openCMIS: Folder Hierarchy

CMIS imposes following constraints on Folder objects.

a.   Every folder object, except for one which is called the root folder, must have one and only one parent folder. The root folder does not have a parent.

b.   A cycle in folder containment relationships is not allowed. That is, a folder object cannot have itself as one of its descendant objects.

c.    A child object that is a folder object can itself be the parent object of other file-able objects.

d.   The root folder is a special folder such that it cannot be created, deleted, or moved using CMIS services.

e.   A non-folder object does not have any descendant objects.

Conventions used in folder hierarchy

Descendents: The child objects of a given folder object, their child objects, and grandchild objects, etc., are called descendant objects of the given folder object.

Tree: A folder object together with all its descendant objects are collectively called a tree.

File-able objects

A file-able object is the one, that is placed inside a folder. Following table summarizes, which base types are file-able.

Base Type	Is File-able
cmis:folder	MUST be file-able
cmis:document	MAY be file-able
cmis:relationship	MUST NOT be file-able
cmis:policy	MAY be file-able
cmis:item	MAY be file-able

Following application prints complete folder hierarchy from the root folder of the repository.

TestCmis.java

package com.sample.util;

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

import org.apache.chemistry.opencmis.client.api.FileableCmisObject;
import org.apache.chemistry.opencmis.client.api.Folder;
import org.apache.chemistry.opencmis.client.api.Session;
import org.apache.chemistry.opencmis.client.api.SessionFactory;
import org.apache.chemistry.opencmis.client.api.Tree;
import org.apache.chemistry.opencmis.client.runtime.SessionFactoryImpl;
import org.apache.chemistry.opencmis.commons.SessionParameter;
import org.apache.chemistry.opencmis.commons.enums.BindingType;

public class TestCmis {

 private static String serverURL = "http://localhost:8080/chemistry-opencmis-server-inmemory-1.1.0/browser";
 private static String repositoryId = "A1";

 private static Session getSession() {
  Map<String, String> parameters = new HashMap<>();
  parameters.put(SessionParameter.BINDING_TYPE, BindingType.BROWSER.value());

  parameters.put(SessionParameter.USER, "");
  parameters.put(SessionParameter.PASSWORD, "");

  parameters.put(SessionParameter.REPOSITORY_ID, repositoryId);
  parameters.put(SessionParameter.BROWSER_URL, serverURL);

  SessionFactory sessionFactory = SessionFactoryImpl.newInstance();
  return sessionFactory.createSession(parameters);
 }

 public static void printHierarchy(List<Tree<FileableCmisObject>> objects, String space) {

  for (Tree<FileableCmisObject> obj : objects) {
   FileableCmisObject fileableObj = obj.getItem();

   System.out.println(space + fileableObj.getName());
   printHierarchy(obj.getChildren(), " " + space);
  }
 }

 public static void main(String args[]) throws IOException {

  Session session = getSession();

  Folder rootFolder = session.getRootFolder();

  List<Tree<FileableCmisObject>> fileableCmisObjects = rootFolder.getDescendants(-1);

  printHierarchy(fileableCmisObjects, "");
 }

}

Output

My_Document-0-0
My_Document-0-1
My_Document-0-2
My_Folder-0-0
 My_Document-1-0
 My_Document-1-1
 My_Document-1-2
 My_Folder-1-0
  My_Document-2-0
  My_Document-2-1
  My_Document-2-2
  My_Folder-2-0
  My_Folder-2-1
 My_Folder-1-1
  My_Document-2-0
  My_Document-2-1
  My_Document-2-2
  My_Folder-2-0
  My_Folder-2-1
My_Folder-0-1
 My_Document-1-0
 My_Document-1-1
 My_Document-1-2
 My_Folder-1-0
  My_Document-2-0
  My_Document-2-1
  My_Document-2-2
  My_Folder-2-0
  My_Folder-2-1
 My_Folder-1-1
  My_Document-2-0
  My_Document-2-1
  My_Document-2-2
  My_Folder-2-0
  My_Folder-2-1

Previous                                                 Next                                                 Home