How to authenticate with MS SharePoint to use its API with Java?

Question

I'm struggling to authenticate with MS SharePoint to use it's API. I've been googling and playing around with that problem for a while but somehow I can't figure out a solution. The most promising solution so far is based on this answer.

The dependencies I'm using are:

    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.4.1</version>
    </dependency>

This is my code:

public static void callRestEasyService() throws Exception {
    CredentialsProvider credsProvider = new BasicCredentialsProvider();
    credsProvider.setCredentials(
            new AuthScope(AuthScope.ANY),
            new NTCredentials("user", "password", "https://workstation.de", "domain.de"));

    CloseableHttpClient httpclient = HttpClients.custom()
            .setDefaultCredentialsProvider(credsProvider)
            .build();

    try {
        HttpGet httpget = new HttpGet("https://adress/_api/web/lists");

        System.out.println("Executing request " + httpget.getRequestLine());
        CloseableHttpResponse response = httpclient.execute(httpget);
        try {
            System.out.println("----------------------------------------");
            System.out.println(response.getStatusLine());
            EntityUtils.consume(response.getEntity());
        } finally {
            response.close();
        }
    } finally {
        httpclient.close();
    }

}

The code is quite self-explanatory I think, it is basically just what the linked answer suggests. My investigation showed that the best way to go for this problem are the NTCredentials. I also tried some other alternatives like the Basic Authentication but in all cases I receive:

HTTP/1.1 401 Unauthorized

I also tried using Samba JCIFS as an alternative NTLM engine.

Furthermore I'm a little bit scared that maybe the parameter for workstation (3rd parameter) or domain is filled in incorrectly by me. The documentation says:

workstation - The workstation the authentication request is originating from. Essentially, the computer name for this machine.

So I tried filling in the name of my machine but many examples on the web suggest that you use an URL that you are trying to authenticate with. This caused a little confusion for me but with none of the two options I could get it working.

Does anyone know why that is or has a possible solution or a workaround for that problem? Is it maybe possible that the SharePoint restricts the access via a programmed client? As far as I know it's at least not possible to disable the API from the SharePoint. Any ideas / thoughts to this?

LOLWTFasdasd asdad · Accepted Answer · 2017-08-31T08:26:44.330

I did not manage to get it going with the apache http client instead of this I tried running a cURL request from my java code to approach the SharePoint API, this worked fine instead. In case any one else has a similiar problem and wants to try a workaround this is my source code to run the cURL request:

ProcessBuilder pb = new ProcessBuilder(
            "curl",
            "https://mysharepoint/_api/web/lists/getbytitle('listName')/items",
            "-v",
            "--ntlm",
            "--negotiate",
            "-u",
            "user:password"
    );

    Process p = pb.start();
    InputStream is = p.getInputStream();
    return createHashMapForStaff(convertStreamToString(is));

The return line (createHashMapForStaff(convertStreamToString(is)) is just adapting the retrieved .XML from the SharePoint to my needs. The InputStream from the Process p is basically what you need.

How to authenticate with MS SharePoint to use its API with Java?

1 Answers1