/main/java/com/baeldung/metrics/service/InMemoryMetricService.java

@@ -0,0 +1,112 @@
+package com.baeldung.metrics.service;
+
+import org.springframework.stereotype.Service;
+
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+@Service
+public class InMemoryMetricService implements MetricService {
+
+    private static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd HH:mm");
+
+    private final Map<String, Map<Integer, Integer>> metricMap;
+    private final Map<Integer, Integer> statusMetric;
+    private final Map<String, Map<Integer, Integer>> timeMap;
+
+    public InMemoryMetricService() {
+        metricMap = new ConcurrentHashMap<>();
+        statusMetric = new ConcurrentHashMap<>();
+        timeMap = new ConcurrentHashMap<>();
+    }
+
+    public void increaseCount(String request, int status) {
+        increaseMainMetric(request, status);
+        increaseStatusMetric(status);
+        updateTimeMap(status);
+    }
+
+    public Map<String, Map<Integer, Integer>> getFullMetric() {
+        return metricMap;
+    }
+
+    public Map<Integer, Integer> getStatusMetric() {
+        return statusMetric;
+    }
+
+    public Object[][] getGraphData() {
+        final int colCount = statusMetric.keySet().size() + 1;
+        final Set<Integer> allStatus = statusMetric.keySet();
+        final int rowCount = timeMap.keySet().size() + 1;
+
+        final Object[][] result = new Object[rowCount][colCount];
+        result[0][0] = "Time";
+
+        int j = 1;
+        for (final int status : allStatus) {
+            result[0][j] = status;
+            j++;
+        }
+        int i = 1;
+        Map<Integer, Integer> tempMap;
+        for (final Entry<String, Map<Integer, Integer>> entry : timeMap.entrySet()) {
+            result[i][0] = entry.getKey();
+            tempMap = entry.getValue();
+            for (j = 1; j < colCount; j++) {
+                result[i][j] = tempMap.get((Integer) result[0][j]);
+                if (result[i][j] == null) {
+                    result[i][j] = 0;
+                }
+            }
+            i++;
+        }
+
+        for (int k = 1; k < result[0].length; k++) {
+            result[0][k] = result[0][k].toString();
+        }
+
+        return result;
+    }
+
+    private void increaseMainMetric(String request, int status) {
+        Map<Integer, Integer> statusMap = metricMap.get(request);
+        if (statusMap == null) {
+            statusMap = new ConcurrentHashMap<>();
+        }
+
+        Integer count = statusMap.get(status);
+        if (count == null) {
+            count = 1;
+        } else {
+            count++;
+        }
+        statusMap.put(status, count);
+        metricMap.put(request, statusMap);
+    }
+
+    private void increaseStatusMetric(int status) {
+        statusMetric.merge(status, 1, Integer::sum);
+    }
+
+    private void updateTimeMap(int status) {
+        final String time = DATE_FORMAT.format(new Date());
+        Map<Integer, Integer> statusMap = timeMap.get(time);
+        if (statusMap == null) {
+            statusMap = new ConcurrentHashMap<>();
+        }
+
+        Integer count = statusMap.get(status);
+        if (count == null) {
+            count = 1;
+        } else {
+            count++;
+        }
+        statusMap.put(status, count);
+        timeMap.put(time, statusMap);
+    }
+
+}

spring-boot-modules/spring-boot-actuator/src/main/java/com/baeldung/metrics/service/MetricService.java

@@ -0,0 +1,7 @@
+package com.baeldung.metrics.service;
+
+public interface MetricService {
+
+    Object[][] getGraphData();
+
+}

spring-boot-modules/spring-boot-actuator/src/main/resources/application-metrics.properties

@@ -0,0 +1,9 @@
+management.endpoints.web.exposure.include=info,health,metrics
+
+# JPA and Security is not required for Metrics application
+spring.autoconfigure.exclude= org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration, \
+  org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration, \
+  org.springframework.boot.autoconfigure.jdbc.DataSourceTransactionManagerAutoConfiguration, \
+  org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration, \
+  org.springframework.boot.actuate.autoconfigure.security.servlet.ManagementWebSecurityAutoConfiguration, \
+  org.springframework.boot.autoconfigure.security.servlet.SecurityFilterAutoConfiguration

spring-boot-modules/spring-boot-actuator/src/main/webapp/WEB-INF/view/metrics/graph.jsp

