EAP AKA Challenge response not accepted by server

Correct the parameter of calling the method of generate IMSI EAP
and also format the code style

Bug: 177544547
Test: atest EapAkaResponseTest and Verified CSpire VoWiFi entitlement flow with this CL.
Summary
-------
arm64-v8a service-entitlement-tests: Passed: 28, Failed: 0, Ignored: 0, Assumption Failed: 0,
Change-Id: I28766caf800139f6c4244be5a65b4f508c539fe0
Merged-In: I28766caf800139f6c4244be5a65b4f508c539fe0
(cherry picked from commit fb4a25e1de19e98950d3adb6041818e70a5eb8fe)

14 files changed, 387 insertions, 257 deletions

diff --git a/java/com/android/libraries/entitlement/EsimOdsaOperation.java b/java/com/android/libraries/entitlement/EsimOdsaOperation.java
index d7d23ac..ce764f2 100644
--- a/java/com/android/libraries/entitlement/EsimOdsaOperation.java
+++ b/java/com/android/libraries/entitlement/EsimOdsaOperation.java
@@ -24,22 +24,38 @@ import com.google.auto.value.AutoValue;
  */
 @AutoValue
 public abstract class EsimOdsaOperation {
-    /** OSDA operation: CheckEligibility. */
+    /**
+     * OSDA operation: CheckEligibility.
+     */
     public static final String OPERATION_CHECK_ELIGIBILITY = "CheckEligibility";
-    /** OSDA operation: ManageSubscription. */
+    /**
+     * OSDA operation: ManageSubscription.
+     */
     public static final String OPERATION_MANAGE_SUBSCRIPTION = "ManageSubscription";
-    /** OSDA operation: ManageService. */
+    /**
+     * OSDA operation: ManageService.
+     */
     public static final String OPERATION_MANAGE_SERVICE = "ManageService";
-    /** OSDA operation: AcquireConfiguration. */
+    /**
+     * OSDA operation: AcquireConfiguration.
+     */
     public static final String OPERATION_ACQUIRE_CONFIGURATION = "AcquireConfiguration";
 
-    /** Indicates that operation_type is not set. */
+    /**
+     * Indicates that operation_type is not set.
+     */
     static final int OPERATION_TYPE_NOT_SET = -1;
-    /** To activate a subscription, used by {@link #OPERATION_MANAGE_SUBSCRIPTION}. */
+    /**
+     * To activate a subscription, used by {@link #OPERATION_MANAGE_SUBSCRIPTION}.
+     */
     public static final int OPERATION_TYPE_SUBSCRIBE = 0;
-    /** To cancel a subscription, used by {@link #OPERATION_MANAGE_SUBSCRIPTION}. */
+    /**
+     * To cancel a subscription, used by {@link #OPERATION_MANAGE_SUBSCRIPTION}.
+     */
     public static final int OPERATION_TYPE_UNSUBSCRIBE = 1;
-    /** To manage an existing subscription, for {@link #OPERATION_MANAGE_SUBSCRIPTION}. */
+    /**
+     * To manage an existing subscription, for {@link #OPERATION_MANAGE_SUBSCRIPTION}.
+     */
     public static final int OPERATION_TYPE_CHANGE_SUBSCRIPTION = 2;
     /**
      * To transfer a subscription from an existing device, used by {@link
@@ -51,21 +67,32 @@ public abstract class EsimOdsaOperation {
      * {@link #OPERATION_MANAGE_SUBSCRIPTION}.
      */
     public static final int OPERATION_TYPE_UPDATE_SUBSCRIPTION = 4;
-    /** To activate a service, used by {@link #OPERATION_MANAGE_SERVICE}. */
+    /**
+     * To activate a service, used by {@link #OPERATION_MANAGE_SERVICE}.
+     */
     public static final int OPERATION_TYPE_ACTIVATE_SERVICE = 10;
-    /** To deactivate a service, used by {@link #OPERATION_MANAGE_SERVICE}. */
+    /**
+     * To deactivate a service, used by {@link #OPERATION_MANAGE_SERVICE}.
+     */
     public static final int OPERATION_TYPE_DEACTIVATE_SERVICE = 11;
 
-    /** Indicates the companion device carries the same MSISDN as the primary device. */
+    /**
+     * Indicates the companion device carries the same MSISDN as the primary device.
+     */
     public static final String COMPANION_SERVICE_SHAERED_NUMBER = "SharedNumber";
-    /** Indicates the companion device carries a different MSISDN as the primary device. */
+    /**
+     * Indicates the companion device carries a different MSISDN as the primary device.
+     */
     public static final String COMPANION_SERVICE_DIFFERENT_NUMBER = "DiffNumber";
 
-    /** Returns the eSIM ODSA operation. Used by HTTP parameter "operation". */
+    /**
+     * Returns the eSIM ODSA operation. Used by HTTP parameter "operation".
+     */
     public abstract String operation();
 
     /**
-     * Returns the detiled type of the eSIM ODSA operation. Used by HTTP parameter "operation_type".
+     * Returns the detiled type of the eSIM ODSA operation. Used by HTTP parameter
+     * "operation_type".
      */
     public abstract int operationType();
 
@@ -81,7 +108,8 @@ public abstract class EsimOdsaOperation {
     public abstract String companionTerminalVendor();
 
     /**
-     * Returns the model of the companion device. Used by HTTP parameter "companion_terminal_model".
+     * Returns the model of the companion device. Used by HTTP parameter
+     * "companion_terminal_model".
      */
     public abstract String companionTerminalModel();
 
@@ -104,16 +132,20 @@ public abstract class EsimOdsaOperation {
     public abstract String companionTerminalService();
 
