fix: set timezone 'Asia/Shanghai' bug (#261)

Author: sheyanjie-qq

src/main/java/com/taosdata/jdbc/rs/ConnectionParam.java

@@ -344,10 +344,8 @@ public static ConnectionParam getParamWs(Properties perperties) throws SQLExcept
         try {
             ZoneId zoneId = ZoneId.of(connectionParam.getTz());
             ZoneId defaultZoneId = ZoneId.systemDefault();
-            if (!StringUtils.isEmpty(connectionParam.getTz()) && defaultZoneId.equals(zoneId)){
-                //  for performance, if the time zone is the same as the system default time zone, we ignore it
-                connectionParam.setTz("");
-            } else {
+            if (!defaultZoneId.equals(zoneId)){
+                //  Only set the time zone if it differs from the system default
                 connectionParam.setZoneId(zoneId);
             }
         } catch (DateTimeException e) {

src/test/java/com/taosdata/jdbc/ws/WSTimeZoneTest2.java

@@ -0,0 +1,44 @@
+package com.taosdata.jdbc.ws;
+
+import com.taosdata.jdbc.TSDBDriver;
+import com.taosdata.jdbc.annotation.TestTarget;
+import com.taosdata.jdbc.utils.DateTimeUtils;
+import com.taosdata.jdbc.utils.SpecifyAddress;
+import com.taosdata.jdbc.utils.TestUtils;
+import org.junit.After;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.sql.Date;
+import java.sql.*;
+import java.time.*;
+import java.time.temporal.ChronoUnit;
+import java.util.*;
+
+@TestTarget(alias = "websocket timezon test", author = "sheyj", version = "3.7.0")
+public class WSTimeZoneTest2 {
+
+    private static final String host = "127.0.0.1";
+    private static final int port = 6041;
+
+
+
+    @Test
+    public void UTC8Test() throws SQLException {
+        String url = SpecifyAddress.getInstance().getRestWithoutUrl();
+        if (url == null) {
+            url = "jdbc:TAOS-WS://" + host + ":" + port + "/?user=root&password=taosdata";
+        } else {
+            url += "?user=root&password=taosdata";
+        }
+        Properties properties = new Properties();
+        properties.setProperty(TSDBDriver.PROPERTY_KEY_TIME_ZONE, "Asia/Shanghai");
+        try ( Connection connection = DriverManager.getConnection(url, properties)) {
+            WSConnection wsConnection = (WSConnection) connection;
+            Assert.assertEquals("Asia/Shanghai", wsConnection.getParam().getTz());
+        }
+    }
+}