Test.java

package com.github.fge.jsonschema;

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.ArrayNode;
import com.github.fge.jackson.JacksonUtils;
import com.github.fge.jackson.JsonLoader;
import com.github.fge.jackson.jsonpointer.JsonPointer;
import com.google.common.collect.Lists;

import java.io.IOException;
import java.util.List;

public final class Test
{
    private static final JsonNode QUERY;
    private static final JsonNode DATA;

    static {
        try {
            QUERY = JsonLoader.fromResource("/query.json");
            DATA = JsonLoader.fromResource("/data.json");
        } catch (IOException e) {
            throw new ExceptionInInitializerError(e);
        }
    }

    private static List<JsonPointer> queryParamsToPointers(final JsonNode params)
    {
        // The core query params must be an array, if it is not, bail out
        if (!params.isArray())
            throw new IllegalArgumentException("expected an array here");

        // jackson-coreutils depends on Guava, so we'll use that
        final List<JsonPointer> ret = Lists.newArrayList();

        for (final JsonNode node: params)
            addQueryParam(JsonPointer.empty(), ret, node);

        return ret;
    }

    private static void addQueryParam(final JsonPointer base,
        final List<JsonPointer> ret, final JsonNode node)
    {
        if (!node.isArray())
            throw new IllegalArgumentException("expected node to be an array");

        final int size = node.size();

        if (size == 0)
            throw new IllegalArgumentException("expected at least one element");

        if (arrayIsAllText(node)) {
            for (final JsonNode element: node)
                ret.add(base.append(element.textValue()));
            return;
        }

        final JsonNode first = node.get(0);

        if (!first.isTextual())
            throw new IllegalArgumentException("first node is not a string");

        final JsonPointer nextBase = base.append(first.textValue());

        if (size == 1) {
            ret.add(nextBase);
            return;
        }

        addQueryParam(nextBase, ret, node.get(1));
    }

    private static boolean arrayIsAllText(final JsonNode node)
    {
        for (final JsonNode element: node)
            if (!element.isTextual())
                return false;

        return true;
    }

    public static void main(final String... args)
    {
        final List<JsonPointer> pointers = queryParamsToPointers(QUERY);

        final ArrayNode array = JacksonUtils.nodeFactory().arrayNode();

        JsonNode node;

        for (final JsonPointer ptr: pointers) {
            node = ptr.get(DATA);
            if (node != null)
                array.add(node);
        }

        System.out.println(array);
    }
}