@@ -11,7 +11,7 @@
 	});
 
 	function drawChart() {
-		$.get("<c:url value="/metric-graph-data"/>",
+		$.get("<c:url value="/metrics/metric-graph-data"/>",
 				function(mydata) {
 
 					var data = google.visualization.arrayToDataTable(mydata);

spring-boot-modules/spring-boot-actuator/src/main/webapp/WEB-INF/web.xml

@@ -16,7 +16,7 @@
     </context-param>
     <context-param>
         <param-name>contextConfigLocation</param-name>
-        <param-value>com.baeldung.spring</param-value>
+        <param-value>com.baeldung.metrics</param-value>
     </context-param>
 
     <listener>
@@ -37,7 +37,7 @@
     <!-- Metric filter -->
     <filter>
         <filter-name>metricFilter</filter-name>
-        <filter-class>com.baeldung.web.metric.MetricFilter</filter-class>
+        <filter-class>com.baeldung.metrics.filter.MetricFilter</filter-class>
     </filter>
 
     <filter-mapping>

spring-boot-modules/spring-boot-actuator/src/test/java/com/baeldung/metrics/MetricsApplicationIntegrationTest.java

@@ -0,0 +1,64 @@
+package com.baeldung.metrics;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.test.context.ActiveProfiles;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.awaitility.Awaitility.await;
+import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment.RANDOM_PORT;
+
+@SpringBootTest(
+  classes = MetricsApplication.class,
+  webEnvironment = RANDOM_PORT,
+  properties = {"fixedDelay.in.milliseconds=2000"}
+)
+@ActiveProfiles("metrics")
+class MetricsApplicationIntegrationTest {
+
+    @Autowired
+    private TestRestTemplate restTemplate;
+
+    @Test
+    void givenStatuses_WhenScheduledMethodExecuted_ExpectCountsAreAggregated() {
+        restTemplate.getForObject("/metrics/metric/notFound", String.class);
+        restTemplate.getForObject("/metrics/metric", String.class);
+
+        await().untilAsserted(() -> {
+            Object[][] statusCounts = restTemplate.getForObject("/metrics/metric-graph-data", Object[][].class);
+
+            assertThat(statusCounts[0]).contains("counter.status.200", "counter.status.404");
+
+            List<Integer> requestCounts = getRequestCounts(statusCounts);
+            verify404RequestFrom(requestCounts);
+            verify200RequestsFrom(requestCounts);
+        });
+    }
+
+    private static void verify200RequestsFrom(List<Integer> requestCounts) {
+        assertThat(requestCounts.size()).isGreaterThan(1);
+    }
+
+    private static void verify404RequestFrom(List<Integer> requestCounts) {
+        assertThat(requestCounts).contains(1);
+    }
+
+    private static List<Integer> getRequestCounts(Object[][] statusCounts) {
+        List<Integer> requestCounts = new ArrayList<>();
+        for (int i = 1; i < statusCounts.length; i++) {
+            for (int j = 1; j < statusCounts[i].length; j++) {
+                Integer count = (Integer) statusCounts[i][j];
+                if (count >= 1) {
+                    requestCounts.add(count);
+                }
+            }
+        }
+        return requestCounts;
+    }
+
+}

spring-web-modules/spring-rest-testing/README.md

@@ -11,7 +11,6 @@ The "Learn Spring Security" Classes: http://github.learnspringsecurity.com
 ### Relevant Articles: 
 
 - [Integration Testing with the Maven Cargo plugin](https://www.baeldung.com/integration-testing-with-the-maven-cargo-plugin)
-- [Metrics for your Spring REST API](https://www.baeldung.com/spring-rest-api-metrics)
 - [Testing Exceptions with Spring MockMvc](https://www.baeldung.com/spring-mvc-test-exceptions)
 
