Write a sling servlet which will return 10 child pages in json format, when called from any page

Use the sample code below. You will have to create a system user to get the resource resolver and restrict the number to 10.

import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import javax.servlet.Servlet;
import javax.servlet.ServletException;

import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.resource.LoginException;
import org.apache.sling.api.resource.ResourceResolver;
import org.apache.sling.api.resource.ResourceResolverFactory;
import org.apache.sling.api.servlets.SlingSafeMethodsServlet;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Reference;
import org.osgi.service.component.propertytypes.ServiceDescription;

import com.day.cq.wcm.api.Page;
import com.google.gson.JsonArray;

@Component(service = { Servlet.class },
			property={"sling.servlet.methods=get", "sling.servlet.path=/bin/MyServlet"})
@ServiceDescription("Simple Demo Servlet")
public class MyServlet extends SlingSafeMethodsServlet {

	@Reference
	ResourceResolverFactory resourceResolverFactory;
	ResourceResolver resourceResolver;
	List<String> children;

	private static final long serialVersionUID = 1L;

	@Override
	protected void doGet(final SlingHttpServletRequest req, final SlingHttpServletResponse resp)
			throws ServletException, IOException {
		Map<String, Object> param = new HashMap<String, Object>();
		param.put(ResourceResolverFactory.SUBSERVICE, "getResourceResolver");
		JsonArray array = new JsonArray();
		try {
			resourceResolver = resourceResolverFactory.getServiceResourceResolver(param);
			Page sourcePage = resourceResolver.getResource("/content/we-retail").adaptTo(Page.class);
			Iterator<Page> listChildren = sourcePage.listChildren(null, true);
			while (listChildren.hasNext()) {
				array.add(listChildren.next().getPath());
			}
		} catch (LoginException e) {

		}
		resp.setContentType("application/json");
		resp.setCharacterEncoding("UTF-8");
		resp.getWriter().print(array.toString());
	}
}