Add counter interceptor

Author: edysegura

src/main/java/br/com/spring/restful/component/TriggerCounter.java

@@ -0,0 +1,27 @@
+package br.com.spring.restful.component;
+
+import java.util.HashMap;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class TriggerCounter {
+
+  private final HashMap<String, Integer> counter = new HashMap<String, Integer>();
+
+  public void increment(String api) {
+    Integer value = counter.get(api);
+    if (value != null) {
+      value++;
+    }
+    else {
+      value = 1;
+    }
+    counter.put(api, value);
+  }
+
+  public HashMap<String, Integer> getCounter() {
+    return counter;
+  }
+
+}

src/main/java/br/com/spring/restful/config/InterceptorConfig.java

@@ -0,0 +1,23 @@
+package br.com.spring.restful.config;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+import br.com.spring.restful.interceptor.CounterInterceptor;
+
+@Configuration
+public class InterceptorConfig implements WebMvcConfigurer {
+
+  @Autowired
+  private CounterInterceptor counterInterceptor;
+
+  @Override
+  public void addInterceptors(InterceptorRegistry registry) {
+    registry.addInterceptor(counterInterceptor);
+    // TODO add token interceptor
+    // TODO exception handler
+  }
+
+}

src/main/java/br/com/spring/restful/controllers/MainController.java

@@ -1,15 +1,27 @@
 package br.com.spring.restful.controllers;
 
+import java.util.Map;
+
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
 
+import br.com.spring.restful.component.TriggerCounter;
 
 @RestController
 public class MainController {
 
-  @GetMapping(value="/")
+  @Autowired
+  TriggerCounter counter;
+
+  @GetMapping(value = "/")
   public String index() {
-      return "Welcome to Todo List REST API!";
+    return "Welcome to Todo List REST API!";
+  }
+
+  @GetMapping(value = "/counters")
+  public Map<String, Integer> getCounters() {
+    return counter.getCounter();
   }
 
 }

src/main/java/br/com/spring/restful/interceptor/CounterInterceptor.java

@@ -0,0 +1,25 @@
+package br.com.spring.restful.interceptor;
+
+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.servlet.HandlerInterceptor;
+
+import br.com.spring.restful.component.TriggerCounter;
+
+@Component
+public class CounterInterceptor implements HandlerInterceptor {
+
+  @Autowired
+  TriggerCounter triggerCounter;
+
+  @Override
+  public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
+      throws Exception {
+    triggerCounter.increment(request.getMethod() + ":" + request.getRequestURI());
+    return HandlerInterceptor.super.preHandle(request, response, handler);
+  }
+
+}