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

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 (f.e. 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);
        }
    }
}