AEM QueryBuilder API: Where do I put my custom created predicate?

After looking into code-base and testing out random things, here's how I was able to replicate the same to my AEM instance:

1. Step 1: As suggested by @ganthira1, create a raw project using the following command:

mvn -B archetype:generate \
 -D archetypeGroupId=com.adobe.granite.archetypes \
 -D archetypeArtifactId=aem-project-archetype \
 -D archetypeVersion=23 \
 -D aemVersion=6.5.0 \
 -D appTitle="My Site" \
 -D appId="mysite" \
 -D groupId="com.mysite" \
 -D frontendModule=general \
 -D includeExamples=n

Make sure to change the names as per your need. 

Step 2: Write the custom predicate as required: (and save it in src/main/java/com/mysite/core/<FOLDERNAME>/CustomCasePredicate.java)

```

package com.mysite.core.search;

import java.util.Comparator;
import javax.jcr.query.Row;
import org.apache.sling.api.resource.ValueMap;
import org.osgi.service.component.annotations.Component;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.day.cq.search.Predicate;
import com.day.cq.search.eval.AbstractPredicateEvaluator;
import com.day.cq.search.eval.EvaluationContext;
/**
 * Custom class to support case sensitive compare
 * path=
 * type=
 * customcase.property=
 * {optional} customcase.fulltext=
 * customcase.case=upper/lower/UPPER/LOWER/no_case/NO_CASE
 * orderby=customcase
 *
 */
@Component(factory="com.day.cq.search.eval.PredicateEvaluator/customcase")
public class CustomCasePredicate extends AbstractPredicateEvaluator {
    private static final Logger logger = LoggerFactory.getLogger(CustomCasePredicate.class);
    public static final String PROPERTY = "property";
    public static final String FULL_TEXT = "fulltext";
    public static final String CASE = "case";
    public static final String LOWER_CASE = "lower";
    public static final String UPPER_CASE = "upper";
    public static final String NO_CASE = "no_case";
    @Override
    public boolean includes(Predicate predicate, Row row,
                            EvaluationContext context) {
        if(predicate.hasNonEmptyValue(PROPERTY)){
            return true;
        }
        return super.includes(predicate, row, context);
    }

    @Override
    public String getXPathExpression(Predicate predicate,
                                     EvaluationContext context) {
        if(!predicate.hasNonEmptyValue(PROPERTY)){
            return null;
        }
        if(predicate.hasNonEmptyValue(PROPERTY) && null==predicate.get(FULL_TEXT)){
            return super.getXPathExpression(predicate, context);
        }
        if(predicate.get(CASE).equalsIgnoreCase(LOWER_CASE)){
            return "jcr:like(fn:lower-case(" + predicate.get(PROPERTY) + "),'" + predicate.get(FULL_TEXT) + "')";
        }
        if(predicate.get(CASE).equalsIgnoreCase(UPPER_CASE)){
            return "jcr:like(fn:upper-case(" + predicate.get(PROPERTY) + "),'" + predicate.get(FULL_TEXT) + "')";
        }
        if(predicate.get(CASE).equalsIgnoreCase(NO_CASE)){
            return "jcr:like(fn:lower-case(" + predicate.get(PROPERTY) + "),'" + predicate.get(FULL_TEXT).toLowerCase()+ "')";
        }
        return super.getXPathExpression(predicate, context);
    }

    @Override
    public Comparator<Row> getOrderByComparator(final Predicate predicate, final EvaluationContext context) {
        return new Comparator<Row>() {
            public int compare(Row r1, Row r2) {
                String[] property1;
                String[] property2;
                try {
                    if(null!=r1&&null!=r2&&null!=predicate.get(PROPERTY)){
                        ValueMap valueMap1 = context.getResource(r1).adaptTo(ValueMap.class);
                        ValueMap valueMap2 = context.getResource(r2).adaptTo(ValueMap.class);
                        property1 = valueMap1.get(predicate.get(PROPERTY),String[].class);
                        property2 =valueMap2.get(predicate.get(PROPERTY),String[].class);
                        boolean isCompare = null!=property1 && null!=property2;
                        if(isCompare) logger.debug("value    "+ property1[0] + "   "+ property2[0]);
                        if(isCompare && predicate.get(CASE).equalsIgnoreCase(LOWER_CASE)){
                            return property1[0].toLowerCase().compareTo(property2[0].toLowerCase());
                        }
                        if(isCompare && predicate.get(CASE).equalsIgnoreCase(UPPER_CASE)){
                            return property1[0].toUpperCase().compareTo(property2[0].toUpperCase());
                        }else{
                            return isCompare ? property1[0].compareToIgnoreCase(property2[0]):1;
                        }
                    }
                } catch (Exception e) {
                    logger.error(e.getMessage());
                    e.printStackTrace();
                }
                return 1;
            }

        };
    }

}

The above is an example however you can use the same to implement case insensetivity fulltext search in a given property and you can use the same with groups as well.

Step 3: Run the command: mvn clean install -PautoInstallPackage to deploy it to the local instance. You can also view methods to deploy the same to cloud as well.

I had been looking here and there for the same and in case this is helpful to you do upvote so that it reaches the right people when required. Please note that this repo:https://github.com/Adobe-Marketing-Cloud/aem-search-custom-predicate-evaluator only supports upto AEM 6.4. If you're on 6.5+ mostly this approach would work like a charm.