Change such that when testing the connection on return due to error it skips trimming connections

That is, when returning a connection that has errored and it tests the connection to ensure it is valid it WAS also trimming the connection pool and with this change it will not perform that trim.

- Renames checkDataSource() -> heartBeat()
- Splits out testConnection() to a separate method
- Only call testConnection() in case of returning connection with forceClose (no trim here now)

Author: rbygrave

ebean-datasource/src/main/java/io/ebean/datasource/pool/ConnectionPool.java

@@ -111,8 +111,8 @@ final class ConnectionPool implements DataSourcePool {
     this.pstmtCacheSize = params.getPstmtCacheSize();
     this.minConnections = params.getMinConnections();
     this.maxConnections = params.getMaxConnections();
-    this.waitTimeoutMillis = params.getWaitTimeoutMillis();
     this.heartbeatsql = params.getHeartbeatSql();
+    this.waitTimeoutMillis = params.getWaitTimeoutMillis();
     this.heartbeatFreqSecs = params.getHeartbeatFreqSecs();
     this.heartbeatTimeoutSeconds = params.getHeartbeatTimeoutSeconds();
     this.trimPoolFreqMillis = 1000L * params.getTrimPoolFreqSecs();
@@ -151,10 +151,10 @@ void pstmtCacheMetrics(PstmtCache pstmtCache) {
     pscRem.add(pstmtCache.removeCount());
   }
 
-  class HeartBeatRunnable extends TimerTask {
+  final class HeartBeatRunnable extends TimerTask {
     @Override
     public void run() {
-      checkDataSource();
+      heartBeat();
     }
   }
 
@@ -372,8 +372,12 @@ private void trimIdleConnections() {
    * This is called by the HeartbeatRunnable which should be scheduled to
    * run periodically (every heartbeatFreqSecs seconds).
    */
-  private void checkDataSource() {
+  private void heartBeat() {
     trimIdleConnections();
+    testConnection();
+  }
+
+  private void testConnection() {
     Connection conn = null;
     try {
       // Get a connection from the pool and test it
@@ -561,7 +565,7 @@ private void returnTheConnection(PooledConnection pooledConnection, boolean forc
     queue.returnPooledConnection(pooledConnection, forceClose);
     if (forceClose) {
       // Got a bad connection so check the pool
-      checkDataSource();
+      testConnection();
     }
   }