 ### Build the Project

spring-web-modules/spring-rest-testing/pom.xml

@@ -21,19 +21,10 @@
             <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.aspectj</groupId>
             <artifactId>aspectjweaver</artifactId>
         </dependency>
-        <dependency>
-            <groupId>org.apache.tomcat.embed</groupId>
-            <artifactId>tomcat-embed-jasper</artifactId>
-            <scope>provided</scope>
-        </dependency>
         <!-- Spring -->
         <dependency>
             <groupId>org.springframework</groupId>
@@ -69,14 +60,6 @@
             <groupId>org.springframework</groupId>
             <artifactId>spring-expression</artifactId>
         </dependency>
-        <dependency>
-            <groupId>org.springframework</groupId>
-            <artifactId>spring-web</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.springframework</groupId>
-            <artifactId>spring-webmvc</artifactId>
-        </dependency>
         <dependency>
             <groupId>org.springframework.data</groupId>
             <artifactId>spring-data-commons</artifactId>
@@ -137,17 +120,6 @@
             <groupId>net.bytebuddy</groupId>
             <artifactId>byte-buddy</artifactId>
         </dependency>
-        <!-- web -->
-        <dependency>
-            <groupId>javax.servlet</groupId>
-            <artifactId>javax.servlet-api</artifactId>
-            <scope>provided</scope>
-        </dependency>
-        <dependency>
-            <groupId>javax.servlet</groupId>
-            <artifactId>jstl</artifactId>
-            <scope>runtime</scope>
-        </dependency>
         <!-- marshalling -->
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>

spring-web-modules/spring-rest-testing/src/main/java/com/baeldung/spring/Application.java

@@ -1,38 +1,19 @@
 package com.baeldung.spring;
 
-import javax.servlet.ServletContext;
-import javax.servlet.ServletException;
-
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
-import org.springframework.boot.builder.SpringApplicationBuilder;
-import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
 import org.springframework.context.annotation.ComponentScan;
-import org.springframework.scheduling.annotation.EnableScheduling;
-import org.springframework.web.context.request.RequestContextListener;
 
 /**
  * Main Application Class - uses Spring Boot. Just run this as a normal Java
  * class to run up a Jetty Server (on http://localhost:8082/spring-rest-full)
  *
  */
-@EnableScheduling
 @EnableAutoConfiguration
 @ComponentScan("com.baeldung")
 @SpringBootApplication
-public class Application extends SpringBootServletInitializer {
+public class Application {
-
-    @Override
-    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
-        return application.sources(Application.class);
-    }
-
-    @Override
-    public void onStartup(ServletContext sc) throws ServletException {
-        // Manages the lifecycle of the root application context
-        sc.addListener(new RequestContextListener());
-    }
 
     public static void main(final String[] args) {
         SpringApplication.run(Application.class, args);

spring-web-modules/spring-rest-testing/src/main/java/com/baeldung/web/controller/RootController.java

@@ -1,52 +0,0 @@
-package com.baeldung.web.controller;
-
-import java.util.Map;
-
-import com.baeldung.web.metric.IActuatorMetricService;
-import com.baeldung.web.metric.IMetricService;
-import org.springframework.beans.factory.annotation.Autowired;
-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;
-
-@Controller
-@RequestMapping(value = "/auth/")
-public class RootController {
-
-    @Autowired
-    private IMetricService metricService;
-
-    @Autowired
-    private IActuatorMetricService actMetricService;
-
-    public RootController() {
-        super();
-    }
-
-    // API
-
-    @RequestMapping(value = "/metric", method = RequestMethod.GET)
-    @ResponseBody
-    public Map getMetric() {
-        return metricService.getFullMetric();
-    }
-
-    @RequestMapping(value = "/status-metric", method = RequestMethod.GET)
-    @ResponseBody
-    public Map getStatusMetric() {
-        return metricService.getStatusMetric();
-    }
-
-    @RequestMapping(value = "/metric-graph", method = RequestMethod.GET)
-    @ResponseBody
-    public Object[][] drawMetric() {
-        final Object[][] result = metricService.getGraphData();
-        for (int i = 1; i < result[0].length; i++) {
-            result[0][i] = result[0][i].toString();
-        }
-        return result;
-    }
-
-
-}

spring-web-modules/spring-rest-testing/src/main/java/com/baeldung/web/metric/IActuatorMetricService.java

@@ -1,5 +0,0 @@
-package com.baeldung.web.metric;
-
-public interface IActuatorMetricService {
-    Object[][] getGraphData();
-}

spring-web-modules/spring-rest-testing/src/main/java/com/baeldung/web/metric/ICustomActuatorMetricService.java

@@ -1,8 +0,0 @@
-package com.baeldung.web.metric;
-
-public interface ICustomActuatorMetricService {
-
-    void increaseCount(final int status);
-
-    Object[][] getGraphData();
-}

spring-web-modules/spring-rest-testing/src/main/java/com/baeldung/web/metric/IMetricService.java

