Sample code for retrieving an Oauth token for use with Bing translation APIs. http://msdn.microsoft.com/en-us/library/ff512421.aspx

BingOauth.java

import java.io.InputStreamReader;
import java.net.URI;
import java.util.List;

import com.google.common.base.Charsets;
import com.google.common.collect.Lists;
import com.google.common.io.CharStreams;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.json.simple.JSONObject;

/*
Thread safe singleton wrapper for Bing oauth token
*/
public class BingOauth {
  private static final int oauthTimeout = 10000;
  private static final String oauthEndpoint = "/v2/OAuth2-13/";
  private static final String oauthServerName = "datamarket.accesscontrol.windows.net";
  private static final String clientId = "-->YOUR_CLIENT_ID_HERE<--";
  private static final String clientSecret = "-->YOUR_CLIENT_SECRET_HERE<--";
  private static final String oauthScope = "http://api.microsofttranslator.com";
  private static final String oauthGrantType = "client_credentials";

  private static String oauthToken = null;

  /**
   * Thread safe lazy initializer for oauth token
   */
  public static String getOauthToken() {
    if (oauthToken == null) {
      synchronized (BingOauth.class) {
        if (oauthToken == null) {
          oauthToken = processOauthToken();
        }
      }
    }
    return oauthToken;
  }

  private static String processOauthToken() {
    String token = "";
    try {
      // Create request
      final HttpParams httpParams = new BasicHttpParams();
      HttpConnectionParams.setConnectionTimeout(httpParams, oauthTimeout);
      HttpClient client = new DefaultHttpClient(httpParams);
      HttpPost post = new HttpPost(getOauthUri());
      post.setEntity(getOauthBody());

      // Parse response
      HttpResponse response = client.execute(post);
      InputStreamReader reader = new InputStreamReader(response.getEntity().getContent(), Charsets.UTF_8);
      String responseBody = CharStreams.toString(reader);
      token = (new JSONObject(responseBody)).getString("access_token");
    } catch (Exception e) {
      System.out.println(String.format("Error processing oauth token:\n%s", e.toString()));
      e.printStackTrace();
    }
    return token;
  }

  private static URI getOauthUri() throws Exception {
    return new URI("https", oauthServerName, oauthEndpoint, null);
  }

  private static UrlEncodedFormEntity getOauthBody() throws Exception {
    List<NameValuePair> nameValuePairs = Lists.newArrayListWithCapacity(4);
    nameValuePairs.add(new BasicNameValuePair("client_id", clientId));
    nameValuePairs.add(new BasicNameValuePair("client_secret", clientSecret));
    nameValuePairs.add(new BasicNameValuePair("scope", oauthScope));
    nameValuePairs.add(new BasicNameValuePair("grant_type", oauthGrantType));
    return new UrlEncodedFormEntity(nameValuePairs);
  }
}

How do you manage this " token = (new JSONObject(responseBody)).getString("access_token");"?

When I try that I get the error "constructor JSONObject.JSONObject(Map) is not applicable"