How to upload a file to the process from a service task?

[rgonzalez]

Hi everyone,

I'm using APS v1.6.1 and I need to create an spreadsheet document and upload it to the process and then show it in a user task.

I 've managed to create a service task, implementing a JavaDelegate, and use the aspose API to create the file on disk, but I`m stuck on how to upload this file to the process, to showing it in the next usertask. I haven't found information on this topic, so I need some help on how to do it or which classes to use.

Thanks!

[gdharley]

Not sure what you mean by "upload".

Are you talking about uploading from a user browser?

Or are you talking about creating the file in a filesystem available to the process server?

Or are you talking about sending the file to an ECM system?

If you have created a file using a javaDelegate then I assume the file resides on the process sever somewhere.

If that's the case, why would you want to upload it. You would be better served putting it somewhere that can be retrieved via a rest call and simply tracking the URL for the file.

Then when you need to display it, you can reference the URL to open a window, download or preview the document.

If you are using 1.6.1, then the contentService bean is what you need to use, unfortunately it is not documented so you get to crawl the source.

Greg

‌

[rgonzalez]

Hi Greg,

With "upload", I refer to attach the file on a field in the process, now I generate the file directly on the server file system, and I don´t know how to relate this file with a field in the process than can be shown afterwards in a usertask.

I`m starting to use APS v1.6.1, and I don´t have much knowledge about the activiti java API. I will try to explore contentService bean.

[rgonzalez]

I've been investigating how the ootb GenerateDocumentTask works, and I've prepare the following code, but always get the following error on the function "relatedContentService.createRelatedContent".

01:57:10,566 [http-nio-8080-exec-3] ERROR org.activiti.engine.impl.interceptor.CommandContext  - Error while closing command context
java.lang.NullPointerException
        at com.activiti.extension.bean.CreatingWorkbook.execute(CreatingWorkbook.java:94)
        at org.activiti.engine.impl.delegate.JavaDelegateInvocation.invoke(JavaDelegateInvocation.java:34)
        at org.activiti.engine.impl.delegate.DelegateInvocation.proceed(DelegateInvocation.java:37)
        at org.activiti.engine.impl.delegate.DefaultDelegateInterceptor.handleInvocation(DefaultDelegateInterceptor.java:25)
        at org.activiti.engine.impl.bpmn.behavior.ServiceTaskJavaDelegateActivityBehavior.execute(ServiceTaskJavaDelegateActivityBehavior.java:49)
        at org.activiti.engine.impl.bpmn.behavior.ServiceTaskJavaDelegateActivityBehavior.execute(ServiceTaskJavaDelegateActivityBehavior.java:40)
        at org.activiti.engine.impl.bpmn.helper.ClassDelegate.execute(ClassDelegate.java:158)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:60)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:669)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:664)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerStart.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerStart.java:52)
        at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:669)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:664)
        at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:49)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:669)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:664)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionCreateScope.execute(AtomicOperationTransitionCreateScope.java:49)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:669)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:664)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerTake.execute(AtomicOperationTransitionNotifyListenerTake.java:80)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:669)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:664)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionDestroyScope.execute(AtomicOperationTransitionDestroyScope.java:116)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:669)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:664)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationTransitionNotifyListenerEnd.eventNotificationsCompleted(AtomicOperationTransitionNotifyListenerEnd.java:35)
        at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:669)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:664)
        at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:49)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:669)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:664)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.take(ExecutionEntity.java:481)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.take(ExecutionEntity.java:459)
        at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performOutgoingBehavior(BpmnActivityBehavior.java:140)
        at org.activiti.engine.impl.bpmn.behavior.BpmnActivityBehavior.performDefaultOutgoingBehavior(BpmnActivityBehavior.java:66)
        at org.activiti.engine.impl.bpmn.behavior.FlowNodeActivityBehavior.leave(FlowNodeActivityBehavior.java:44)
        at org.activiti.engine.impl.bpmn.behavior.FlowNodeActivityBehavior.execute(FlowNodeActivityBehavior.java:36)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationActivityExecute.execute(AtomicOperationActivityExecute.java:60)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:669)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:664)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationProcessStartInitial.eventNotificationsCompleted(AtomicOperationProcessStartInitial.java:45)
        at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:669)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:664)
        at org.activiti.engine.impl.pvm.runtime.AtomicOperationProcessStart.eventNotificationsCompleted(AtomicOperationProcessStart.java:64)
        at org.activiti.engine.impl.pvm.runtime.AbstractEventAtomicOperation.execute(AbstractEventAtomicOperation.java:56)
        at org.activiti.engine.impl.interceptor.CommandContext.performOperation(CommandContext.java:97)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperationSync(ExecutionEntity.java:669)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.performOperation(ExecutionEntity.java:664)
        at org.activiti.engine.impl.persistence.entity.ExecutionEntity.start(ExecutionEntity.java:409)
        at org.activiti.engine.impl.cmd.StartProcessInstanceCmd.execute(StartProcessInstanceCmd.java:110)
        at org.activiti.engine.impl.cmd.StartProcessInstanceCmd.execute(StartProcessInstanceCmd.java:37)
        at org.activiti.engine.impl.interceptor.CommandInvoker.execute(CommandInvoker.java:24)
        at org.activiti.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:57)
        at org.activiti.spring.SpringTransactionInterceptor$1.doInTransaction(SpringTransactionInterceptor.java:47)
        at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:133)
        at org.activiti.spring.SpringTransactionInterceptor.execute(SpringTransactionInterceptor.java:45)
        at org.activiti.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:31)
        at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:40)
        at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:35)
        at org.activiti.engine.impl.RuntimeServiceImpl.startProcessInstance(RuntimeServiceImpl.java:466)
        at org.activiti.engine.impl.runtime.ProcessInstanceBuilderImpl.start(ProcessInstanceBuilderImpl.java:76)
        at com.activiti.service.runtime.ActivitiService.startProcessInstance(ActivitiService.java:51)
        at com.activiti.service.runtime.ActivitiService$$FastClassBySpringCGLIB$$87164725.invoke(<generated>)
        at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:717)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
        at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
        at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
        at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
        at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:653)
        at com.activiti.service.runtime.ActivitiService$$EnhancerBySpringCGLIB$$d8174b05.startProcessInstance(<generated>)
        at com.activiti.service.runtime.ProcessInstanceService.startNewProcessInstance(ProcessInstanceService.java:79)
        at com.activiti.service.runtime.ProcessInstanceService$$FastClassBySpringCGLIB$$82da82a2.invoke(<generated>)
        at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:717)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
        at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
        at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
        at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
        at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:653)
        at com.activiti.service.runtime.ProcessInstanceService$$EnhancerBySpringCGLIB$$af28dbe2.startNewProcessInstance(<generated>)
        at com.activiti.service.runtime.AlfrescoProcessInstanceService.startNewProcessInstance(AlfrescoProcessInstanceService.java:338)
        at com.activiti.rest.runtime.ProcessInstancesResource.startNewProcessInstance(ProcessInstancesResource.java:31)
        at com.activiti.rest.runtime.ProcessInstancesResource$$FastClassBySpringCGLIB$$c5b1caab.invoke(<generated>)
        at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
        at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:717)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
        at com.ryantenney.metrics.spring.TimedMethodInterceptor.invoke(TimedMethodInterceptor.java:48)
        at com.ryantenney.metrics.spring.TimedMethodInterceptor.invoke(TimedMethodInterceptor.java:34)
        at com.ryantenney.metrics.spring.AbstractMetricMethodInterceptor.invoke(AbstractMetricMethodInterceptor.java:59)
        at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
        at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:653)
        at com.activiti.rest.runtime.ProcessInstancesResource$$EnhancerBySpringCGLIB$$59740f84.startNewProcessInstance(<generated>)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
        at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:137)
        at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:110)
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:776)
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:705)
        at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959)
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:893)
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
        at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:868)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
        at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
        at com.codahale.metrics.servlet.AbstractInstrumentedFilter.doFilter(AbstractInstrumentedFilter.java:97)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
        at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:316)
        at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:126)
        at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:90)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
        at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:114)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
        at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:122)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
        at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
        at org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter.doFilter(RememberMeAuthenticationFilter.java:149)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
        at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:168)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
        at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:48)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
        at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:205)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
        at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:120)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
        at com.activiti.security.CustomStatelessCSRFFilter.doFilterInternal(CustomStatelessCSRFFilter.java:68)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
        at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:64)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
        at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:91)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
        at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:53)
        at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
        at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
        at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:213)
        at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:176)
        at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:344)
        at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:261)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
        at org.apache.catalina.filters.CorsFilter.handleNonCORS(CorsFilter.java:436)
        at org.apache.catalina.filters.CorsFilter.doFilter(CorsFilter.java:177)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
        at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
        at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1099)
        at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:670)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.lang.Thread.run(Unknown Source)

