我尝试使用以下代码连接到数据库
Class.forName("com.mysql.cj.jdbc.Driver");
Connection con=DriverManager.getConnection(DBurl,sUserName,sPassword);
工作正常，但是突然我开始遇到下面提到的异常。（我能够从终端连接数据库）
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:836)
at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:456)
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:246)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:197)
at java.sql.DriverManager.getConnection(DriverManager.java:664)
at java.sql.DriverManager.getConnection(DriverManager.java:247)
at Utility.DBFunctions.dbConnection(DBFunctions.java:48)
at Utility.DBFunctions.executeQuery(DBFunctions.java:75)
at DriverScript.driverscript.ExecuteTest(driverscript.java:137)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:133)
at org.testng.internal.TestInvoker.invokeMethod(TestInvoker.java:584)
at org.testng.internal.TestInvoker.invokeTestMethod(TestInvoker.java:172)
at org.testng.internal.MethodRunner.runInSequence(MethodRunner.java:46)
at org.testng.internal.TestInvoker$MethodInvocationAgent.invoke(TestInvoker.java:804)
at org.testng.internal.TestInvoker.invokeTestMethods(TestInvoker.java:145)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:146)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:128)
at java.util.ArrayList.forEach(ArrayList.java:1257)
at org.testng.TestRunner.privateRun(TestRunner.java:770)
at org.testng.TestRunner.run(TestRunner.java:591)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:402)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:396)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:355)
at org.testng.SuiteRunner.run(SuiteRunner.java:304)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:53)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:96)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1180)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1102)
at org.testng.TestNG.runSuites(TestNG.java:1032)
at org.testng.TestNG.run(TestNG.java:1000)
at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:115)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:251)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:77)
有人可以帮助我解决此问题吗？预先感谢。