关于sql developer无法连接的问题

两种方式：sid/服务名

1. 检查环境变量：TNS文件的路径是否正确，该路径下是否有tnsnames.ora和listener.ora
   
   如果没有，通过菜单栏Net Configuration Assistant生成
   
   
2. 检查上述两种文件内容，文件内容：
   tnsnames.ora

# tnsnames.ora Network Configuration File: E:\app\LENOVO\product\11.2.0\dbhome_1\admin\tnsnames.ora
# Generated by Oracle configuration tools.

ORACLR_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    )
    (CONNECT_DATA =
      (SID = CLRExtProc)
      (PRESENTATION = RO)
    )
  )
ORCL =
  (DESCRIPTION = 
    (ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521))
    (CONNECT_DATA = 
	  (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )
  test-name =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = intdbnew)
    )
  )

listener.ora

# listener.ora Network Configuration File: E:\app\LENOVO\product\11.2.0\dbhome_1\admin\listener.ora
# Generated by Oracle configuration tools.

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = ORCL)
      (ORACLE_HOME = E:\app\LENOVO\product\11.2.0\dbhome_1)
      (PROGRAM = extproc)
      (ENVS = "EXTPROC_DLLS=ONLY:E:\app\LENOVO\product\11.2.0\dbhome_1\bin\oraclr11.dll")
    )
	(SID_DESC =
	  (GLOBAL_DBNAME = ORCL)
	  (ORACLE_HOME = E:\app\LENOVO\product\11.2.0\dbhome_1)
	  (SID_NAME = ORCL)
  )
)
LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521))
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    )
  )

ADR_BASE_LISTENER = E:\app\LENOVO

着重检查HOST,POST,SERVICE_NAME,SID_NAME
HOST填写服务器ip地址，一般可填本机127.0.0.1，端口号一般1521，服务名要与sql developer连接页面的服务名称一致，SID同样也需保持一致。

最后，遇到问题不要慌。
实在不行找男朋友帮忙。