     /**
-     * Returns the ICCID of the companion device. Used by HTTP parameter "companion_terminal_iccid".
+     * Returns the ICCID of the companion device. Used by HTTP parameter
+     * "companion_terminal_iccid".
      */
     public abstract String companionTerminalIccid();
 
     /**
-     * Returns the ICCID of the companion device. Used by HTTP parameter "companion_terminal_iccid".
+     * Returns the ICCID of the companion device. Used by HTTP parameter
+     * "companion_terminal_iccid".
      */
     public abstract String companionTerminalEid();
 
-    /** Returns the ICCID of the primary device eSIM. Used by HTTP parameter "terminal_eid". */
+    /**
+     * Returns the ICCID of the primary device eSIM. Used by HTTP parameter "terminal_eid".
+     */
     public abstract String terminalIccid();
 
     /**
@@ -128,7 +160,9 @@ public abstract class EsimOdsaOperation {
      */
     public abstract String targetTerminalId();
 
-    /** Returns the ICCID primary device eSIM. Used by HTTP parameter "target_terminal_iccid". */
+    /**
+     * Returns the ICCID primary device eSIM. Used by HTTP parameter "target_terminal_iccid".
+     */
     public abstract String targetTerminalIccid();
 
     /**
@@ -137,7 +171,9 @@ public abstract class EsimOdsaOperation {
      */
     public abstract String targetTerminalEid();
 
-    /** Returns a new {@link Builder} object. */
+    /**
+     * Returns a new {@link Builder} object.
+     */
     public static Builder builder() {
         return new AutoValue_EsimOdsaOperation.Builder().setOperationType(OPERATION_TYPE_NOT_SET);
     }
@@ -146,10 +182,8 @@ public abstract class EsimOdsaOperation {
      * Builder.
      *
      * <p>For ODSA, the rule of which parameters are required varies or each
-     * operation/opeation_type.
-     * The Javadoc below gives high-level description, but please refer to GMSA spec TS.43 section
-     * 6.2
-     * for details.
+     * operation/opeation_type. The Javadoc below gives high-level description, but please refer to
+     * GMSA spec TS.43 section 6.2 for details.
      */
     @AutoValue.Builder
     public abstract static class Builder {
diff --git a/java/com/android/libraries/entitlement/ServiceEntitlement.java b/java/com/android/libraries/entitlement/ServiceEntitlement.java
index abf6ace..be50605 100644
--- a/java/com/android/libraries/entitlement/ServiceEntitlement.java
+++ b/java/com/android/libraries/entitlement/ServiceEntitlement.java
@@ -18,28 +18,38 @@ package com.android.libraries.entitlement;
 
 import android.content.Context;
 
+import androidx.annotation.Nullable;
+
 import com.android.libraries.entitlement.eapaka.EapAkaApi;
 
 import com.google.common.annotations.VisibleForTesting;
 
 import java.util.List;
 
-import androidx.annotation.Nullable;
-
 /**
  * Implemnets protocol for carrier service entitlement configuration query and operation, based on
  * GSMA TS.43 spec.
  */
 public class ServiceEntitlement {
-    /** App ID for Voice-Over-LTE entitlement. */
+    /**
+     * App ID for Voice-Over-LTE entitlement.
+     */
     public static final String APP_VOLTE = "ap2003";
-    /** App ID for Voice-Over-WiFi entitlement. */
+    /**
+     * App ID for Voice-Over-WiFi entitlement.
+     */
     public static final String APP_VOWIFI = "ap2004";
-    /** App ID for SMS-Over-IP entitlement. */
+    /**
+     * App ID for SMS-Over-IP entitlement.
+     */
     public static final String APP_SMSOIP = "ap2005";
-    /** App ID for on device service activation (OSDA) for companion device. */
+    /**
+     * App ID for on device service activation (OSDA) for companion device.
+     */
     public static final String APP_ODSA_COMPANION = "ap2006";
-    /** App ID for on device service activation (OSDA) for primary device. */
+    /**
+     * App ID for on device service activation (OSDA) for primary device.
+     */
     public static final String APP_ODSA_PRIMARY = "ap2009";
 
     private final Context context;
@@ -54,9 +64,9 @@ public class ServiceEntitlement {
      * @param carrierConfig     carrier specific configs used in the queries and operations.
      * @param simSubscriptionId the subscroption ID of the carrier's SIM on device. This indicates
      *                          which SIM to retrieve IMEI/IMSI from and perform EAP-AKA
-     *                          authentication with. See {@link
-     *                          android.telephony.SubscriptionManager} for how to get the
-     *                          subscroption ID.
+     *                          authentication with. See
+     *                          {@link android.telephony.SubscriptionManager}
+     *                          for how to get the subscroption ID.
      */
     public ServiceEntitlement(Context context, CarrierConfig carrierConfig, int simSubscriptionId) {
         this.context = context;
@@ -78,10 +88,8 @@ public class ServiceEntitlement {
      * <p>Supported {@code appId}: {@link #APP_VOLTE}, {@link #APP_VOWIFI}, {@link #APP_SMSOIP}.
      *
      * <p>This method sends an HTTP GET request to entitlement server, responds to EAP-AKA
-     * challenge
-     * if needed, and returns the raw configuration doc as a string. The following parameters are
-     * set
-     * in the HTTP request:
+     * challenge if needed, and returns the raw configuration doc as a string. The following
+     * parameters are set in the HTTP request:
      *
      * <ul>
      * <li>"app": {@code appId}
@@ -119,9 +127,8 @@ public class ServiceEntitlement {
 
