HANA studio 连接 hanadb总连不上，求救

以下是error log, 搞了一晚上了也不行，俺是个初学者,不知道为什么总报“jdbc驱动”问题，求救各位大神。。


com.sap.ndb.studio.jdbc.JDBCConnectionStatus: Database connection is not available. See error log for details.

at com.sap.ndb.studio.jdbc.JDBCPlugin.createConnection(JDBCPlugin.java:332)

at com.sap.ndb.studio.navigator.wizards.newsapsystem.NewSAPSystemWizard$1$1.call(NewSAPSystemWizard.java:226)

at com.sap.ndb.studio.navigator.wizards.newsapsystem.NewSAPSystemWizard$1$1.call(NewSAPSystemWizard.java:1)

at java.util.concurrent.FutureTask.run(FutureTask.java:262)

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)

at java.lang.Thread.run(Thread.java:744)
Caused by: com.sap.db.jdbc.exceptions.JDBCDriverException: SAP DBTech JDBC: Cannot connect to jdbc:sap://192.168.61.4:30015 [Cannot connect to host 192.168.61.4:30015 [Connection refused: connect], -813.].

at com.sap.db.jdbc.exceptions.SQLExceptionSapDB.createException(SQLExceptionSapDB.java:219)

at com.sap.db.jdbc.exceptions.SQLExceptionSapDB.createException(SQLExceptionSapDB.java:203)

at com.sap.db.jdbc.exceptions.SQLExceptionSapDB.generateDatabaseException(SQLExceptionSapDB.java:186)

at com.sap.db.jdbc.Driver.connect(Driver.java:238)

at com.sap.ndb.studio.jdbc.JDBCPlugin$3.run(JDBCPlugin.java:653)