大家来帮帮我....

jsp 连 oracle9i
早上用的好好的，忽然出现如下错误..
java.sql.SQLException: Io 异常: The Network Adapter could not establish the connection
oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:134)
oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:179)
oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:333)
oracle.jdbc.driver.OracleConnection.<init>(OracleConnection.java:404)
oracle.jdbc.driver.OracleDriver.getConnectionInstance(OracleDriver.java:468)
oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:314)
java.sql.DriverManager.getConnection(Unknown Source)
java.sql.DriverManager.getConnection(Unknown Source)
org.apache.jsp.cba_jsp._jspService(cba_jsp.java:96)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:332)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
早上还可以连接数据库的，然后做了个上传文件后。测试了几次，就成这样了。连数据库都连不上，大家帮帮我，看看怎么回事！