JDBC Server Programmer's Reference

Note: Previous versions of the jdbcServer.jar file must not appear in your CLASSPATH nor in
/usr/tandem/java/jre/lib/ext. Any old versions of the jdbcServer.jar file residing in the ext
directory must be moved to another directory. If you leave a previous version of this jar file in
/usr/tandem/java/jre/lib/ext, the Java Virtual Machine will find the old jar file before it finds the
new jar file in your CLASSPATH. If another version of the jdbcServer.jar file exists in your CLASSPATH
or in the ext directory, you may receive an exception indicating either that stubs cannot be found or that a
marshaling/unmarshaling error has occurred.
Troubleshooting
If you have problems communicating with the JDBC Server, perform the following steps to verify that you are using the
correct versions of the jar files:
Set your CLASSPATH as you would to start the JDBC Server. 1.
Issue the following command:
java.com.tandem.jdbc.server.T0327Server -version
If the wrong jdbcServer.jar file is in your CLASSPATH or in the ext directory, this application displays an error
message.
2.
Set your CLASSPATH as you would to start a client application. 3.
Issue the following command:
java.com.tandem.jdbc.server.T0327Server -client
If the wrong t3client.jar file is in your CLASSPATH or in the ext directory, this application displays an error
message.
4.
Extracting the JDBC Server Archive for Applet Access
The Java Virtual Machines (JVMs) included with some web browsers do not correctly interpret JAR files. If you plan to use
the NonStop JDBC Server from a Java applet, Compaq recommends that you do the following:
Extract jdbcServer.jar into the applet's CODEBASE directory so the applet can access the JDBC Server files
individually. (An applet's CODEBASE directory, specified in the HTML file that calls the applet, tells the web browser
the absolute or relative path to the class files that the applet uses.)
●
Leave a copy of jdbcServer.jar in its installed location so other Java programs can continue to access it. For
example, if you have an applet named adverbsApplet whose CODEBASE directory is set to
/users/lolly/adverbsApplet, you can extract the JDBC Server archive into this directory as follows:
cd /users/lolly/adverbsApplet
jar xf jdbcServer.jar
●
Starting the JDBC Server
The JDBC Server is the RMI server component of the NonStop JDBC server. It passes JDBC calls from the Type 3 JDBC
driver on the client to the appropriate type 2 JDBC driver on the server. The JDBC driver on the client communicates with the
RMI registry on the Compaq server to locate the JDBC server program. Before a client program can use the NonStop JDBC
Server, both an RMI registry and the JDBC Server must be running. Optionally, you can specify an option that tells the JDBC
Server to start a registry on the port specified when you start the server.
The JDBC server runs with a security manager. As with any other application running with a security manager, the JDBC
server must have the appropriate permission to access system resources, in particular to access the network through the use of
sockets. Permissions are granted to code based on the policy in effect. By default, the policy is specified in a policy