Is it possible to be able to accept many matrix parameters in my rest URL without having to declare them in my code? - rest

Question

I am developing a Restful WS which does the simple job of querying a DB and bringing back some data. The table that is querying has around 20 columns.
I want to be able to filter the my returned records by using the matrix parameters in the WHERE clause of my SQL statements.
For Example:
Lets say that we have the table People with the columns id, firstname, lastname
I want the URL http://localhost:808/myservice/people;firstname=nick
to bring me back all the people with firstname equals Nick (select * from people where firsname='Nick').
First of all, is this the correct practice to do that?
Second, in my tablet that I have 20 columns I must create a method in my Java code that will contain all the possible matrix parameters (see below) or there is a better way to do this?
public Response getPeople(#MatrixParam("id") String id,
#MatrixParam("firstname") String firstname,
#MatrixParam("lastname") String lastname,
#MatrixParam("antoherColumn") String antoherColumn,
#MatrixParam("antoherColumn") String antoherColumn,
#MatrixParam("antoherColumn") String antoherColumn,
#MatrixParam("antoherColumn") String antoherColumn,
#MatrixParam("antoherColumn") String antoherColumn,
#MatrixParam("antoherColumn") String antoherColumn,
#MatrixParam("antoherColumn") String antoherColumn,
#MatrixParam("antoherColumn") String antoherColumn,) {
}
Thanks in advance

Answer 1

First of all do not create your query by concatenating strings:
String q = "select * from where firstName = " + firstName //BAD!
You are asking for troubles like SQL injection attacks. If you use JDBC, use query parameters.
Since probably you want to use GET request, you can stick to your approach, use query parameters instead (#QueryParam). You might also consider the following approach:
http://localhost:808/myservice/people?filter=firstname:nick,lastName:smith
and method:
public Response getPeople(#QueryParam("filter") String filter) {
//if filter is not null, tokenize filter string by ',' then by ':'
//to get needed parameters
}

Answer 2

You should use #BeanParam in order to map the MatrixParam to an object.
This way you can keep the resource pretty simple, but still have the possibility to add more matrix parameters. Also, adding matrix params doesn't involve changing the resource at all. The #BeanParam works also with #PathParam and #QueryParam.
Example:
Consider this:
http://localhost:8081/myservice/people;firstname=nick,lastName=smith/?offset=3&limit=4
and then the resource:
#GET
public Response get(#BeanParam Filter filter, #BeanParam Paging paging) {
return Response.ok("some results").build();
}
and the Filter class looks like:
public class Filter {
public Filter(#MatrixParam("firstname") String firstname, #MatrixParam("lastname") String lastname) {}
}
and the Paging class:
public class Paging {
public Paging(#QueryParam("offset") int offset, #QueryParam("limit") int limit) { }
}
You can also use more filters, like Filter1, Filter2 etc in order to keep it more modular.
Using the matrix parameters the biggest advantage is caching. It makes even more sense if you have more than one level in you API, like ../animals;size=medium/mamals;fur=white/?limit=3&offset=4, because the query params would apply otherwise to all collections.