Question

my case is : a save method in ResourceService<T , ID >

public interface IResourceService<T,ID>

public class ResourceService<T , ID> implement IResourceService<T,ID>
{
   public void save(T entity) throws RuntimeException {

    try {
        AsyncServiceSaveRunable<T> task = new
AsyncServiceSaveRunable<T>(getService(),entity);

        this.treadPoolExcutor.submitTask(task);
    } catch (NoSuchMethodException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }


   }
}

and in

public class AsyncServiceSaveRunable<T> implements Runnable  {
private IResourceService<?,?> service; //----> this is 
private Method serviceMethod;
private List<T> parameters;

public AsyncServiceSaveRunable(IResourceService<?,?> service,  List<T> parameters){ 
}

public AsyncServiceSaveRunable(IResourceService<?,?> service, T parameter)
                            throws NoSuchMethodException, SecurityException{

    this.service         = service;

    this.parameters = new ArrayList<T>();
    this.parameters.add(parameter);
}
@Override
public void run() {
    try {
        if(this.parameters.size()>1)
            service.saveList(this.parameters);
        else
            service.save( this.parameters.get(0));
    } catch (IllegalAccessException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IllegalArgumentException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (InvocationTargetException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

  }
 }

the problem is service.saveList(this.parameters); and service.save(…);
are wrong

is there anyway to pass that parameter
or i need a different of structure to deal this kind of case?

Thanks

——————error message from eclipse ————————

The method save(capture#7-of ?) in the type IResourceService<capture#7-of ?,capture#8-of ?>
 is not applicable for the arguments (T)

Answer 1

In ResourceService<T extends BaseEntity, ...> you require T to be drevied from BaseEntity.

In public class AsyncServiceSaveRunable<T> T has no restrictions.

Then in service.save(this.parameters.get(0)); you try to pass the (unbounded) generics type to a function that requires a BaseEntity object (or one derived from it).

You can require the type parameter of AsyncServiceSaveRunable to be derived from BaseEntity as well:

public class AsyncServiceSaveRunable<T extends BaseEntity>

UPDATE:
The error message is that the first type parameter of IResourceService is not valid for the type required by save(). Previously you had the type parameter bounded by BaseEntry, but this restriction is now missing. Maybe you want to write: IResourceService<? extends BaseEntity, ? extends Serializable>?