The code:

package com.activiti.extension.bean;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import org.activiti.engine.delegate.DelegateExecution;
import org.activiti.engine.delegate.DelegateHelper;
import org.activiti.engine.delegate.Expression;
import org.activiti.engine.delegate.JavaDelegate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.transaction.support.TransactionSynchronizationAdapter;
import org.springframework.transaction.support.TransactionSynchronizationManager;

import com.activiti.api.docgen.TemplateVariableProcessor;
import com.activiti.api.docgen.TemplateVariableProducer;
import com.activiti.domain.runtime.RelatedContent;
import com.activiti.domain.runtime.RuntimeDocumentTemplate;
import com.activiti.security.SecurityUtils;
import com.activiti.service.runtime.ContentRenditionService;
import com.activiti.service.runtime.RelatedContentService;
import com.activiti.service.runtime.RuntimeDocumentTemplateService;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.aspose.cells.*;

public class CreatingWorkbook implements JavaDelegate {
    private static Logger logger = LoggerFactory.getLogger(CreatingWorkbook.class);
    @Autowired
    protected RelatedContentService relatedContentService;
    
    @Autowired
    protected ContentRenditionService contentRenditionService;

    private Expression VariableName;

        public void setVariableName(Expression VariableName) {
            this.VariableName = VariableName;
        }

    @Override
    public void execute(DelegateExecution execution) throws Exception {
        String variableName = (String) VariableName.getValue(execution);

        // Instantiating a Workbook object that represents a Microsoft Excel file.
        Workbook wb = new Workbook();

        // Note when you create a new workbook, a default worksheet, "Sheet1", is by default added to the workbook. Accessing the
        // first worksheet in the book ("Sheet1").
        Worksheet sheet = wb.getWorksheets().get(0);

        // Access cell "A1" in the sheet.
        Cell cell = sheet.getCells().get("A1");

        // Input the "Hello World!" text into the "A1" cell
        cell.setValue("Hello World!");

        // Adding a new worksheet to the Workbook object
        WorksheetCollection worksheets = wb.getWorksheets();

        int sheetIndex = worksheets.add();
        sheet = wb.getWorksheets().get(sheetIndex);

        // Setting the name of the newly added worksheet
        sheet.setName("My Worksheet");
        
        // Setting the newly added worksheet as active
        wb.getWorksheets().setActiveSheetIndex(sheetIndex);

        // Save the Microsoft Excel file.
         File tempFile = File.createTempFile("activiti-generated-document", ".xlsx");
        FileOutputStream outputStream = new FileOutputStream(tempFile);
        wb.save(outputStream, SaveFormat.XLSX);
        outputStream.flush();
        outputStream.close();


        // Store related content
            //RelatedContent relatedContent = null;
        
            //relatedContent = storeAsRelatedContent(execution, "workbook.xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", variableName, new FileInputStream(tempFile));
               
        InputStream inputStream = new FileInputStream(tempFile);

        logger.info("getCurrentUserObject = " + SecurityUtils.getCurrentUserObject());
        logger.info("getProcessInstanceId = " + execution.getProcessInstanceId());
        logger.info("variableName = " + variableName);

        final RelatedContent relatedContent = relatedContentService.createRelatedContent(SecurityUtils.getCurrentUserObject(), "workbook.xlsx", null, null, null, execution.getProcessInstanceId(),
            variableName, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", inputStream, null);

        if (inputStream != null) {
            try {
                inputStream.close();
            } catch (IOException e) { }
        }

        TransactionSynchronizationManager.registerSynchronization(new TransactionSynchronizationAdapter() {
            @Override
            public void afterCommit() {
                contentRenditionService.asyncProcessContentAndQueueRendition(relatedContent.getId());
            }
        });

        logger.info("relatedContent = " + relatedContent.getId());

            // Store execution variable
            if (relatedContent != null) {
                execution.setVariable(variableName, relatedContent.getId());
            }
        
            // delete temp file
            tempFile.delete();
    }
}

[abdeljali_hmi]

Hello if that works for you give me the method (code) !