persistence

I'm looking for something like the keychain on the iPhone, but for Android development. Something that gives me the possibility to save small key-value pairs, that are persistent and unchanged even if the user reinstalls the application. Is there something like that? Can I use the standard preferences that way? I would like to achieve a behavior in a way it works with games on a PC writing the save games to another folder so that after delete and later reinstall they are not lost. Edit The bounty run out without somebody mentioning the accountManager. I just stumbled over it. Wouldn't that be

I have two questions concerning @JoinFormula and @OneToMany annotations: How can I limit the number of result with @JoinFormula and @OneToMany annotations? How can I define that id in expression author = id refers to Author.id ? Author { @Id private Long id; @OneToMany @JoinFormula(value = "SELECT a FROM Article a WHERE author = id AND schedule < CURRENT_TIMESTAMP()") // limit = 15 private List<Article> pastArticles; } Like this, I keep having the pastArticles empty, even when I remove the schedule < part of the clause. Thanks! Answer 1 : @Size(max=10) private List<Comment> commentList; Answer

Static variable gotcha in php I am from Java background and have switched to php for one project recently. I have found one unexpected behaviour in php. Value set to some static variable is not staying persistent across the requests. I am not sure if this is the expected bahaviour. Because in java , you can always persist very commonly used variables or say constants like dbname,hostname,username,password across the requests so that you don't have to read them always from local property files. Is this behaviour normal ? And if it is normal then is there any alternative by which I can persist

This is from Apple docs: When you design a game that reports scores to Game Center, you should also consider the security needs of your game. You want scores reported to Game Center to be an accurate accounting of how players are doing. Here are two suggestions: Store your game’s preferences and saved games in a secure format, rather than in clear text. If your game’s data is stored in clear text, a player can download the saved game data using iTunes, modify it, and resync it back to the device. This may allow the player to achieve a higher score than you intended. Always set reasonable

I am currently using Firebase Firestore as a primary backend that retrieves data from a variety of sources. I also use Android's Room for my mobile backend. When the phone receives data it is stored in the Room database in the event the user will not go online again for days even weeks. After looking through the device files, I see firestore saves the data in files under the /data/data/<your-app>/databases directory. The file looks something like this I have read the offline persistence docs on the firestore and there is no indication on how durable the offline persistence is It mentions that

I know some software shops have been burned by using the int type for the primary key of a persistent class. That being said, not all tables grow past 2 billions. As a matter of fact, most don't. So, do you guys use the long type only for those classes that are mapped to potentially large tables OR for every persistent class just to be consistent? What's the industry concensus? I'll leave this question open for a while so that you can share with us your success/horror stories. Long can be advantageous even if the table does not grow super large, yet has a high turnover ie if rows are deleted

What are the lightweight options one has to persist Java objects ? I'm looking for the easiest possible solution. I don't want anything fancy featurewise just something simple that works with reasonnably simple objects (some collections, relationships and simple inheritance) and doesn't bring too much apparent complexity (if any) to the existing codebase. The options I'm aware of include Hibernate and frameworks such as EMF but they sound (and have been experienced to be) too complex and time-consuming. I'd like something out of the box, preferably file oriented than dababase oriented, that I