DruidDataSource add keepAlive support.

src/test/java/com/alibaba/druid/bvt/pool/KeepAliveTest.java

@@ -0,0 +1,53 @@
+package com.alibaba.druid.bvt.pool;
+
+import com.alibaba.druid.pool.DruidDataSource;
+import com.alibaba.druid.util.JdbcUtils;
+import junit.framework.TestCase;
+
+import java.sql.Connection;
+import java.util.Properties;
+
+/**
+ * Created by wenshao on 21/01/2017.
+ */
+public class KeepAliveTest extends TestCase {
+    private DruidDataSource dataSource;
+
+    protected void setUp() throws Exception {
+        dataSource = new DruidDataSource();
+        dataSource.setUrl("jdbc:mock:x1");
+        dataSource.setPoolPreparedStatements(true);
+        dataSource.setMinIdle(10);
+        dataSource.setMaxActive(20);
+//        dataSource.setMinEvictableIdleTimeMillis(30000);
+//        dataSource.setMaxEvictableIdleTimeMillis(30000);
+        dataSource.setTimeBetweenEvictionRunsMillis(10);
+        dataSource.setFilters("log4j");
+        dataSource.setValidationQuery("select 1");
+
+        Properties properties = new Properties();
+        properties.put("druid.keepAlive", "true");
+        dataSource.configFromPropety(properties);
+    }
+
+    protected void tearDown() throws Exception {
+        JdbcUtils.close(dataSource);
+    }
+
+    public void test_keepAlive() throws Exception {
+        assertTrue(dataSource.isKeepAlive());
+
+        Connection[] connections = new Connection[dataSource.getMaxActive()];
+        for (int i = 0; i < connections.length; ++i) {
+            connections[i] = dataSource.getConnection();
+        }
+        for (int i = 0; i < connections.length; ++i) {
+            connections[i].close();
+        }
+        // assertEquals(dataSource.getMaxActive(), dataSource.getPoolingCount());
+
+
+
+        // Thread.sleep(1000 * 1000);
+    }
+}