@@ -1,14 +0,0 @@
-package com.baeldung.web.metric;
-
-import java.util.Map;
-
-public interface IMetricService {
-
-    void increaseCount(final String request, final int status);
-
-    Map getFullMetric();
-
-    Map getStatusMetric();
-
-    Object[][] getGraphData();
-}

spring-web-modules/spring-rest-testing/src/main/java/com/baeldung/web/metric/MetricService.java

@@ -1,122 +0,0 @@
-package com.baeldung.web.metric;
-
-import java.text.SimpleDateFormat;
-import java.util.Date;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.Set;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.ConcurrentMap;
-
-import org.springframework.stereotype.Service;
-
-@Service
-public class MetricService implements IMetricService {
-
-    private ConcurrentMap<String, ConcurrentHashMap<Integer, Integer>> metricMap;
-    private ConcurrentMap<Integer, Integer> statusMetric;
-    private ConcurrentMap<String, ConcurrentHashMap<Integer, Integer>> timeMap;
-    private static final SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm");
-
-    public MetricService() {
-        super();
-        metricMap = new ConcurrentHashMap<String, ConcurrentHashMap<Integer, Integer>>();
-        statusMetric = new ConcurrentHashMap<Integer, Integer>();
-        timeMap = new ConcurrentHashMap<String, ConcurrentHashMap<Integer, Integer>>();
-    }
-
-    // API
-
-    @Override
-    public void increaseCount(final String request, final int status) {
-        increaseMainMetric(request, status);
-        increaseStatusMetric(status);
-        updateTimeMap(status);
-    }
-
-    @Override
-    public Map getFullMetric() {
-        return metricMap;
-    }
-
-    @Override
-    public Map getStatusMetric() {
-        return statusMetric;
-    }
-
-    @Override
-    public Object[][] getGraphData() {
-        final int colCount = statusMetric.keySet().size() + 1;
-        final Set<Integer> allStatus = statusMetric.keySet();
-        final int rowCount = timeMap.keySet().size() + 1;
-
-        final Object[][] result = new Object[rowCount][colCount];
-        result[0][0] = "Time";
-
-        int j = 1;
-        for (final int status : allStatus) {
-            result[0][j] = status;
-            j++;
-        }
-        int i = 1;
-        ConcurrentMap<Integer, Integer> tempMap;
-        for (final Entry<String, ConcurrentHashMap<Integer, Integer>> entry : timeMap.entrySet()) {
-            result[i][0] = entry.getKey();
-            tempMap = entry.getValue();
-            for (j = 1; j < colCount; j++) {
-                result[i][j] = tempMap.get(result[0][j]);
-                if (result[i][j] == null) {
-                    result[i][j] = 0;
-                }
-            }
-            i++;
-        }
-
-        return result;
-    }
-
-    // NON-API
-
-    private void increaseMainMetric(final String request, final int status) {
-        ConcurrentHashMap<Integer, Integer> statusMap = metricMap.get(request);
-        if (statusMap == null) {
-            statusMap = new ConcurrentHashMap<Integer, Integer>();
-        }
-
-        Integer count = statusMap.get(status);
-        if (count == null) {
-            count = 1;
-        } else {
-            count++;
-        }
-        statusMap.put(status, count);
-        metricMap.put(request, statusMap);
-    }
-
-    private void increaseStatusMetric(final int status) {
-        final Integer statusCount = statusMetric.get(status);
-        if (statusCount == null) {
-            statusMetric.put(status, 1);
-        } else {
-            statusMetric.put(status, statusCount + 1);
-        }
-    }
-
-    private void updateTimeMap(final int status) {
-        final String time = dateFormat.format(new Date());
-        ConcurrentHashMap<Integer, Integer> statusMap = timeMap.get(time);
-        if (statusMap == null) {
-            statusMap = new ConcurrentHashMap<Integer, Integer>();
-        }
-
-        Integer count = statusMap.get(status);
-        if (count == null) {
-            count = 1;
-        } else {
-            count++;
-        }
-        statusMap.put(status, count);
-        timeMap.put(time, statusMap);
-    }
-
-}

spring-web-modules/spring-rest-testing/src/main/resources/application.properties

@@ -1,3 +1,2 @@
 server.port=8082
 server.servlet.context-path=/spring-rest-full
-endpoints.metrics.enabled=true