Re: Oracle 9i connection error

Hi,

1. Can machine b see the db server machine? (sqlplus from machine b to db server as a test.)
2. Did you change the dbhost parameter in the connect string for the servlet?
3. Are you using the thin driver?

Cindy

Joyce wrote:

> Hi,
>
> I have a database connection problem. Please tell me what's wrong.
>
> My applet-servlet program demostrates applet-servlet-database
> communication.Servlet program connects database (Oracle 9i), retrieves
> records from database and sends records to applet.
>
> They work properly, if applet program, servlet program and database
> are in
> the same machine A. However, error occurs when applet program and
> servlet
> program are moved to another machine B. That is, programs and database
> are located in different machine. Error message is as follows:
>
> java.sql.SQLException: Io exception: The Network Adapter could not
> establish
> the connection
> at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:180)
> at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:222)
> at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:335)
> at oracle.jdbc.driver.OracleConnection.<init>(OracleConnection.java:361)
> at
> oracle.jdbc.driver.OracleDriver.getConnectionInstance(OracleDriver.java:442)
> at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:321)
> at java.sql.DriverManager.getConnection(DriverManager.java:517)
> at java.sql.DriverManager.getConnection(DriverManager.java:177)
> at StoreServlet.findAllBookUI(StoreServlet.java:292)
> at StoreServlet.doGet(StoreServlet.java:234)
> at javax.servlet.http.HttpServlet.service(HttpServlet.java:740)
> at javax.servlet.http.HttpServlet.service(HttpServlet.java:853)
> at
> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(Application
> FilterChain.java:247)
> at
> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterCh
> ain.java:193)
> at
> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.ja
> va:243)
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 66)
> at
> org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
> at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
> at
> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.ja
> va:201)
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 66)
> at
> org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
> at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
> at
> org.apache.catalina.core.StandardContext.invoke(StandardContext.java:2344)
> at
> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164
> )
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 66)
> at
> org.apache.catalina.valves.ErrorDispatcherValve.invoke(ErrorDispatcherValve.
> java:170)
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 64)
> at
> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:170
> )
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 64)
> at
> org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:462)
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 64)
> at
> org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
> at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
> at
> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java
> :163)
> at
> org.apache.catalina.core.StandardPipeline.invokeNext(StandardPipeline.java:5
> 66)
> at
> org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:472)
> at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:943)
> at
> org.apache.catalina.connector.http.HttpProcessor.process(HttpProcessor.java:
> 1011)
> at
> org.apache.catalina.connector.http.HttpProcessor.run(HttpProcessor.java:1106
> )
> at java.lang.Thread.run(Thread.java:484)
>
> The message indicates that the Servlet program cannot establish a
> connection to the database. I'm quite sure that the Oracle JDBC 9i
> library is installed in machine B and its URL is included in the
> classpath.
>
> Do you have any idea ?
>
> Thanks in advanced.
>
> Best Regards,
> Joyce
Received on Thu Apr 11 2002 - 12:10:38 CDT