JDBC连接sqlserver2008?报错

一个简单的jdbc创建连接sqlserver服务，代码如下，为什么执行到创建连接成功打印connected...，就卡住不动，也没有报错，就不往向下执行了呢？？

求各位大神帮忙看看。。。，非常感谢。

Connection conn = null;
		Statement statement = null;
		ResultSet rs = null;
      try {
         Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
         conn = DriverManager.getConnection(db_connect_string,
                  db_userid, db_password);
         System.out.println("#### connected...");
         statement = conn.createStatement();
         String queryString = "select * from sysobjects where type='u'";
         rs = statement.executeQuery(queryString);
         System.out.println("#### executeQuery...");
         while (rs.next()) {
            System.out.println(rs.getString(1));
         }
         
      } catch (Exception e) {
         e.printStackTrace();
      }finally{
    	  try {
			if(!rs.isClosed())rs.close();
			if(!statement.isClosed())statement.close();
			if(!conn.isClosed())conn.close();
		} catch (SQLException e) {
			e.printStackTrace();
		}
    		
      }