Java链接数据库时，运行一天后时而会报java.sql.SQLException: Io 异常: Connection refused(DESCRIPTION=(TMP=)(VSNNUM=186
646784)(ERR=12518)(ERROR_STACK=(ERROR=(CODE=12518)(EMFI=4))(ERROR=(CODE=12560)(E
MFI=4))))
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:134)
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:179)
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:333)
at oracle.jdbc.driver.OracleConnection.<init>(OracleConnection.java:404)
at oracle.jdbc.driver.OracleDriver.getConnectionInstance(OracleDriver.ja
va:468)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:314)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at com.huyongke.utility.DBConn.createConnection(DBConn.java:238)
at com.huyongke.utility.DBConnPool.getConnection(DBConnPool.java:78)
at com.huyongke.utility.ExeSQL.execSQL(ExeSQL.java:894)
错误，
请问哪位大侠见过啊，不吝赐教啊。
------解决思路----------------------
http://blog.csdn.net/dingherry/article/details/5728280