     /**
      * Retrieves service entitlement configurations for multiple app IDs in one HTTP
-     * request/response.
-     * For on device service activation (ODSA) of eSIM for companion/primary devices, use {@link
-     * #performEsimOdsa} instead.
+     * request/response. For on device service activation (ODSA) of eSIM for companion/primary
+     * devices, use {@link #performEsimOdsa} instead.
      *
      * <p>Same with {@link #queryEntitlementStatus(String, ServiceEntitlementRequest)} except that
      * multiple "app" parameters will be set in the HTTP request, in the order as they appear in
@@ -138,10 +145,10 @@ public class ServiceEntitlement {
      *
      * <p>Supported {@code appId}: {@link #APP_ODSA_COMPANION}, {@link #APP_ODSA_PRIMARY}.
      *
-     * <p>Similar to {@link #queryEntitlementStatus(String, ServiceEntitlementRequest)}, this method
-     * sends an HTTP GET request to entitlement server, responds to EAP-AKA challenge if needed, and
-     * returns the raw configuration doc as a string. Additional parameters from {@code operation}
-     * are set to the HTTP request. See {@link EsimOdsaOperation} for details.
+     * <p>Similar to {@link #queryEntitlementStatus(String, ServiceEntitlementRequest)}, this
+     * method sends an HTTP GET request to entitlement server, responds to EAP-AKA challenge if
+     * needed, and returns the raw configuration doc as a string. Additional parameters from {@code
+     * operation} are set to the HTTP request. See {@link EsimOdsaOperation} for details.
      */
     public String performEsimOdsa(
             String appId, ServiceEntitlementRequest request, EsimOdsaOperation operation)
diff --git a/java/com/android/libraries/entitlement/ServiceEntitlementException.java b/java/com/android/libraries/entitlement/ServiceEntitlementException.java
index 499a032..fa476ce 100644
--- a/java/com/android/libraries/entitlement/ServiceEntitlementException.java
+++ b/java/com/android/libraries/entitlement/ServiceEntitlementException.java
@@ -16,18 +16,22 @@
 
 package com.android.libraries.entitlement;
 
-/** Indicates errors happened in retrieving service entitlement configuration. */
+/**
+ * Indicates errors happened in retrieving service entitlement configuration.
+ */
 public class ServiceEntitlementException extends Exception {
-    /** Unknown error. */
+    /**
+     * Unknown error.
+     */
     public static final int ERROR_UNKNOWN = 0;
-    /** Android telephony is unable to provide info like IMSI, e.g. when modem crashed. */
+    /**
+     * Android telephony is unable to provide info like IMSI, e.g. when modem crashed.
+     */
     public static final int ERROR_PHONE_NOT_AVAILABLE = 1;
     /**
      * SIM not returning a response to the EAP-AKA challenge, e.g. when the challenge is invalid.
-     * This
-     * can happen only when an embedded EAP-AKA challange is conducted, as per GMSA spec TS.43
-     * section
-     * 2.6.1.
+     * This can happen only when an embedded EAP-AKA challange is conducted, as per GMSA spec TS.43
+     * section 2.6.1.
      */
     public static final int ERROR_ICC_AUTHENTICATION_NOT_AVAILABLE = 2;
     /**
@@ -51,13 +55,17 @@ public class ServiceEntitlementException extends Exception {
         // TODO(b/177544547): add implementation
     }
 
-    /** Returns the error code, see {@link #ERROR_*}. */
+    /**
+     * Returns the error code, see {@link #ERROR_*}.
+     */
     public int getErrorCode() {
         // TODO(b/177544547): add implementation
         return ERROR_UNKNOWN;
     }
 
-    /** Returns the HTTP status code returned by entitlement server; 0 if unavailable. */
+    /**
+     * Returns the HTTP status code returned by entitlement server; 0 if unavailable.
+     */
     public int getHttpStatus() {
         // TODO(b/177544547): add implementation
         return ERROR_SEVER_NOT_CONNECTABLE;
diff --git a/java/com/android/libraries/entitlement/ServiceEntitlementRequest.java b/java/com/android/libraries/entitlement/ServiceEntitlementRequest.java
index 6bbfee6..9db5246 100644
--- a/java/com/android/libraries/entitlement/ServiceEntitlementRequest.java
+++ b/java/com/android/libraries/entitlement/ServiceEntitlementRequest.java
@@ -21,12 +21,18 @@ import android.os.Build.VERSION;
 
 import com.google.auto.value.AutoValue;
 
-/** Service entitlement HTTP request parameters, as defiend in GSMA spec TS.43 section 2.2. */
+/**
+ * Service entitlement HTTP request parameters, as defiend in GSMA spec TS.43 section 2.2.
+ */
 @AutoValue
 public abstract class ServiceEntitlementRequest {
-    /** Disables notification token. */
+    /**
+     * Disables notification token.
+     */
     public static final int NOTICATION_ACTION_DISABLE = 0;
-    /** Enables FCM notification token. */
+    /**
+     * Enables FCM notification token.
+     */
     public static final int NOTICATION_ACTION_ENABLE_FCM = 2;
 
     /**
@@ -41,7 +47,9 @@ public abstract class ServiceEntitlementRequest {
      */
     public abstract String entitlementVersion();
 
-    /** Returns the authentication token. Used by HTTP parameter "token". */
+    /**
+     * Returns the authentication token. Used by HTTP parameter "token".
+     */
     public abstract String authenticationToken();
 
     /**
@@ -49,13 +57,19 @@ public abstract class ServiceEntitlementRequest {
      */
     public abstract String terminalId();
 
-    /** Returns the OEM of the device. Used by HTTP parameter "terminal_vendor". */
+    /**
+     * Returns the OEM of the device. Used by HTTP parameter "terminal_vendor".
+     */
     public abstract String terminalVendor();
 
