Can not Start the database server because of the host name changed

cd $ORACLE_HOME/network/admin

vi listener.ora

将××××改成修改后的host name

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
      (ADDRESS = (PROTOCOL = TCP)(HOST = ****)(PORT = 1521))
    )
  )

ADR_BASE_LISTENER = /app/oracle/database

 vi tnsnames.ora

将××××改成修改后的host name

orcl =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = ×××××)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )