I have a microservice I am designing for getting "Book" information, and one of the capabilities is to query Solr and fuse it with some DB results that I queried.

I am looking for, what I am calling a "query maker pattern" something that will generate dynamic solr queries. The idea in my head was a class like

public class Query {
    public Attribute[]; 
}

public class Attribute {
    public String type; 
    public String value;
}

But I'm not sure what the best way to generate dynamic queries in an object oriented way. There is a bad way of having a bunch of functions that append strings like:

public function String addSort(String value, Boolean isAscending){
    return value + "+" + (isAscending ? "asc" : "desc");
}
public function String addFacet(String facetName){
    etc etc
}

It would be best to have something like a toString() function for the Query object, and then using that as a the request to Solr?