Is it possible to store user defined objects in a SQLite database from Android? For example: I am creating one class and I want to store that class object in the database. Is it possible? If it is, how to proceed? On the Blackberry platform, I am able to store objects directly in persistent objects. Is it possible to do this with SQLite and Android?
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3 Answers
You'll need to be able to serialize your object into a byte stream and then recreate your object from a byte stream.
Then, just store that byte stream in your db.
EDIT: Read this article to learn about serialization in Java. It caters to the subject in a much better way than I would be able to by just giving some code snippets.
6 Comments
Kumar
can u pls provide me some code snippet to do serialization of object.
Prashast
I edited the answer and give a link to an article which teaches you how to do object serialization.
Budda
link leads to Oracle Java start page that has no information about serialization
Anirudh Ramanathan
Link rot. A little more detail would've been better!
Zelphir Kaltstahl
I was under the impression, that SQLite actually serves the purpose of quickly storing objects in a DB. I've used it for exactly that purpose in other applications. Is it really so, that we can't use SQLite like you'd use it in non-Android apps? Why use SQLite at all on Andorid then, if you have to do SQL Statements anyway? I don't get it. Why did they include SQLite then?
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Instead of storing them in SQLite why not store them in db4o, which is specifically designed for storing objects. A simple tutorial for sotring objects using db4o.
1 Comment
Matthias
DB4O is great in principle. It's super easy to use. BUT unfortunately it has many bugs and development/maintenance seems to have completely stopped. Very sad situation.
Use this code to convert your object to byte array and store it in your database as "BLOB"
public byte[] makebyte(Dataobject modeldata) {
try {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(baos);
oos.writeObject(modeldata);
byte[] employeeAsBytes = baos.toByteArray();
ByteArrayInputStream bais = new ByteArrayInputStream(employeeAsBytes);
return employeeAsBytes;
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
Use this code to convert your byte array to your object again
public Dataobject read(byte[] data) {
try {
ByteArrayInputStream baip = new ByteArrayInputStream(data);
ObjectInputStream ois = new ObjectInputStream(baip);
Dataobject dataobj = (Dataobject ) ois.readObject();
return dataobj ;
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
return null;
}