-    /** Returns the model of the device. Used by HTTP parameter "terminal_model". */
+    /**
+     * Returns the model of the device. Used by HTTP parameter "terminal_model".
+     */
     public abstract String terminalModel();
 
-    /** Returns the software version of the device. Used by HTTP parameter "terminal_sw_version". */
+    /**
+     * Returns the software version of the device. Used by HTTP parameter "terminal_sw_version".
+     */
     public abstract String terminalSoftwareVersion();
 
     /**
@@ -72,8 +86,7 @@ public abstract class ServiceEntitlementRequest {
 
     /**
      * Returns the FCM registration token used to register for entitlement configuration request
-     * from
-     * network. Used by HTTP parameter "notif_token".
+     * from network. Used by HTTP parameter "notif_token".
      */
     public abstract String notificationToken();
 
@@ -86,7 +99,9 @@ public abstract class ServiceEntitlementRequest {
      */
     public abstract int notificationAction();
 
-    /** Returns a new {@link Builder} object. */
+    /**
+     * Returns a new {@link Builder} object.
+     */
     public static Builder builder() {
         return new AutoValue_ServiceEntitlementRequest.Builder()
                 .setConfigurationVersion(0)
@@ -102,7 +117,9 @@ public abstract class ServiceEntitlementRequest {
                 .setNotificationAction(NOTICATION_ACTION_ENABLE_FCM);
     }
 
-    /** Builder. */
+    /**
+     * Builder.
+     */
     @AutoValue.Builder
     public abstract static class Builder {
         /**
@@ -130,7 +147,8 @@ public abstract class ServiceEntitlementRequest {
         public abstract Builder setAuthenticationToken(String value);
 
         /**
-         * Sets the unique identifier of the device like IMEI. Used by HTTP parameter "terminal_id".
+         * Sets the unique identifier of the device like IMEI. Used by HTTP parameter
+         * "terminal_id".
          *
          * <p>If not set, will use the device IMEI.
          */
@@ -175,8 +193,7 @@ public abstract class ServiceEntitlementRequest {
 
         /**
          * Sets the FCM registration token used to register for entitlement configuration request
-         * from
-         * network. Used by HTTP parameter "notif_token".
+         * from network. Used by HTTP parameter "notif_token".
          *
          * <p>Optional.
          */
diff --git a/java/com/android/libraries/entitlement/eapaka/EapAkaApi.java b/java/com/android/libraries/entitlement/eapaka/EapAkaApi.java
index b9eaadd..a145ebc 100644
--- a/java/com/android/libraries/entitlement/eapaka/EapAkaApi.java
+++ b/java/com/android/libraries/entitlement/eapaka/EapAkaApi.java
@@ -22,6 +22,8 @@ import android.telephony.TelephonyManager;
 import android.text.TextUtils;
 import android.util.Log;
 
+import androidx.annotation.Nullable;
+
 import com.android.libraries.entitlement.ServiceEntitlementException;
 import com.android.libraries.entitlement.ServiceEntitlementRequest;
 import com.android.libraries.entitlement.http.HttpClient;
@@ -30,14 +32,12 @@ import com.android.libraries.entitlement.http.HttpConstants.RequestMethod;
 import com.android.libraries.entitlement.http.HttpRequest;
 import com.android.libraries.entitlement.http.HttpResponse;
 
-import org.json.JSONException;
-import org.json.JSONObject;
-
-import androidx.annotation.Nullable;
-
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.net.HttpHeaders;
 
+import org.json.JSONException;
+import org.json.JSONObject;
+
 import java.net.CookieHandler;
 import java.net.CookieManager;
 
@@ -46,52 +46,72 @@ public class EapAkaApi {
 
     public static final String EAP_CHALLENGE_RESPONSE = "eap-relay-packet";
 
-    /** Current version of the entitlement configuration. */
+    /**
+     * Current version of the entitlement configuration.
+     */
     private static final String VERS = "vers";
-    /** Version of the entitlement configuration. */
+    /**
+     * Version of the entitlement configuration.
+     */
     private static final String ENTITLEMENT_VERSION = "entitlement_version";
     /**
-     * Unique identifier for the device. Refer to {@link
-     * android.telephony.TelephonyManager#getImei()}.
+     * Unique identifier for the device. Refer to
+     * {@link android.telephony.TelephonyManager#getImei()}.
      */
     private static final String TERMINAL_ID = "terminal_id";
-    /** Device manufacturer. */
+    /**
+     * Device manufacturer.
+     */
     private static final String TERMINAL_VENDOR = "terminal_vendor";
-    /** Device model. */
+    /**
+     * Device model.
+     */
     private static final String TERMINAL_MODEL = "terminal_model";
-    /** Device software version. */
+    /**
+     * Device software version.
+     */
     private static final String TERMIAL_SW_VERSION = "terminal_sw_version";
-    /** Identifier for the requested entitlement. */
+    /**
+     * Identifier for the requested entitlement.
+     */
     private static final String APP = "app";
-    /** NAI needed for EAP-AKA authentication. */
+    /**
+     * NAI needed for EAP-AKA authentication.
+     */
     private static final String EAP_ID = "EAP_ID";
 
     private static final String IMSI = "IMSI";
     private static final String TOKEN = "token";
-    /** Action for the notification registration token. */
+    /**
+     * Action for the notification registration token.
+     */
     private static final String NOTIF_ACTION = "notif_action";
-    /** Attribute name of the notification registration token. */
+    /**
+     * Attribute name of the notification registration token.
+     */
     private static final String NOTIF_TOKEN = "notif_token";
-    /** Attribute name of the app version. */
+    /**
+     * Attribute name of the app version.
+     */
     private static final String APP_VERSION = "app_version";
-    /** Attribute name of the app name. */
+    /**
+     * Attribute name of the app name.
+     */
     private static final String APP_NAME = "app_name";
 
-    private final Context context;
-    private final int simSubscriptionId;
-    private final HttpClient httpClient;
+    private final Context mContext;
+    private final int mSimSubscriptionId;
+    private final HttpClient mHttpClient;
 
     public EapAkaApi(Context context, int simSubscriptionId) {
-        this.context = context;
-        this.simSubscriptionId = simSubscriptionId;
-        this.httpClient = new HttpClient();
+        this(context, simSubscriptionId, new HttpClient());
     }
 
     @VisibleForTesting
     EapAkaApi(Context context, int simSubscriptionId, HttpClient httpClient) {
-        this.context = context;
-        this.simSubscriptionId = simSubscriptionId;
-        this.httpClient = httpClient;
+        this.mContext = context;
+        this.mSimSubscriptionId = simSubscriptionId;
+        this.mHttpClient = httpClient;
     }
 
     /**
@@ -117,7 +137,7 @@ public class EapAkaApi {
                                 "application/vnd.gsma.eap-relay.v1.0+json, text/vnd.wap"
                                         + ".connectivity-xml")
                         .build();
-        HttpResponse response = httpClient.request(httpRequest);
+        HttpResponse response = mHttpClient.request(httpRequest);
         if (response == null) {
             throw new ServiceEntitlementException("Null http response");
         }
@@ -128,7 +148,7 @@ public class EapAkaApi {
                 String akaChallengeResponse =
                         new EapAkaResponse(
                                 new JSONObject(response.body()).getString(EAP_CHALLENGE_RESPONSE))
-                                .getEapAkaChallengeResponse(context, simSubscriptionId);
+                                .getEapAkaChallengeResponse(mContext, mSimSubscriptionId);
                 JSONObject postData = new JSONObject();
                 postData.put(EAP_CHALLENGE_RESPONSE, akaChallengeResponse);
                 return challengeResponse(postData, serverUrl);
@@ -160,7 +180,7 @@ public class EapAkaApi {
                                 "application/vnd.gsma.eap-relay.v1.0+json")
                         .build();
 
-        HttpResponse response = httpClient.request(request);
+        HttpResponse response = mHttpClient.request(request);
         if (response == null || response.contentType() != ContentType.XML) {
             throw new ServiceEntitlementException("Unexpected http response.");
         }
@@ -171,16 +191,15 @@ public class EapAkaApi {
     @VisibleForTesting
     String entitlementStatusUrl(
             String appId, String serverUrl, ServiceEntitlementRequest request) {
-        TelephonyManager telephonyManager =
-                (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
-        telephonyManager = telephonyManager.createForSubscriptionId(simSubscriptionId);
+        TelephonyManager telephonyManager = mContext.getSystemService(
+                TelephonyManager.class).createForSubscriptionId(mSimSubscriptionId);
         Uri.Builder urlBuilder = Uri.parse(serverUrl).buildUpon();
         if (TextUtils.isEmpty(request.authenticationToken())) {
             // EAP_ID required for initial AuthN
             urlBuilder.appendQueryParameter(
                     EAP_ID,
                     getImsiEap(telephonyManager.getSimOperator(),
-                               telephonyManager.getSubscriberId()));
+                            telephonyManager.getSubscriberId()));
         } else {
             // IMSI and token required for fast AuthN.
             urlBuilder
diff --git a/java/com/android/libraries/entitlement/eapaka/EapAkaResponse.java b/java/com/android/libraries/entitlement/eapaka/EapAkaResponse.java
index 8f4f138..1d9be2b 100644
--- a/java/com/android/libraries/entitlement/eapaka/EapAkaResponse.java
+++ b/java/com/android/libraries/entitlement/eapaka/EapAkaResponse.java
@@ -22,6 +22,8 @@ import android.text.TextUtils;
 import android.util.Base64;
 import android.util.Log;
 
+import androidx.annotation.Nullable;
+
 import com.android.libraries.entitlement.ServiceEntitlementException;
 import com.android.libraries.entitlement.eapaka.utils.BytesConverter;
 
@@ -33,9 +35,10 @@ import java.security.NoSuchAlgorithmException;
 import javax.crypto.Mac;
 import javax.crypto.spec.SecretKeySpec;
 
-import androidx.annotation.Nullable;
-
-/** Generate the response of EAP-AKA token challenge for initial AUTN. */
+/**
+ * Generate the response of EAP-AKA token challenge. Refer to RFC 4187 Section 8.1 Message
+ * Format/RFC 3748 Session 4 EAP Packet Format.
+ */
 class EapAkaResponse {
     private static final String TAG = "ServiceEntitlement";
 
@@ -49,45 +52,52 @@ class EapAkaResponse {
     private static final byte ATTRIBUTE_RES = 0x03;
     private static final byte ATTRIBUTE_MAC = 0x0B;
     private static final String ALGORITHM_HMAC_SHA1 = "HmacSHA1";
-    private static final int RAND_LENGTH = 20;
-    private static final int AUTN_LENGTH = 20;
+    private static final int ATTRIBUTE_LENGTH = 20;
     private static final int SHA1_OUTPUT_LENGTH = 20;
 
-    /** RAND length 16. */
     private static final byte RAND_LEN = 0x10;
-    /** AUTN length 16. */
     private static final byte AUTN_LEN = 0x10;
 
