我用的 
jdbc:oracle:thin:@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=xxx.xxx.xxx.xxx)(PORT=1521))(ADDRESS=(PROTOCOL=TCP)(HOST=xxx.xxx.xxx.xxx)(PORT=1521))(LOAD_BALANCE=yes))(CONNECT_DATA=(SERVICE_NAME=xxx))) 有时会出现javax.servlet.ServletException: Io 异常: The Network Adapter could not establish the connection 连接时,问题出现的情况几乎是1/2现在我怎么做单机连接?字串怎么写?