change

src/connector/jdbc/src/main/java/com/taosdata/jdbc/AbstractConnection.java

@@ -311,13 +311,17 @@ public abstract class AbstractConnection extends WrapperImpl implements Connecti
 
         boolean status = false;
         try {
-            status = future.get(timeout, TimeUnit.MILLISECONDS);
+            if (timeout == 0)
+                status = future.get();
+            else
+                status = future.get(timeout, TimeUnit.SECONDS);
         } catch (InterruptedException e) {
             e.printStackTrace();
         } catch (ExecutionException e) {
             e.printStackTrace();
         } catch (TimeoutException e) {
             future.cancel(true);
+            status = false;
         } finally {
             executor.shutdownNow();
         }

src/connector/jdbc/src/test/java/com/taosdata/jdbc/TSDBConnectionTest.java

@@ -194,7 +194,7 @@ public class TSDBConnectionTest {
 
     @Test
     public void isValid() throws SQLException {
-        Assert.assertTrue(conn.isValid(1000));
+        Assert.assertTrue(conn.isValid(5));
         conn.isValid(0);
     }