-    /* 1 for Request, 2 for Response*/
-    private byte code = -1;
-    /* The identifier of Response must same as Request */
-    private byte identifier = -1;
-    /* The total length of full EAP-AKA message, include code, identifier, ... */
-    private int length = -1;
-    /* In EAP-AKA, the Type field is set to 23 */
-    private byte type = -1;
-    /* SubType for AKA-Challenge should be 1 */
-    private byte subType = -1;
-    /* The value of AT_AUTN, network authentication token */
-    private byte[] autn;
-    /* The value of AT_RAND, RAND random number*/
-    private byte[] rand;
-
-    private boolean valid;
+    /**
+     * {@link #CODE_REQUEST} for Request, {@link #CODE_RESPONSE} for Response
+     */
+    private byte mCode = -1;
+    /**
+     * The identifier of Response must same as Request
+     */
+    private byte mIdentifier = -1;
+    /**
+     * The total length of full EAP-AKA message, include code, identifier, ...
+     */
+    private int mLength = -1;
+    /**
+     * In EAP-AKA, the Type field is set to {@link #TYPE_EAP_AKA}
+     */
+    private byte mType = -1;
+    /**
+     * SubType for AKA-Challenge should be {@link #SUBTYPE_AKA_CHALLENGE}
+     */
+    private byte mSubType = -1;
+    /**
+     * The value of AT_AUTN, network authentication token
+     */
+    private byte[] mAutn;
+    /**
+     * The value of AT_RAND, RAND random number
+     */
+    private byte[] mRand;
 
-    @VisibleForTesting
-    static String challengeResponseForTesting;
+    private boolean mValid;
 
     public EapAkaResponse(String eapAkaChallenge) {
         try {
             parseEapAkaChallengeRequest(eapAkaChallenge);
         } catch (Exception e) {
             Log.e(TAG, "parseEapAkaChallengeRequest Exception:", e);
-            valid = false;
+            mValid = false;
         }
     }
 
-    /** Refer to RFC 4187 Section 8.1 Message Format/RFC 3748 Session 4 EAP Packet Format. */
     private void parseEapAkaChallengeRequest(String request) {
         if (TextUtils.isEmpty(request)) {
             return;
@@ -96,7 +106,7 @@ class EapAkaResponse {
         try {
             byte[] data = Base64.decode(request, Base64.DEFAULT);
             if (parseEapAkaHeader(data) && parseRandAndAutn(data)) {
-                valid = true;
+                mValid = true;
             } else {
                 Log.d(TAG, "Invalid data!");
             }
@@ -115,29 +125,29 @@ class EapAkaResponse {
         if (data.length <= EAP_AKA_HEADER_LENGTH) {
             return false;
         }
-        code = data[0];
-        identifier = data[1];
-        length = ((data[2] & 0xff) << 8) | (data[3] & 0xff);
-        type = data[4];
-        subType = data[5];
+        mCode = data[0];
+        mIdentifier = data[1];
+        mLength = ((data[2] & 0xff) << 8) | (data[3] & 0xff);
+        mType = data[4];
+        mSubType = data[5];
 
         // valid header
-        if (code != CODE_REQUEST
-                || length != data.length
-                || type != TYPE_EAP_AKA
-                || subType != SUBTYPE_AKA_CHALLENGE) {
+        if (mCode != CODE_REQUEST
+                || mLength != data.length
+                || mType != TYPE_EAP_AKA
+                || mSubType != SUBTYPE_AKA_CHALLENGE) {
             Log.d(
                     TAG,
                     "Invalid EAP-AKA Header, code="
-                            + code
+                            + mCode
                             + ", length="
-                            + length
+                            + mLength
                             + ", real length="
                             + data.length
                             + ", type="
-                            + type
+                            + mType
                             + ", subType="
-                            + subType);
+                            + mSubType);
             return false;
         }
 
@@ -172,26 +182,26 @@ class EapAkaResponse {
 
             // see RFC 4187 section 11 for attribute type
             if (attributeType == ATTRIBUTE_RAND) {
-                if (length != RAND_LENGTH) {
+                if (length != ATTRIBUTE_LENGTH) {
                     Log.d(TAG, "AT_RAND length is " + length);
                     return false;
                 }
-                rand = new byte[16];
-                System.arraycopy(data, index + 4, rand, 0, 16);
+                mRand = new byte[16];
+                System.arraycopy(data, index + 4, mRand, 0, 16);
             } else if (attributeType == ATTRIBUTE_AUTN) {
-                if (length != AUTN_LENGTH) {
+                if (length != ATTRIBUTE_LENGTH) {
                     Log.d(TAG, "AT_AUTN length is " + length);
                     return false;
                 }
-                autn = new byte[16];
-                System.arraycopy(data, index + 4, autn, 0, 16);
+                mAutn = new byte[16];
+                System.arraycopy(data, index + 4, mAutn, 0, 16);
             }
 
             index += length;
-        } // while
+        }
 
         // check has AT_RAND and AT_AUTH
-        if (rand == null || autn == null) {
+        if (mRand == null || mAutn == null) {
             Log.d(TAG, "Invalid Type Datas!");
             return false;
         }
@@ -201,16 +211,11 @@ class EapAkaResponse {
 
     /**
      * Returns EAP-AKA challenge response message which generated with SIM EAP-AKA authentication
-     * with
-     * network provided EAP-AKA challenge request message.
+     * with network provided EAP-AKA challenge request message.
      */
     public String getEapAkaChallengeResponse(Context context, int simSubscriptionId)
             throws ServiceEntitlementException {
-        if(challengeResponseForTesting != null) {
-            return challengeResponseForTesting;
-        }
-
-        if (!valid) {
+        if (!mValid) {
             throw new ServiceEntitlementException("EAP-AKA Challenge message not valid!");
         }
 
