APEX fails with Java stored procedure that creates a JDBC connection

Question

Hello!
We are facing a strange problem since we have upgraded from Oracle 10g and Apache to Oracle 11g with Embedded Gateway.
Here is what we do:
** APEXX calls a PL/SQL package function "OPEN_CONNECTION" that wraps a Java stored procedure called "openConnection".*
FILE_READER_REMOTE_API.openConnection(user, password, host, port, service);
** The Java stored procedures "openConnection" opens a JDBC connection to an other database:*
public class FileReaderRemote {
private static Connection conn = null;
private static DefaultContext remoteContext = null;
public static void openConnection(String user, String password, String host, String port, String service) throws SQLException {
// Load the Oracle JDBC driver
DriverManager.registerDriver(new oracle.jdbc.OracleDriver());
java.util.Properties props = new java.util.Properties();
props.put ("user", user);
props.put ("password", password);
//props.put ("database", "//" + host + ":" + port + "/" + service);
props.put ("database", host + ":" + port + ":" + service);
props.put("v$session.program", "FileReaderRemote2");
// Connect to the database
remoteContext = Oracle.getConnection("jdbc:oracle:thin:", props);
This procedure used to work fine before the upgrade, but now we see the following:
* It still works when called directly from TOAD or SQL*Plus, even under the user ANONYMOUS.
* When called from APEX and the target database is Oracle 11g, it still works.
* When called from APEX and the target database is Oracle 10g, it takes several minutes and we receive this error:
*"Socket read timed out"*
We have tested the following workaround:
We have created a database link to our own database and called the stored procedure through that database link.
FILE_READER_REMOTE_API.openConnection*@loopback*(user, password, host, port, service);
This works, but is not really an option.
I hope some one of you can explain this strange behaviour to me.
Best regards,
Matthias

Answer 1

You wrote
"Java stored procedures -- by definition - are stored in the 8i rdbms. !!"
From the Oracle8i Java Stored Procedures Developer's Guide
Release 8.1.5
A64686-01
"If you create Java class files on the client side, you can use loadjava to upload them into the RDBMS. Alternatively, you can upload Java source files and let the Aurora JVM compile them. In most cases, it is best to compile and debug programs on the client side, then upload the class files for final testing within the RDBMS"
This means that you can create shared classes that are used on both the client and server side. The source does not need to reside within the server (according to their documentation). Please also note the following from the Oracle8i JDBC Developer's Guide and Reference Release 8.1.5 A64685-01 for using the getConnection() method on the server:
"If you connect to the database with the DriverManager.getConnection() method, then use the connect string jdbc:oracle:kprb:. For example:
DriverManager.getConnection("jdbc:oracle:kprb:");
Note that you could include a user name and password in the string, but because you are connecting from the server, they would be ignored."
So if you're coding a shared class that is to run on both the client and server side, you might do something like this:
Connection conn =
DriverManager.getConnection(
System.getProperty("oracle.server.version") == null
? "jdbc:oracle:thin:@hostname:1521:ORCL"
: "jdbc:oracle:kprb:"),
"youruserid","yourpassword");
As stated earlier, the userid and password are supposedly ignored for server connections retrieved in this manner. I haven't tried this yet, but it is documented by Oracle.
Regards,
Steve
null