To transform a Page<Object> to Map<String,Object>

ApiService.java

package org.jboss.xavier.integrations.jpa.service;

import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import javax.inject.Named;

import org.apache.camel.Exchange;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.data.domain.Page;
import org.springframework.stereotype.Component;

@Component
public class ApiService {
    @Value("${camel.component.servlet.mapping.context-path}")
    String contextPath;

    public Map<String,Object> mapToCustomPage(Exchange exchange) {
        Page<Object> page = (Page<Object>) exchange.getIn().getBody();
        Map<String, Object> result = new HashMap<>();

        Map<String, Object> meta = new HashMap<>();
        meta.put("count", page.getTotalElements());
        meta.put("limit", page.getSize());
        meta.put("offset", page.getNumber());
        result.put("meta", meta);

        result.put("data", page.getContent());

        Map<String, Object> links = new HashMap<>();
        links.put("first", getURLLink(exchange.getIn().getHeader(Exchange.HTTP_URI, String.class)+exchange.getIn().getHeader(Exchange.HTTP_QUERY, String.class), 0, page.getSize()));
        links.put("last", getURLLink(exchange.getIn().getHeader(Exchange.HTTP_URI, String.class)+exchange.getIn().getHeader(Exchange.HTTP_QUERY, String.class), page.getTotalPages() -1, page.getSize()));
        result.put("links", links);

        return result;
    }

    private String getURLLink(String url, int offset, int limit) {
        int indexOfQuestion = url.indexOf("?");

        if (indexOfQuestion >= 0) {
          String query = url.substring(indexOfQuestion);
          String urlNoParams = url.substring(0, indexOfQuestion);
          String params = Arrays.asList(query.split("&")).stream().filter(e -> !e.startsWith("limit") && !e.startsWith("offset")).collect(Collectors.joining());
          url = urlNoParams + ((params.isEmpty()) ? "?" : "?" + params + "&");
        } else {
          url = url + "?";
        }
        url = url + "limit=" + limit;
        url = url + "&offset=" + offset;

        return url;
    }
}


<rest path="/mappings">
<description>Mapping REST API</description>
<get uri="/flag-assessment">
    <param name="offset" type="query" defaultValue="0" required="false" description="Define the page requested" />
    <param name="limit" type="query" defaultValue="10" required="false" description="Define the size of the requested page" /> <!-- ${{pagination.defaults.flag-assessment.limit}} -->
    <route id="mappings-flag-assessment-findAll">
        <!-- RBAC check start-->
        <setHeader headerName="${type:org.jboss.xavier.integrations.rbac.RBACRouteBuilder.RBAC_ENDPOINT_RESOURCE_NAME}"><constant>mappings</constant></setHeader>
        <setHeader headerName="${type:org.jboss.xavier.integrations.rbac.RBACRouteBuilder.RBAC_ENDPOINT_RESOURCE_PERMISSION}"><constant>read</constant></setHeader>
        <to uri="direct:check-rbac-permissions" />
        <!-- RBAC check end-->

        <bean ref="flagAssessmentService" method="findAll(${header.offset}, ${header.limit})" />
        <bean ref="apiService" method="mapToCustomPage(${exchange})"/> 
    </route>
</get>
</rest>