@@ -230,8 +235,8 @@ class EapAkaResponse {
         // generate master key
         MasterKey mk =
                 MasterKey.create(
-                        EapAkaApi.getImsiEap(telephonyManager.getSubscriberId(),
-                                telephonyManager.getSimOperator()),
+                        EapAkaApi.getImsiEap(telephonyManager.getSimOperator(),
+                                telephonyManager.getSubscriberId()),
                         securityContext.getIk(),
                         securityContext.getCk());
         // K_aut is the key used to calculate MAC
@@ -250,25 +255,30 @@ class EapAkaResponse {
         return Base64.encodeToString(challengeResponse, Base64.NO_WRAP).trim();
     }
 
-    /** Returns Base64 encoded GSM/3G security context for SIM Authentication request. */
+    /**
+     * Returns Base64 encoded GSM/3G security context for SIM Authentication request.
+     */
     @Nullable
     private String getSimAuthChallengeData() {
-        if (!valid) {
+        if (!mValid) {
             return null;
         }
 
         byte[] challengeData = new byte[RAND_LEN + AUTN_LEN + 2];
         challengeData[0] = RAND_LEN;
-        System.arraycopy(rand, 0, challengeData, 1, RAND_LEN);
+        System.arraycopy(mRand, 0, challengeData, 1, RAND_LEN);
         challengeData[RAND_LEN + 1] = AUTN_LEN;
-        System.arraycopy(autn, 0, challengeData, RAND_LEN + 2, AUTN_LEN);
+        System.arraycopy(mAutn, 0, challengeData, RAND_LEN + 2, AUTN_LEN);
 
         return Base64.encodeToString(challengeData, Base64.NO_WRAP).trim();
     }
 
-    /** Returns EAP-AKA Challenge response message byte array data or null if failed to generate. */
+    /**
+     * Returns EAP-AKA Challenge response message or {@code null} if failed to generate.
+     */
+    @VisibleForTesting
     @Nullable
-    public byte[] generateEapAkaChallengeResponse(@Nullable byte[] res, byte[] aut) {
+    byte[] generateEapAkaChallengeResponse(@Nullable byte[] res, @Nullable byte[] aut) {
         if (res == null || aut == null) {
             return null;
         }
@@ -301,7 +311,7 @@ class EapAkaResponse {
         // set up header
         message[0] = CODE_RESPONSE;
         // Identifier need to same with request
-        message[1] = identifier;
+        message[1] = mIdentifier;
         // length include entire EAP-AKA message
         byte[] lengthBytes = BytesConverter.convertIntegerTo4Bytes(message.length);
         message[2] = lengthBytes[2];
diff --git a/java/com/android/libraries/entitlement/eapaka/EapAkaSecurityContext.java b/java/com/android/libraries/entitlement/eapaka/EapAkaSecurityContext.java
index bb451fd..925e258 100644
--- a/java/com/android/libraries/entitlement/eapaka/EapAkaSecurityContext.java
+++ b/java/com/android/libraries/entitlement/eapaka/EapAkaSecurityContext.java
@@ -23,7 +23,7 @@ import android.util.Log;
 import com.android.libraries.entitlement.ServiceEntitlementException;
 
 /**
- * Provide format to handle request/response SIM Authentication with GSM/3G security context.
+ * Provides format to handle request/response SIM Authentication with GSM/3G security context.
  *
  * <p>Reference ETSI TS 131 102, Section 7.1.2.1 GSM/3G security context.
  */
@@ -32,19 +32,21 @@ class EapAkaSecurityContext {
 
     private static final byte RESPONSE_TAG_SUCCESS = (byte) 0xDB;
 
-    private boolean valid;
+    private boolean mValid;
 
     /* Authentication result from SIM */
-    private byte[] res;
+    private byte[] mRes;
     /* Cipher Key */
-    private byte[] ck;
+    private byte[] mCk;
     /* Integrity Key */
-    private byte[] ik;
+    private byte[] mIk;
 
     private EapAkaSecurityContext() {
     }
 
-    /** Provide {@link EapAkaSecurityContext} from response data. */
+    /**
+     * Provide {@link EapAkaSecurityContext} from response data.
+     */
     public static EapAkaSecurityContext from(String response)
             throws ServiceEntitlementException {
         EapAkaSecurityContext securityContext = new EapAkaSecurityContext();
@@ -56,11 +58,9 @@ class EapAkaSecurityContext {
     }
 
     /**
-     * Parses SIM EAP-AKA Authentication responsed data and returns valid {@link
-     * EapAkaSecurityContext}
-     * for successful data; otherwise, returns invalid.
+     * Parses SIM EAP-AKA Authentication responded data.
      */
-    void parseResponseData(String response) {
+    private void parseResponseData(String response) {
         if (TextUtils.isEmpty(response)) {
             Log.d(TAG, "parseResponseData but input empty data!");
             return;
@@ -84,27 +84,27 @@ class EapAkaSecurityContext {
 
             // Parse RES
             index++; // move to RES length byte
-            res = parseTag(index, data);
-            if (res == null) {
+            mRes = parseTag(index, data);
+            if (mRes == null) {
                 Log.d(TAG, "Invalid data! can't parse RES!");
                 return;
             }
             // Parse CK
-            index += res.length + 1; // move to CK length byte
-            ck = parseTag(index, data);
-            if (ck == null) {
+            index += mRes.length + 1; // move to CK length byte
+            mCk = parseTag(index, data);
+            if (mCk == null) {
                 Log.d(TAG, "Invalid data! can't parse CK!");
                 return;
             }
             // Parse IK
-            index += ck.length + 1; // move to IK length byte
-            ik = parseTag(index, data);
-            if (ik == null) {
+            index += mCk.length + 1; // move to IK length byte
+            mIk = parseTag(index, data);
+            if (mIk == null) {
                 Log.d(TAG, "Invalid data! can't parse IK!");
                 return;
             }
 
