https://github.com/AzureAD/azure-activedirectory-library-for-java: Azure active directory library for Java gives you the ability to add Windows Azure Active Directory authentication to your web application with just a few lines of additional code. Using our ADAL SDKs you can quickly and easily extend your existing application to all the employees that use Windows Azure AD and Active Directory on-premises using Active Directory Federation Services, including Office365 customers.
  • MIT License
  • Microsoft Open Technologies, Inc. 
// Copyright (c) Microsoft Corporation.
// All rights reserved.
//
// This code is licensed under the MIT License.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files(the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions :
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package com.microsoft.aad.adal4j;

import com.nimbusds.oauth2.sdk.util.URLUtils;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.net.ssl.SSLSocketFactory;
import java.net.Proxy;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class DeviceCodeRequest {

    private final static Logger log = LoggerFactory.getLogger(DeviceCodeRequest.class);

    static DeviceCode execute(String url, String clientId, String resource, Map<String, String> clientDataHeaders,
                              final Proxy proxy, final SSLSocketFactory sslSocketFactory) throws Exception {
        Map<String, String> headers = new HashMap<>(clientDataHeaders);
        headers.put("Accept", "application/json");

        Map<String, List<String>> queryParameters = new HashMap<>();
        queryParameters.put("client_id", Collections.singletonList(clientId));
        queryParameters.put("resource", Collections.singletonList(resource));

        url = url + "?" + URLUtils.serializeParameters(queryParameters);

        final String json = HttpHelper.executeHttpGet(log, url, headers, proxy, sslSocketFactory);

        DeviceCode result;
        result = JsonHelper.convertJsonToObject(json, DeviceCode.class);

        result.setCorrelationId(headers.get(ClientDataHttpHeaders.CORRELATION_ID_HEADER_NAME));

        result.setClientId(clientId);
        result.setResource(resource);

        return result;
    }
}