Question

I have a simple RESTful web service that print “Hello World !”
I’m using NetBeans and the code looks like:

package resource;

import javax.ws.rs.core.Context;
import javax.ws.rs.core.UriInfo;
import javax.ws.rs.Consumes;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.GET;
import javax.ws.rs.Produces;


@Path("simple")
public class SimpleResource {

    @Context
    private UriInfo context;

    /** Creates a new instance of SimpleResource */
    public SimpleResource() {
    }

    @GET
    @Produces("application/xml")
    public String getXml() {
        //TODO return proper representation object
        return "<greeting>Hello World !</greeting>";
    }

    @PUT
    @Consumes("application/xml")
    public void putXml(String content) {
    }
}

I call this web service from this URL : http://localhost:8080/WebService/resources/simple.
Now, I want to send a parameter to this web service, then print this parameter after the “Hello world” message.

How can we do that?

Thanks!

Answer 1

The two main ways of handling a parameter in REST are via parsing the path and via extracting the query part.

Path parameters

These handle this case — /foo/{fooID} — where {fooID} is a template that will be replaced by the parameter you want:

@GET
@Produces("text/plain")
@Path("/foo/{fooID}")
public String getFoo(@PathParam("fooID") String id) {
    // ...
}

These are great for the case where you can consider the parameter to be describing a resource.

Query parameters

These handle this case — /?foo=ID — just like you’d get from doing traditional form processing:

@GET
@Produces("text/plain")
@Path("/")
public String getFoo(@QueryParam("foo") String id) {
    // ...
}

These are great for the case where you consider the parameter to be describing an adjunct to the resource, and not the resource itself. The @FormParam annotation is extremely similar, except it is for handling a POSTed form instead of GET-style parameters

Other types of parameters

There are other types of parameter handling supported by the JAX-RS spec (matrix parameters, header parameters, cookie parameters) which all work in about the same way to the programmer, but are rarer or more specialized in use. A reasonable place to start exploring the details is the JAX-RS javadoc itself, as that has useful links.