java assign map each value into an String array

Question

I want to save data into master - details table.First portion is for master table and last portion is for details table.I have got java.lang.String cannot be cast to [Ljava.lang.String .How to recover from this problem.How to assign map.get("step_id[]") into a string array String[] WfIds. I want to assign each value into distinct string array.

Controller Code

 Map<String,Object> wfManager = new HashMap<String,Object>();

//************************Master data sent from view******************************//

   wfManager.put("workflow_code",(request.getParameter("workflow_code")).toUpperCase());
   wfManager.put("workflow_name",request.getParameter("workflow_name"));
   wfManager.put("workflow_descr",request.getParameter("workflow_descr"));
   wfManager.put("object_type_code",request.getParameter("object_type_code"));

//*********************Detail item data sent from view********************************//

    wfManager.put("wf_block_id[]",              request.getParameter("wf_block_id[]"));
    wfManager.put("step_code[]" ,               request.getParameter("step_code[]"));
    wfManager.put("step_name[]",                request.getParameter("step_name[]"));
    wfManager.put("doa_type_code[]",            request.getParameter("doa_type_code[]"));
    wfManager.put("doa_type_name[]",            request.getParameter("doa_type_name[]"));

Service Code

public Map<String, String> insert(Map<String, Object> map) {

//************************Master data sent from view******************************//

Map<String, String> data = new HashMap<String, String>();
    Workflow wf = new Workflow();

    wf.setWorkflowCode((String)map.get("workflow_code"));
    wf.setWorkflowName((String)map.get("workflow_name"));
    wf.setWorkflowDescr((String)map.get("workflow_descr"));
    wf.setObjectTypeCode((String)map.get("object_type_code"));

        String[] WfIds                  = (String[]) map.get("step_id[]");
        String[] wfBlockIds             = (String[]) map.get("wf_block_id[]");
        String[] wfsCodes               = (String[]) map.get("step_code[]");
        String[] stepNames              = (String[]) map.get("step_name[]");
        String[] doaTypeCodes           = (String[]) map.get("doa_type_code[]");
        String[] doaTypeNames           = (String[]) map.get("doa_type_name[]");


List<WorkflowDetails> wfDetailsList = new ArrayList<WorkflowDetails>();


for(int i = 0; i< wfsCodes.length; i++){
            WorkflowDetails wfDetails = new WorkflowDetails();

        wfDetails.setWorkflowCode(wf.getWorkflowCode());
        wfDetails.setWorkflowName(wf.getWorkflowName());
        wfDetails.setWorkflowDescr(wf.getWorkflowDescr());
        wfDetails.setWorkflowObjectTypeCode(wf.getObjectTypeCode());
        wfDetails.setWorkflowObjectTypeName(wf.getObjectTypeName());
       wfDetailsList.add(i,wfDetails);  
        }

        wf.setSteps(wfDetailsList);

        id = workflowManagerDAO.insertDoc(wf);
         data.put("id", id);


  return data;

} Code for DAO:

    @Transactional
@Override
public String insertDoc(Workflow wfManager) {
    for(int i = 0; i < wfManager.getSteps().size(); i++){
        WorkflowDetails wfDetails = new WorkflowDetails();
        wfDetails = wfManager.getSteps().get(i);
        sessionfactory.getCurrentSession().save(wfDetails);
        sessionfactory.getCurrentSession().flush();
    }
    String id = (String) sessionfactory.getCurrentSession().save(wfManager);
    sessionfactory.getCurrentSession().flush();
    return id;
}

`map.get("step_id[]");` is probably not a `String[]` (or anything else in its type heirarchy). Thus, you cannot cast to it from there. Refer to http://stackoverflow.com/questions/5289393/casting-variables-in-java — ifly6, Jul 26 '16 at 07:43
In my problem step_id[] is a String[] and it is now value of a map.I want to get it and assign it into a String[] stepIds. — M.Topa, Jul 26 '16 at 07:47
Give me the full error code. Because `java.lang.String cannot be cast to [Ljava.lang.String` is impossible. — ifly6, Jul 26 '16 at 07:48
Oh, I misinterpreted. However it is, you cannot cast a `String` to a `String[]`, which is your problem. One of the datatypes is a `String` and you cannot simply treat it as if it were a `String[]`. — ifly6, Jul 26 '16 at 07:56

score 0 · Answer 1 · edited May 23 '17 at 12:08

If you absolutely need to use request.getParameter(), you will have to convert your arrays to strings using a delimiter character, e.g. convert this

String[] array = { "John", "Peter", "Paul" };

to this

String plainTextArray = "John#Peter#Paul";

Then you will be able to pass you array values as String (the only type that getParameter() understands).
You can then restore them like this

String[] restoredArray = request.getParameter("plainTextArray").split("#");

Maybe you want to have a look at setAttribute() and getAttribute() which let you store any objects (including arrays). You can start here Difference between getAttribute() and getParameter()

java assign map each value into an String array

1 Answers1