Merge pull request #122 from NitorCreations/registerHikariPoolToMetri…

…cRegistry

Register hikari pool to MetricRegistry if MetricRegistry is on classpath

nflow-engine/src/main/java/com/nitorcreations/nflow/engine/internal/storage/db/DatabaseConfiguration.java

@@ -6,6 +6,8 @@
 import javax.sql.DataSource;
 
 import org.slf4j.Logger;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Scope;
 import org.springframework.core.env.Environment;
@@ -29,7 +31,7 @@ protected DatabaseConfiguration(String dbType) {
 
   @Bean
   @NFlow
-  public DataSource nflowDatasource(Environment env) {
+  public DataSource nflowDatasource(Environment env, BeanFactory appCtx) {
     String url = property(env, "url");
     logger.info("Database connection to {} using {}", dbType, url);
     HikariConfig config = new HikariConfig();
@@ -41,9 +43,22 @@ public DataSource nflowDatasource(Environment env) {
     config.setMaximumPoolSize(property(env, "max_pool_size", Integer.class));
     config.setIdleTimeout(property(env, "idle_timeout_seconds", Integer.class) * 1000);
     config.setAutoCommit(true);
+    setMetricRegistryIfBeanFoundOnClassPath(config, appCtx);
     return new HikariDataSource(config);
   }
 
+  private void setMetricRegistryIfBeanFoundOnClassPath(HikariConfig config, BeanFactory appCtx) {
+    try {
+      Class<?> metricClass = Class.forName("com.codahale.metrics.MetricRegistry");
+      Object metricRegistry = appCtx.getBean(metricClass);
+      if (metricRegistry != null) {
+        config.setMetricRegistry(metricRegistry);
+      }
+    } catch (ClassNotFoundException | NoSuchBeanDefinitionException e) {
+      // ignored - metrics is an optional dependency
+    }
+  }
+
   @Bean
   @NFlow
   @Scope(SCOPE_PROTOTYPE)