每次启动应用程序时如何制作一个新的数据库

Question

I'm making a swing application in which the user inputs a file (.html) and the application parses the data in the file and interprets into a database. Then there are a bunch of queries that are run on the database. This question tells what kind of queries I need to run over the database.

Following is how the

my questions are following -

1. How can I embed an empty database into my project, which is emptied every time the user quits the application? Basically I don't want the user to have to install a database separately or setup connections and stuff.

2. Will it be a better idea to NOT parse the html file into a database and rather convert it into a different data structure?

3. Since the results of queries over the database are supposed to be numbers only (I don't actually need to names of people or the Ticket#), I feel there is not much effort that needs to go into the database part. So basically I want to create a separate module (so to speak), that -- Takes the file from the application -- Parses the html into a database (or a different data structure) - pulls the numbers after running the appropriate queries -- gives those numbers to the application. Is this feasible?

Answer 1

Question 1

You'll probably have something like the following class in your app. Just overwrite the startup () method and perform your clean logic here.

public class YourSwingApp extends SingleFrameApplication {
/**
 * At startup clean the DB.
 */
@Override
protected void startup() {
    show(new YourSwingApp(this));
    // issue a set of 'truncate table' or 'delete from table' query here
    // you may want to create a Singleton to centralize the DB operation
}
}

Question 2

If you discard the data everytime the user quits yout application you probably don't need a persistence layer at all. Just keep the data model in memory and you're good. If you want something lighter than a DB, but persistent, you may want to use Object Serialization .

Question 3

The term "module" makes me think to OSGI which it may be an overkill here. Just separate the project in a lib and create an interface to implement. In this way your GUI can use the interface to get the results.