查询Hazelcast层次树结构

Question

我想弄清楚如何查询Hazelcast中的分层树结构。假设我有一个组织类:

public class Organization {
  private long id;
  private long parentId;
}

和我有一个User类:

public class NestupUser extends BaseEntity {
  private long id;
  private String firstName;
  private String lastName;
  private String email;
  private String password;
  private long organizationId;
}

现在，给定一个organizationId，我想要查找该组织的所有用户以及将该组织作为父级的所有组织，以及将这些组织作为父级的所有组织，等等

我假设这将作为某种MapReduce工作，但是有可能启动更多的MapReduce任务作为一个MapReduce的一部分吗?

感谢任何帮助。

Answer 1

我最终构建了一个非规范化的multimap，这样我就可以为给定的org id找到所有可访问的组织。这是在启动时设置结构的代码，如果它还没有被另一个节点设置。该类还实现了条目侦听器接口，以便在发生变化时获得回调，以保持结构同步(没有显示，但不难做到):

@PostConstruct
public void init() {
    IMap<String, Organization> organizationMap = organizationService.getMap();
    listenerRegistration = organizationMap.addLocalEntryListener(this);
    MultiMap<String, String> orgStructureMap = getOrgStructureMap();
    if (orgStructureMap.keySet().size() == 0) {
        Collection<Organization> all = organizationService.getAll(null);
        Set<String> visited = new HashSet<>();
        for (Organization next : all) {
            if (!visited.contains(next.getId())) {
                while (next != null && next.getParentId() != null && !visited.contains(next.getParentId())) {
                    next = next.getParentOrganization();
                }
                recurseReferences(visited, next);
            }
        }
    }
}
private void recurseReferences(Set<String> visited, Organization org) {
    addAllReferences(org);
    visited.add(org.getId());
    Set<Organization> childOrganizations = org.getChildOrganizations();
    for (Organization child : childOrganizations) {
        recurseReferences(visited, child);
    }
}
private void addAllReferences(Organization organization) {
    MultiMap<String, String> orgStructureMap = getOrgStructureMap();
    String parentId = organization.getParentId();
    if (parentId != null) {
        Set<Map.Entry<String, String>> entries = orgStructureMap.entrySet();
        for (Map.Entry<String, String> next : entries) {
            if (next.getValue().equals(parentId)) {
                orgStructureMap.put(next.getKey(),organization.getId());
            }
        }
    }
    orgStructureMap.put(organization.getId(), organization.getId());
}

private void removeAllReferences(Organization organization) {
    MultiMap<String, String> orgStructureMap = getOrgStructureMap();
    Set<String> keys = orgStructureMap.keySet();
    for (String key : keys) {
        orgStructureMap.remove(key, organization.getId());
    }
}