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Android - best storage method to store objects (database or json/internal storage)

I'm new to Android development. I want to do a small app that need to store quotes from famous people. I'm going to use an Object quote to store each quote. The object will be simple and only use Strings.
I want the user to be able to add quotes, but I want them to be stored so they can be saved the next time the user open the app.
I've seen a lot of questions about how to store data and they usually give you lists of available technology. I'm wondering what are the common practices among experienced developers, what are the common use for each technology.
I know it's possible to use a database. But since I only want to store a list of quotes object I'm wondering if that wouldn't be too much.
I could store it in a file in the internal storage. But then how do I store it? Should a store it in json format and every time the user start the app I simply use the json to recreate the list of quotes.
I'm not sure which way would more practical or even if using json would be effective.
Thank you for you help!

I won't recommend you to use Shared Preferences since those are intended for very short data, say 100 kb to 1 MB. In you case you can store quotes either in an sqlite database or in a file. (One that suits your need). You can test between how much time does it take to write your quote to a file and to a database, both are good choices. In both cases you should create a wrapper class and use it according to your needs, which will make the working convenient.

Saving object for future use

I am writing a program (a bot) to play a Risk-like game in an AI competition. I'm new to programming so I've used some very basic coding so far. In this game, each round the program receive some information from the game engine. In the program, I have a class BotState, which allows me to treat information from the current round, such as the opponent bot moves, or the regions currently under my control, etc. This information is put in some ArrayLists. I have some getters to access this information and use them in the main class.
My problem is that each round, the information is overwritten (each round means a new run of the program), so I can only access the information from the current round. What I would like to do is save all of the information each round, so that for example if the game state is at round 10, I still can access the moves that the opponent made on round 8.
I looked for ways to solve this problem, and I came across something named "object serialization". I didn't quite understood how it works, so I would like to know if there is a simpler/better way to do what I want, or if serialization is the way to go. Thanks for your help.
edit: I can't link the program to my disk or a database. I upload the source files of the bot to the game server, so everything has to be in the source files

Object serialization should be fairly simple for your case.
Simply put it is a way to store your object on disk and
to later on take data from the disk and recreate your object
in memory in the same state it was before serializing it.
Another way is to define some sort of representation yourself
e.g. as an XML chunk and for each object and to store those
chunks in an XML file. You can view this as a custom serialization
but it's still a serialization.
Another way is to store your objects into a database.
All in all, you need some permanent/persistent storage
for your objects (whether it's the disk directly or a DB
/which is again using the disk at the lowest level/).

Consider using a modeling framework for your application. The Eclipse Modeling Framework (EMF) comes with a simple XMI serialization built into it. If your model is small and/or simple enough it may be worth it. Have a look at this EMF introduction tutorial and this tutorial on serialization in EMF.
Also, have a look at this question: What's the easiest way to persist java objects?.

Methods of Data Storage - Opinion

I have been working on an app and have encountered some limitations relating to my lack of experience in Java IO and data persistence. Basically I need to store information on a few Spinner objects. So far I have saved information on each Spinner into a text file using the format of:
//Blank Line
Name //the first drop-down entry of the spinner
Type //an enum value
Entries //a semicolon-separated list of the drop-down entry String values
//Blank line
And then, assuming this rigid syntax is followed always, I've extracted this information from the saved .txt whenever the app is started. But things such as editing these entries and working with certain aspects of the Scanner have been an absolute nightmare. If anything is off by even one line or space of blankness BAM! everything is ruined. There must be a better way to store information for easy access, something with some search-eability, something that won't be erased the moment the app closes and that isn't completely laxed in its layout to the extent that the most minor of changes destroys everything.
Any recommendations for how to save a simple String, a simple int, and an array of String outside the app? I am looking for a recommendation from an experienced developer here. I have seen the storage options, but am unsure which would be best for just a few simple things. Everything I need could be represented in a 3 X n table wherein n is the number of spinners.

Since your requirements are so minimal, I think the shared preferences approach is probably the best option. If your requirements were more complicated, then a using a database would start to make more sense.
Using shared preferences for simple data like yours really is as simple as the example shown on the storage options page.

Storing Large Amounts of Dictionary-Like Data Within an Application in Java

I fear I may not be truly understanding the utility of database software like MySQL, so perhaps this is an easy question to answer.
I'm writing a program that stores and accesses a bestiary for use in the program. It is a stand-alone application, meaning that it will not connect to the internet or a database (which I am under the impression requires a connection to a server). Currently, I have an enormous .txt file that it parses via a simple pattern (Habitat is on every tenth line, starting with the seventh; name is on every tenth line, starting with the first; etc.) This is prone to parsing errors (problems with reading data that is unrecognizable with the specified encoding, as a lot of the data is copy/pasted by lazy data-entry-ists) and I just feel that parsing a giant .txt file every time I want data is horribly inefficient. Plus, I've never seen a deployed program that had a .txt laying around called "All of our important data.txt".
Are databases the answer? Can they be used simply in basic applications like this one? Writing a class for each animal seems silly. I've heard XML can help, too - but I know virtually nothing about it except that its a mark-up language.
In summary, I just don't know how to store large amounts of data within an application. A good analogy would be: How would you store data for a dictionary/encyclopedia application?

