DataSource连接失败常见异常捕获

捕获SQLException异常，并对常见的异常进行特殊处理：

private static Boolean sqlTest(DataSource dataSource) {try {dataSource.setLoginTimeout(5);dataSource.getConnection().getClientInfo();}catch (SQLException e) {if(e.getCause() instanceof CJCommunicationsException){//S100CJCommunicationsException cjCommunicationsException = (CJCommunicationsException)e.getCause();System.out.println("错误码："+cjCommunicationsException.getSQLState());System.out.println("错误信息："+cjCommunicationsException.getMessage());}else if(e.getCause() instanceof CJException){//42000，28000CJException cjException = (CJException)e.getCause();System.out.println("错误码："+cjException.getSQLState());System.out.println("错误信息："+cjException.getMessage());}e.printStackTrace();return false;}return true;}