Auto-Assign Issue using custom field

package com.newisys.jira.workflow.function;

import com.opensymphony.module.propertyset.PropertySet;
import com.opensymphony.workflow.FunctionProvider;

import org.apache.log4j.Category;
import org.ofbiz.core.entity.GenericValue;

import java.util.Iterator;
import java.util.List;
import java.util.Map;

import com.atlassian.jira.util.JiraUtils;
import com.atlassian.jira.issue.CustomFieldManager;
import com.atlassian.jira.issue.fields.CustomField;

/**
 *  Assign issue using value in custom field
 *
 *  Required Argument: name - contains the name of the custom field that contains value
 *
 *  Note: No validation on custom field contents is preformed
 */
public class AssignIssueFromCustomField implements FunctionProvider
{
    private static final Category log = Category.getInstance(AssignIssueFromCustomField.class);

    public void execute(Map transientVars, Map args, PropertySet ps)
    {
        // Get the name of the link type
        String customFieldName = (String) args.get("name");
        if (customFieldName == null) throw new IllegalArgumentException("Must specify a 'name' arg specifying name of the custom field");

        try
        {
            // get compoent from custom field
            GenericValue issue = (GenericValue) transientVars.get("issue");

            // get issue custom fields
            List customFields = ManagerFactory.getCustomFieldManager().getCustomFieldObjects()

            // This line doesn't work yet... :(
            //((CustomFieldManager)JiraUtils.loadComponent(CustomFieldManager.class)).getCustomFieldObjects(issue);

            // get custom field
            CustomField cf = null;
            Iterator cfit = customFields.iterator();
            while(cfit.hasNext())
            {
                cf = (CustomField ) cfit.next();
                if(cf.getName().equals(customFieldName))
                {
                    // ok, we have the custom field object now - get the value and set the issue assignee property
                    String customFieldValue = (String ) cf.getValue(issue);

                    //log.error("customFieldValue: " + customFieldValue);
                    issue.set("assignee", customFieldValue);

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