Saving and retrieving state of checkbox fields from database

Our application is web-based. Our tools of trade are: Java, JDK1.6, Apache Tomcat v6.0.10, PostgreSQL v8.2.3.

We've a page/screen in the application that has got approx. 20 - 30 checkboxes, which just only denotes yes/no state of the fields.

My question here is, just before I settle down myself on my own design/architecture, I wanted to bounce my implementation with the community and get opinion/advice on how others are looking at/handling this type of design considerations.

My solution/design: Creating a table (USERPREFERENCE) with 3 columns: EMPLOYEEID, FIELDID, STATE. Define/designate each checkbox field by a Unique ID/constant (1, 2, 3, ..., 30). Hence, there would be 20 - 30 entries for each user in this table. Is this normal or is there any different/better way of handling this effectively at the database-level? Also, how do I map the state of 20 - 30 fields (stored row-wise) from database to a JavaBean object automatically, so that it becomes 开发者_开发技巧ease in handling back-and-forth at Java level?

USERPREFERENCE table looks like:

EMPLOYEEID | FIELDID | STATE
100        |   1     | true
100        |   2     | true
100        |   3     | false
...        |  ...    |  ...

Any advice/design alternatives are welcome and appreciated.

NOTE: We would also be developing another 4 page/screen with the same functionality having 20 - 30 checkbox fields in each screen.

UPDATE: Please take this into account: The fields are not fixed, new fields may get added in future.

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If the fields are of a fixed length and you have a value for each field for most of your entities (EMPLOYEEID) I would opt for separate boolean columns for each field. It's more efficient from two points of view:

• storage: you don't have to store a (EMPLOYEEID, FIELDID) key for each value (and PostgreSQL is smart about storing booleans)
• ease of use: it's easy to query and map the values to your model