Added comments

azd/src/main/java/org/azd/git/GitApi.java

@@ -40,7 +40,7 @@ public class GitApi implements GitDetails {
      * @throws ConnectionException A connection object should be created with Azure DevOps organization name, personal access token
      * and project. This validates the connection object and throws exception if it is not provided.
      * @throws AzDException Default Api Exception handler.
-     * @return git repository object
+     * @return git repository object {@link Repository}
      */
     @Override
     public Repository createRepository(String repositoryName, String projectId) throws ConnectionException, AzDException {

azd/src/main/java/org/azd/oauth/OAuthApi.java

@@ -10,8 +10,14 @@
 
 import java.util.LinkedHashMap;
 
+/***
+ * OAuth Api class to authorize access to REST API
+ */
 public class OAuthApi {
 
+    /***
+     * Deserialize JSON response to POJO
+     */
     private static final JsonMapper MAPPER = new JsonMapper();
     private static final String AREA = "accounts";
 
@@ -20,13 +26,24 @@ public class OAuthApi {
     static {
         try {
             VSTS_BASE_URL = Client.getLocationUrl(AREA,null);
-        } catch (ConnectionException |AzDException e) {
+        } catch (ConnectionException | AzDException e) {
 
         }
     }
 
+    /***
+     * Default constructor
+     */
     public OAuthApi() {}
 
+    /***
+     * Generate the authorization endpoint with client id, state, scope and redirection url.
+     * @param clientId The ID assigned to your app when it was registered
+     * @param state Can be any value. Typically a generated string value that correlates the callback with its associated authorization request.
+     * @param scope Scopes registered with the app. Space separated. See https://docs.microsoft.com/en-us/azure/devops/integrate/get-started/authentication/oauth?view=azure-devops#scopes
+     * @param redirectUrl Callback URL for your app. Must exactly match the URL registered with the app.
+     * @return The authorization endpoint to authorize your app
+     */
     public static String getAuthorizationEndpoint(String clientId, String state, String scope, String redirectUrl) {
 
         var queryString = new LinkedHashMap<String, Object>(){{
@@ -48,11 +65,25 @@ public static String getAuthorizationEndpoint(String clientId, String state, Str
         return stringBuilder.toString();
     }
 
+    /**
+     * Helps to create a query string from given key and value
+     * @param key pass the key of the HashMap
+     * @param value pass the value of the HasMap
+     * @return query string
+     */
     private static String getQueryString(String key, Object value) {
         return "&" + key + "=" + value;
     }
 
-
+    /***
+     * Now you use the authorization code to request an access token for the user.
+     * Your service must make a service-to-service HTTP request to Azure DevOps Services.
+     * @param appSecret URL encoded client secret acquired when the app was registered
+     * @param authCode URL encoded "code" provided via the code query parameter to your callback URL
+     * @param callbackUrl callback URL registered with the app
+     * @return AuthorizedToken object {@link AuthorizedToken}
+     * @throws AzDException Default Api Exception handler.
+     */
     public static AuthorizedToken getAccessToken(String appSecret, String authCode, String callbackUrl) throws AzDException {
 
         StringBuilder stringBuilder = new StringBuilder();
@@ -77,6 +108,16 @@ public static AuthorizedToken getAccessToken(String appSecret, String authCode,
         return res;
     }
 
+    /***
+     * If a user's access token expires, you can use the refresh token that they acquired in the authorization flow to get a new access token.
+     * @param appSecret URL encoded client secret acquired when the app was registered
+     * @param authCode URL encoded "code" provided via the code query parameter to your callback URL
+     * @param callbackUrl callback URL registered with the app
+     * @return AuthorizedToken object {@link AuthorizedToken}
+     * @throws ConnectionException A connection object should be created with Azure DevOps organization name, personal access token
+     * and project. This validates the connection object and throws exception if it is not provided.
+     * @throws AzDException Default Api Exception handler.
+     */
     public static AuthorizedToken getRefreshToken(String appSecret, String authCode, String callbackUrl) throws AzDException, ConnectionException {
 
         StringBuilder stringBuilder = new StringBuilder();
@@ -99,6 +140,11 @@ public static AuthorizedToken getRefreshToken(String appSecret, String authCode,
         return res;
     }
 
+    /***
+     * Check if the access token has expired.
+     * @param authorizedToken authorized token object {@link AuthorizedToken}
+     * @return True if the token has expired. {@link Boolean}
+     */
     public static boolean hasTokenExpired(AuthorizedToken authorizedToken) {
         return authorizedToken.getReceivedTimestamp() < 1629897097271L || (authorizedToken.getReceivedTimestamp() + authorizedToken.getExpiresIn()*1000) < System.currentTimeMillis();
     }