OAuth 2.0 service invocation

The OAuth client redirects the resource owner or user to the WebSphere Application Server OAuth 2.0 Authorization Service by adding its client id, client secret, state, redirect URI, and the optional scopes.

https://host_name:port_number/oauth2/endpoint/provider_name/authorize

or

https://host_name:port_number/oauth2/declarativeEndpoint/provider_name/authorize

The OAuth client requests an access token from the WebSphere Application Server OAuth 2.0 token endpoint by adding authorization_code grant type, authorization code, redirect_url, and client_id as request parameters.

https://host_name:port_number/oauth2/endpoint/provider_name/token

The following example shows the constructions of the URIs when using authorization code, and the use of the access token to access web resources:

String charset = "UTF-8";
String param1 = "code";

if (isAuthorizationCode){
  String query = String.format("response_type=%s&
                               client_id=%s&
                               client_secret=%s&
                               state=%s&
                               redirect_uri=%s&
                               scope=%s",
                               URLEncoder.encode(param1, charset),
                               URLEncoder.encode(clientId, charset),
                               URLEncoder.encode(clientSecret, charset),
                               URLEncoder.encode(state, charset),
                               URLEncoder.encode(redirectURI, charset),
                               URLEncoder.encode(scope, charset));
  String s = authorizationEndPoint + "?" + query;
  System.out.println("Visit: " + s + "\nand grant permission");
  System.out.print("Now enter the OAuth code you have received in redirect uri :");
  BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
  String code = br.readLine();
  param1 = "authorization_code";
  query = String.format("grant_type=%s&
                        code=%s&
                        client_id=%s&
                        client_secret=%s&
                        state=%s&
                        redirect_uri=%s&
                        scope=%s",
                        URLEncoder.encode(param1, charset),
                        URLEncoder.encode(code, charset),
                        URLEncoder.encode(clientId, charset),
                        URLEncoder.encode(clientSecret, charset),
                        URLEncoder.encode(state, charset),
                        URLEncoder.encode(redirectURI, charset),
                        URLEncoder.encode(scope, charset));
  URL url = new URL(tokenEndPoint);
  HttpsURLConnection con = (HttpsURLConnection)url. openConnection();
  con.setRequestProperty("Content-Type", "application/x-www-form-urlencoded;charset="  + charset);
  con.setDoOutput(true);
  con.setRequestMethod("POST");
  OutputStream output = null;
  try {
    output = con.getOutputStream();
    output.write(query.getBytes(charset));
    output.flush();
  } finally {
    if (output != null) try {
      output.close();
    } catch (IOException logOrIgnore) {}
  }
  con.connect();
  System.out.println("response message is = " + con.getResponseMessage());
  // read the output from the server
  BufferedReader reader = null;
  StringBuilder stringBuilder;
  reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
  stringBuilder = new StringBuilder();
  String line = null;
  try {
    while ((line = reader.readLine()) != null) {
      stringBuilder.append(line + "\n");
    }
  } finally {
    if (reader != null) try {
      reader.close();
    } catch (IOException logOrIgnore) {}
  }
  String tokenResponse = stringBuilder.toString();
  System.out.println ("response is = " + tokenResponse);
  JSONObject json = JSONObject.parse(tokenResponse);
  if (json.containsKey("access_token")) {
    accessToken = (String)json.get("access_token");
    this.accessToken = accessToken;
  }
  if (json.containsKey("refresh_token")) {
    refreshToken = (String)json.get("refresh_token");
  }
  //sendRequestForAccessToken(query);
  if (accessToken != null) {
    String query = String.format("access_token=%s",
                                 URLEncoder.encode(accessToken, charset));
    URL urlResource = new URL(resourceEndPoint);
    HttpsURLConnection conn = (HttpsURLConnection) urlResource.openConnection();
    conn.setRequestMethod("POST");
    conn.setRequestProperty("Content-type", "application/x-www-form-urlencoded");
    conn.setDoOutput(true);
    output = null;
    try {
      output = conn.getOutputStream();
      output.write(query.getBytes(charset));
      output.flush();
    } finally {
      if (output != null) try {
        output.close();
      } catch (IOException logOrIgnore) {}
    }
    conn.connect();
    System.out.println("response to the resource request is = " + conn.getResponseMessage ());
    reader = null;
    if(conn.getResponseCode()>=200 && conn.getResponseCode() < 400) {
      reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
      stringBuilder = new StringBuilder();
      String line = null;
      try {
        while ((line = reader.readLine()) != null) {
          stringBuilder.append(line + "\n");
        }
      } finally {
        if (reader != null) try {
          reader.close();
        } catch (IOException  logOrIgnore) {}
      }
      System.out.println ("response message to the request resource is = " +  stringBuilder.toString());
    } else {
      isValidResponse = false;
    }
  }
}