Soot not finding class without a main for call graph

Question

Good day,

I am new to Soot and have been trying to get Soot working on analyzing the call graph of external libraries/apps. Specifically, I want to get the call graph of a class, ‘DefaultServlet’, within a Tomcat jar file, ‘catalina.jar’. First, I followed tutorials (e.g. O2Lab) that analyze a simple class/file with a main method. However, the classes I want to analyze don’t typically have main methods. So I found and followed examples (e.g. Heros) that utilize entrypoints but Soot is still unable to find the class. Please, I would appreciate some help. Here is the latest main piece of code I have tried.

public class IFDSDataFlowTransformer extends SceneTransformer {
    
    static LinkedList<String> excludeList;
    static String mainclass = "DefaultServlet";
    static String mainmethod = "doGet"; // "doPut";

    public static void main(String[] args)  {
        
        // Set Soot's internal classpath
        String javapath = System.getProperty("java.class.path");
        String jredir = System.getProperty("java.home")+"/lib/rt.jar";
        String path = javapath+File.pathSeparator+jredir;
        Options.v().set_soot_classpath(path);

        // Enable whole-program mode
        Options.v().set_whole_program(true);
        Options.v().set_app(true);

        // Call-graph options
        Options.v().setPhaseOption("cg", "safe-newinstance:true");
        Options.v().setPhaseOption("cg.cha","enabled:false");

        // Enable SPARK call-graph construction
        Options.v().setPhaseOption("cg.spark","enabled:true");
        Options.v().setPhaseOption("cg.spark","verbose:true");
        Options.v().setPhaseOption("cg.spark","on-fly-cg:true");

        Options.v().set_allow_phantom_refs(true);

        // Set the main class of the application to be analysed
        Options.v().set_main_class(mainclass);

        // Load the main class
        SootClass c = Scene.v().loadClass(mainclass, SootClass.BODIES);
        c.setApplicationClass();

        // Load the "main" method of the main class and set it as a Soot entry point
//        SootMethod entryPoint = c.getMethodByName("main");
        SootMethod entryPoint = c.getMethodByName(mainmethod);
        List<SootMethod> entryPoints = new ArrayList<SootMethod>();
        entryPoints.add(entryPoint);
        Scene.v().setEntryPoints(entryPoints);
        
        PackManager.v().getPack("wjtp").add(new Transform("wjtp.herosifds", new IFDSDataFlowTransformer()));
        
//        soot.Main.main();
        //start working
        PackManager.v().runPacks();
    }

I am using Soot 3.3.1, Java 1.8 and I have a photo of my Eclipse project structure below. The files, IFDSDataFlowTransformer and TestSootCallGraph, start two separate trials. Do I have to create a new class with a main that would start a request (e.g. http or curl request) to the Tomcat application? If so, that would require including more Tomcat jars/files in the project. However, I figured that Soot did not need specific inputs or all files in an application to statically analyze code.

Thank you

Eclipse structure