RequestFactory findXXX method cause performance pitfall

[Lopakhin]

In a common scenario of Web application, we usually populate cellTable,cellList with our data from RequestFactory context's method, such as findAll(), at this point , we already done  the database query that get all entity ,but RequestFactory dictate that , to prepare with appropriate manipulating methods , RF has to go over the list again one by one ,resulting in additional n queries whose result set already in the memory.As I monitored in the console, the overhead is substantial, even with JPA batching present, the performance is still crippled.

According to this post in stackoverflow , we surely can override ServiceDecorator,but it seems that we lose the control over what we can do with this entity.

By far I can not think better solution for this, may be go back to GWT RPC is good idea.

[Thomas Broyer]

You can use a Locator and override its isLive() method (whose default implementation calls getId() and then find())

(IMO, you *should* use a Locator rather than this static-methods anti-pattern anyway)

[Jesse Hutton]

Another way to mitigate this problem is to always use
EntityManager#find() in your Locator since that will return the entity
from the current persistence context without hitting the db if it is
already there.

Jesse

[Lopakhin]

Both solutions are great, and I re-read RF official documentation ,it actually uses Jesse's solution which I did't get it in the first place.