Regenerate thumbnails using synthetic workflow

regenerate thumbnails.jsp

<%@include file="/libs/foundation/global.jsp"%>
<%@page session="false" contentType="text/html; charset=utf-8" pageEncoding="UTF-8"
    import="com.adobe.acs.commons.workflow.synthetic.*, 
    com.adobe.acs.commons.fam.*,
    com.adobe.acs.commons.functions.*,
    org.apache.sling.api.resource.*,
    java.util.*,
    javax.jcr.*,
    com.day.cq.search.*,
    com.day.cq.dam.commons.util.DamUtil,
    com.day.cq.wcm.api.*,
    com.day.cq.dam.api.*"%><%

    BiFunction<ResourceResolver, String, Boolean> oldRenditions = 
    new BiFunction<ResourceResolver, String, Boolean>() {
        @Override
        public Boolean apply(ResourceResolver r, String path) {
            Resource res = r.getResource(path);
            Asset asset = DamUtil.resolveToAsset(res);
            if (asset == null) {
                return false;
            }
            Rendition original = asset.getRendition("original");
            if (original == null) {
                return false;
            }
            long originalTime = original.getResourceMetadata().getCreationTime();
            int counter = 0;
            for (Rendition rendition : asset.getRenditions()) {
                counter++;
                long time = rendition.getResourceMetadata().getCreationTime();
                if (time < originalTime) {
                    return true;
                }                        
            }
            return counter <= 1;
        }
    };   

    SyntheticWorkflowRunner swr = sling.getService(SyntheticWorkflowRunner.class);
    ActionManagerFactory amf = sling.getService(ActionManagerFactory.class);
    DeferredActions actions = sling.getService(DeferredActions.class);
    SyntheticWorkflowModel model = swr.getSyntheticWorkflowModel(
        resourceResolver, "/etc/workflow/models/my-thumbnail-workflow-model", true
    );
   ActionManager manager = amf.createTaskManager("Fiddle", resourceResolver, 10);
   int numberOfAssets = manager.withQueryResults(
        "SELECT * FROM [dam:Asset] as a WHERE ISDESCENDANTNODE(a,'/content/dam')",
        "JCR-SQL2",
        actions.startSyntheticWorkflows(model),
        oldRenditions
    );
   manager.addCleanupTask();
%>
Finished adding <%=numberOfAssets%> items.