So you are saying that a standalone application without internet access cannot have a database connection? Well your Basic assumption that DB cannot exist in standalone apps is wrong. Today's web applications use Browser assisted SQL databases to store data. All you need is to experiment rather than speculate. If you need direction, start with light weight SQLite

While databases are undoubtedly a good idea for the kind of application you're describing, I'll throw another suggestion your way, which might suit you if your data doesn't necessarily need to change at all, and there's not a "huge" amount of it.
Java provides the ability to serialise objects, which you could use to persist and retrieve object instance data directly to/from files. Using this simple approach, you could:
Write code to parse your text file into a collection of serialisable application-specific object instances;
Serialise these instances to some file(s) which form part of your application;
De-serialise the objects into memory every time the application is run;
Write your own Java code to search and retrieve data from these objects yourself, for example using ordered collection structures with custom comparators.
This approach may suffice if you:
Don't expect your data to change;
Do expect it to always fit within memory on the JVMs you're expecting the application will be run on;
Don't require sophisticated querying abilities.
Even if one or more of the above things do not hold, it may still suit you to try this approach, so that your next step could be to use a so-called object-relational mapping tool like Hibernate or Castor to persist your serialisable data not in a file, but a database (XML or relational). From there, you can use the power of some database to maintain and query your data.

Inserting to and searching a large amount of data in Java

I am writing a program in Java which tracks data about baseball cards. I am trying to decide how to store the data persistently. I have been leaning towards storing the data in an XML file, but I am unfamiliar with XML APIs. (I have read some online tutorials and started experimenting with the classes in the javax.xml hierarchy.)
The software has to major use cases: the user will be able to add cards and search for cards.
When the user adds a card, I would like to immediately commit the data to the persistant storage. Does the standard API allow me to insert data in a random-access way (or even appending might be okay).
When the user searches for cards (for example, by a player's name), I would like to load a list from the storage without necessarily loading the whole file.
My biggest concern is that I need to store data for a large number of unique cards (in the neighborhood of thousands, possibly more). I don't want to store a list of all the cards in memory while the program is open. I haven't run any tests, but I believe that I could easily hit memory constraints.
XML might not be the best solution. However, I want to make it as simple as possible to install, so I am trying to avoid a full-blown database with JDBC or any third-party libraries.
So I guess I'm asking if I'm heading in the right direction and if so, where can I look to learn more about using XML in the way I want. If not, does anyone have suggestions about what other types of storage I could use to accomplish this task?

While I would certainly not discourage the use of XML, it does have some draw backs in your context.
"Does the standard API allow me to insert data in a random-access way"
Yes, in memory. You will have to save the entire model back to file though.
"When the user searches for cards (for example, by a player's name), I would like to load a list from the storage without necessarily loading the whole file"
Unless you're expected multiple users to be reading/writing the file, I'd probably pull the entire file/model into memory at load and keep it there until you want to save (doing periodical writes the background is still a good idea)
I don't want to store a list of all the cards in memory while the program is open. I haven't run any tests, but I believe that I could easily hit memory constraints
That would be my concern to. However, you could use a SAX parser to read the file into a custom model. This would reduce the memory overhead (as DOM parsers can be a little greedy with memory)
"However, I want to make it as simple as possible to install, so I am trying to avoid a full-blown database with JDBC"
I'd do some more research in this area. I (personally) use H2 and HSQLDB a lot for storage of large amount of data. These are small, personal database systems that don't require any additional installation (a Jar file linked to the program) or special server/services.
They make it really easy to build complex searches across the datastore that you would otherwise need to create yourself.
If you were to use XML, I would probably do one of three things
1 - If you're going to maintain the XML document in memory, I'd get familiar with XPath
(simple tutorial & Java's API) for searching.
2 - I'd create a "model" of the data using Objects to represent the various nodes, reading it in using a SAX. Writing may be a little more tricky.
3 - Use a simple SQL DB (and Object model) - it will simply the overall process (IMHO)
Additional
As if I hadn't dumped enough on you ;)
If you really want to XML (and again, I wouldn't discourage you from it), you might consider having a look a XML database style solution
Apache Xindice (apparently retired)
Or you could have a look at some other people think
Use XML as database in Java
Java: XML into a Database, whats the simplest way?
For example ;)