Allow setting the dataSource directly on the HikariConfig.

src/main/java/com/zaxxer/hikari/HikariConfig.java

@@ -24,6 +24,8 @@ import java.sql.Connection;
 import java.util.Properties;
 import java.util.concurrent.TimeUnit;
 
+import javax.sql.DataSource;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -60,6 +62,7 @@ public final class HikariConfig implements HikariConfigMBean
     private boolean isJdbc4connectionTest;
     private boolean isAutoCommit;
     private Properties dataSourceProperties;
+    private DataSource dataSource;
 
     /**
      * Default constructor
@@ -212,6 +215,16 @@ public final class HikariConfig implements HikariConfigMBean
         }
     }
 
+    public DataSource getDataSource()
+    {
+        return dataSource;
+    }
+
+    public void setDataSource(DataSource dataSource)
+    {
+        this.dataSource = dataSource;
+    }
+
     public String getDataSourceClassName()
     {
         return dataSourceClassName;
@@ -398,6 +411,12 @@ public final class HikariConfig implements HikariConfigMBean
         	connectionTimeout = CONNECTION_TIMEOUT;
         }
 
+        if (dataSource == null && dataSourceClassName == null)
+        {
+            logger.error("one of either dataSource or dataSourceClassName must be specified");
+            throw new IllegalStateException("one of either dataSource or dataSourceClassName must be specified");
+        }
+
         if (idleTimeout < 0)
         {
             logger.error("idleTimeout cannot be negative.");

src/main/java/com/zaxxer/hikari/HikariPool.java

@@ -82,16 +82,23 @@ public final class HikariPool implements HikariPoolMBean
         this.transactionIsolation = configuration.getTransactionIsolation();
         this.debug = LOGGER.isDebugEnabled();
 
-        String dsClassName = configuration.getDataSourceClassName();
-        try
+        if (configuration.getDataSource() == null)
         {
-            Class<?> clazz = this.getClass().getClassLoader().loadClass(dsClassName);
-            this.dataSource = (DataSource) clazz.newInstance();
-            PropertyBeanSetter.setTargetFromProperties(dataSource, configuration.getDataSourceProperties());
+            String dsClassName = configuration.getDataSourceClassName();
+            try
+            {
+                Class<?> clazz = this.getClass().getClassLoader().loadClass(dsClassName);
+                this.dataSource = (DataSource) clazz.newInstance();
+                PropertyBeanSetter.setTargetFromProperties(dataSource, configuration.getDataSourceProperties());
+            }
+            catch (Exception e)
+            {
+                throw new RuntimeException("Could not create datasource instance: " + dsClassName, e);
+            }
         }
-        catch (Exception e)
+        else
         {
-            throw new RuntimeException("Could not create datasource instance: " + dsClassName, e);
+            this.dataSource = configuration.getDataSource();
         }
 
         HikariMBeanElf.registerMBeans(configuration, this);