How to bind Double parameter with Play 2.0 routing

Question

I\'m learning myself Play 2.0 (Java API used) and would like to have a double/float parameter (for location coordinates), something like http://myfooapp.com/events/find?lati

Answer 1

Currently (in Play 2.0), Java binders only work with self-recursive types. That is, types looking like the following:

class Foo extends QueryStringBindable {
  …
}

So, if you want to define a binder for java.lang.Double, which is an existing type of Java, you need to wrap it in a self-recursive type. For example:

package util;

public class DoubleW implements QueryStringBindable {

    public Double value = null;

    @Override
    public Option bind(String key, Map data) {
        String[] vs = data.get(key);
        if (vs != null && vs.length > 0) {
            String v = vs[0];
            value = Double.parseDouble(v);
            return F.Some(this);
        }
        return F.None();
    }

    @Override
    public String unbind(String key) {
        return key + "=" + value;
    }

    @Override
    public String javascriptUnbind() {
         return value.toString();
    }

}

Then you can use it as follows in your application:

GET    /foo     controllers.Application.action(d: util.DoubleW)

public static Result action(DoubleW d) {
      …
}