How to call a java shared script library from a Java agent in Xpages?

Question

I have an agent that is set to run every day at 8:00
I want to write a java code (in a shared library) and call that library from the agent with parameters.

For Example:

Agent code:

    // ....
    checkAndSendMail(email_1);
    checkAndSendMail(email_2);
    // ....

java library code:

public class Check{       
    public void checkAndSendMail(String email_param){
        // ...
        mail.send(email_param);
        // ...
    }    
}

• Can I call a java shared script library from a Java agent in Xpages?
• if yes, then how to call?

Answer 1

The JVM in XPages and Domino Java Agents is separate so you can't share java code between them. You can create java code if you go to script libraries section in the designer

not the Java/Jar section that is for XPages. And create a new Java Library that can be included inside a Java agent.

Answer 2

You can do this, but this is only possible with a lot of "overhead". Assuming you want to load a Java class in an Agent you could do the following:

1. Get the design note containing your class (fe with a special design view or the Java NAPI)
2. Export the note with DXL
3. Extract the content all "$ClassData" fields
4. Base64 decode the content
5. Skip the first 42 bytes , and load the resulting byte array with your own class loader (override the findClass method which does a defineClass call)
6. Now you can instantiate the class in your agent and access it via reflection

As you can see, it is possible, but for a higher effort than just "doubling" the libraries in the DDE.

EDIT:

Here is an example class loader for an agent. The Base64 encoded DXL is already added. The agent instantiates the class ch.hasselba.demo.LoadedClass and calls the method printTime() :

package ch.hasselba.demo;

public class LoadedClass {

    public void printTime(){
        System.out.println("Time: " + System.currentTimeMillis() );
    }
}

The code of the agent (uses lwpd.commons.jar )

import lotus.domino.AgentBase;
import com.ibm.commons.util.io.base64.Base64;
import java.lang.reflect.Method;

public class JavaAgent extends AgentBase {

    public void NotesMain() {

        try {
            // trucated DXL string
            String dataDXL = "YQAYAAAAAACqAgAAAQAAAAAAAAAAAAAAYAC8AgAAqgKqAgAAAAAAAAAAyv66vgAAADEALwcAAgEAFWNoL2hhc3NlbGJhL3hwYWdlcy9aWgcA";

            // base64 decode the string
            String b64 = Base64.decode(dataDXL);
            byte[] b64Bytes = b64.getBytes();
            byte[] classBytes = new byte[b64Bytes.length - 42];

            // skip the first 42 bytes
            System.arraycopy( b64Bytes, 42, classBytes, 0, b64Bytes.length - 42);

            try {
                // load the class
                ByteClassLoader obj = new ByteClassLoader();
                Class theClass = obj.findClass("ch.hasselba.demo.LoadedClass", classBytes);
                // instantiate it
                Object theInstance = theClass.newInstance();

                // get the method printTime via Reflection & call it
                Method theMethod = theInstance.getClass().getMethod("printTime", null);
                theMethod.invoke( theInstance, null);
            } catch (Exception e) {
                e.printStackTrace();
            }

        } catch (Exception e) {
            e.printStackTrace();

        }
    }

    // the class loader
    public static class ByteClassLoader extends ClassLoader {

        public Class findClass(String name, byte[] data) {
            return defineClass(name, data, 0, data.length);
        }
    }
}

Answer 3

Mike, Fredrik is right - no sharing. Unless... you package your shared code into a Jar and deploy that one to the jvm/lib/ext directory of your server and/or client. Your admin will not like that potentially. There was a patched version of the updatesite.ntf on OpenNTF that allowed to deploy plug-ins into the server OS. You could hack the script to deploy a jar into the ext directory. But please only with admin's consent.

:-) stw