persistence

I am using JPA 2. For safety reasons, I am working type safe with CriteriaQuery's (and thus, I am not searching for any solutions to typed queries and so on). I recently came across an issue in which I needed to set a SQL-LIMIT. After a lot of searching, I was still not successful in finding a solution. CriteriaQuery<Product> query = getEntityManager().getCriteriaBuilder().createQuery(Product.class); Root<Product> product = query.from(Product.class); query.select(product); return em.createQuery(query).getResultList(); Can anyone help me? Francisco Spaeth Define limit and offset on the Query :

I'm making a game and when I close the app (close at multitask manager), all my data is gone! So, My question is very simple: How do I save the data? Rok Jarc Let's say you want to save score and level, which are both properties of an object called dataHolder. DataHolder can be created as a singleton, so you don't have to worry too much about from where you access it (its sharedInstance actually): It's code would look a bit like this: DataHolder.h #import <Foundation/Foundation.h> @interface DataHolder : NSObject + (DataHolder *)sharedInstance; @property (assign) int level; @property (assign)

What and when is the best scenario to use DiscriminatorValue annotation in hibernate? These 2 links help me understand the inheritance concept the most: http://docs.oracle.com/javaee/6/tutorial/doc/bnbqn.html http://www.javaworld.com/javaworld/jw-01-2008/jw-01-jpa1.html?page=6 To understand discriminator, first you must understand the inheritance strategies: SINGLE_TABLE, JOINED, TABLE_PER_CLASS. Discriminator is commonly used in SINGLE_TABLE inheritance because you need a column to identify the type of the record. Example: You have a class Student and 2 sub-classes: GoodStudent and BadStudent

The users of my web application may have more than one browser window open and pointed to the same page. I would like the state of certain things in the page (loaded via ajax) to be retained across postbacks. I can either store in a cookie or on my server. Either way, I can't think of how I can distinguish each window. For example, say user Bob has two browser windows open to the ListOfSomething page. Each list has a LoadedPageNumber attribute which I need to persist. Otherwise users always end up on page 1 when they refresh. Bob might have loaded browser window 1 and pointed it to page 5 and

I am currently using memcached with my java app, and overall it's working great. The features of memcached that are most important to me are: it's fast, since reads and writes are in-memory and don't touch the disk it's just a key/value store (since that's all my app needs) it's distributed it uses memory efficiently by having each object live on exactly one server it doesn't assume that the objects are from a database (since my objects are not database objects) However, there is one thing that I'd like to do that memcached can't do. I want to periodically (perhaps once per day) save the cache