List users in Java apps using Microsoft Graph

In this article, you extend the application you created in Build Java apps with Microsoft Graph and app-only authentication with Microsoft Graph user APIs. You use Microsoft Graph to list users in your organization.

1. Open Graph.java and add the following function to the Graph class.

   public static UserCollectionResponse getUsers() throws Exception {
       // Ensure client isn't null
       if (_appClient == null) {
           throw new Exception("Graph has not been initialized for app-only auth");
       }
   
       return _appClient.users().get(requestConfig -> {
           requestConfig.queryParameters.select = new String[] { "displayName", "id", "mail" };
           requestConfig.queryParameters.top = 25;
           requestConfig.queryParameters.orderby = new String[] { "displayName" };
       });
   }
   

2. Replace the empty listUsers function in App.java with the following.

   private static void listUsers() {
       try {
           final UserCollectionResponse users = Graph.getUsers();
   
           // Output each user's details
           for (User user: users.getValue()) {
               System.out.println("User: " + user.getDisplayName());
               System.out.println("  ID: " + user.getId());
               System.out.println("  Email: " + user.getMail());
           }
   
           final Boolean moreUsersAvailable = users.getOdataNextLink() != null;
           System.out.println("\nMore users available? " + moreUsersAvailable);
       } catch (Exception e) {
           System.out.println("Error getting users");
           System.out.println(e.getMessage());
       }
   }
   

3. Run the app, sign in, and choose option 4 to list users.

   Please choose one of the following options:
   0. Exit
   1. Display access token
   2. List users
   3. Make a Graph call
   2
   User: Adele Vance
     ID: 05fb57bf-2653-4396-846d-2f210a91d9cf
     Email: AdeleV@contoso.com
   User: Alex Wilber
     ID: a36fe267-a437-4d24-b39e-7344774d606c
     Email: AlexW@contoso.com
   User: Allan Deyoung
     ID: 54cebbaa-2c56-47ec-b878-c8ff309746b0
     Email: AllanD@contoso.com
   User: Bianca Pisani
     ID: 9a7dcbd0-72f0-48a9-a9fa-03cd46641d49
     Email: NO EMAIL
   User: Brian Johnson (TAILSPIN)
     ID: a8989e40-be57-4c2e-bf0b-7cdc471e9cc4
     Email: BrianJ@contoso.com
   
   ...
   
   More users available? True
   

Code explained

Consider the code in the getUsers function.

Accessing a collection

This method returns a collection of users. Most APIs in Microsoft Graph that return a collection don't return all available results in a single response. Instead, they use paging to return a portion of the results while providing a method for clients to request the next page.

Default page sizes

APIs that use paging implement a default page size. For users, the default value is 10. Clients can request more (or less) by using the $top query parameter. In getUsers, adding $top is accomplished with the top property in the request configuration.

Getting subsequent pages

If there are more results available on the server, collection responses include an @odata.nextLink property with an API URL to access the next page. The Java client library provides the getOdataNextLink method on collection response objects. If this method returns non-null, there are more results available.

Sorting collections

The function uses the orderBy property on the request configuration to request results sorted by the users' display names. This property adds the $orderby query parameter to the API call.

Next step