import java.util.*; public class SiteWrapper { private SiteA siteA; private SiteB siteB; public SiteWrapper(SiteA siteA, SiteB siteB) { this.siteA = siteA; this.siteB = siteB; } public List<Map<String, Object>> getSiteValue() { List<Map<String, Object>> productList = this.siteA.getValue(); productList.addAll(this.siteB.getValue()); return productList; } }