-            valid = true;
+            mValid = true;
         } catch (IllegalArgumentException illegalArgumentException) {
             Log.e(TAG, "Invalid base-64 content");
         }
@@ -129,23 +129,31 @@ class EapAkaSecurityContext {
         return dest;
     }
 
-    /** Returns {@code valid}. */
+    /**
+     * Returns {@code valid}.
+     */
     boolean isValid() {
-        return valid;
+        return mValid;
     }
 
-    /** Returns {@code res}. */
+    /**
+     * Returns {@code res}.
+     */
     public byte[] getRes() {
-        return res;
+        return mRes;
     }
 
-    /** Returns {@code ck}. */
+    /**
+     * Returns {@code ck}.
+     */
     public byte[] getCk() {
-        return ck;
+        return mCk;
     }
 
-    /** Returns {@code ik}. */
+    /**
+     * Returns {@code ik}.
+     */
     public byte[] getIk() {
-        return ik;
+        return mIk;
     }
 }
diff --git a/java/com/android/libraries/entitlement/eapaka/MasterKey.java b/java/com/android/libraries/entitlement/eapaka/MasterKey.java
index 57b8ab3..d37894d 100644
--- a/java/com/android/libraries/entitlement/eapaka/MasterKey.java
+++ b/java/com/android/libraries/entitlement/eapaka/MasterKey.java
@@ -21,6 +21,8 @@ import static java.nio.charset.StandardCharsets.UTF_8;
 import android.text.TextUtils;
 import android.util.Log;
 
+import androidx.annotation.Nullable;
+
 import com.android.libraries.entitlement.ServiceEntitlementException;
 import com.android.libraries.entitlement.eapaka.utils.BytesConverter;
 
@@ -28,8 +30,6 @@ import java.math.BigInteger;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 
-import androidx.annotation.Nullable;
-
 /**
  * The class for Master Key.
  *
@@ -49,13 +49,13 @@ class MasterKey {
     private static final int LENGTH_TEKS = 160;
 
     /* Master Key */
-    private byte[] masterKey;
+    private byte[] mMasterKey;
 
     /* Transient EAP Keys */
-    private byte[] encr;
-    private byte[] aut;
-    private byte[] msk;
-    private byte[] emsk;
+    private byte[] mEncr;
+    private byte[] mAut;
+    private byte[] mMsk;
+    private byte[] mEmsk;
 
     private MasterKey() {
     }
@@ -91,7 +91,7 @@ class MasterKey {
         try {
             MessageDigest messageDigest = MessageDigest.getInstance("SHA-1");
             messageDigest.update(data);
-            masterKey = messageDigest.digest();
+            mMasterKey = messageDigest.digest();
         } catch (NoSuchAlgorithmException e) {
             Log.d(TAG, "process SHA-1 failed", e);
         }
@@ -118,29 +118,29 @@ class MasterKey {
         }
 
         int index = 0;
-        encr = new byte[LENGTH_K_ENCR];
-        System.arraycopy(teks, index, encr, 0, LENGTH_K_ENCR);
+        mEncr = new byte[LENGTH_K_ENCR];
+        System.arraycopy(teks, index, mEncr, 0, LENGTH_K_ENCR);
         index += LENGTH_K_ENCR;
-        aut = new byte[LENGTH_K_AUT];
-        System.arraycopy(teks, index, aut, 0, LENGTH_K_AUT);
+        mAut = new byte[LENGTH_K_AUT];
+        System.arraycopy(teks, index, mAut, 0, LENGTH_K_AUT);
         index += LENGTH_K_AUT;
-        msk = new byte[LENGTH_MSK];
-        System.arraycopy(teks, index, msk, 0, LENGTH_MSK);
+        mMsk = new byte[LENGTH_MSK];
+        System.arraycopy(teks, index, mMsk, 0, LENGTH_MSK);
         index += LENGTH_MSK;
-        emsk = new byte[LENGTH_EMSK];
-        System.arraycopy(teks, index, emsk, 0, LENGTH_EMSK);
+        mEmsk = new byte[LENGTH_EMSK];
+        System.arraycopy(teks, index, mEmsk, 0, LENGTH_EMSK);
     }
 
     /** Returns {@code aut}. */
     public byte[] getAut() {
-        return aut;
+        return mAut;
     }
 
     // RFC 4187 Appendix A.  Pseudo-Random Number Generator
     @Nullable
     private byte[] generatePsudoRandomNumber() {
         // Step 1: Choose a new, secret value for the seed-key, XKEY
-        byte[] key = masterKey;
+        byte[] key = mMasterKey;
 
         // 160-bit XKEY and XVAL values are used, so b = 160.  On each full
         // authentication, the Master Key is used as the initial secret seed-key
diff --git a/java/com/android/libraries/entitlement/http/HttpClient.java b/java/com/android/libraries/entitlement/http/HttpClient.java
index 79f42ff..9d102ce 100644
--- a/java/com/android/libraries/entitlement/http/HttpClient.java
+++ b/java/com/android/libraries/entitlement/http/HttpClient.java
@@ -26,6 +26,8 @@ import static java.util.concurrent.TimeUnit.SECONDS;
 import android.text.TextUtils;
 import android.util.Log;
 
+import androidx.annotation.WorkerThread;
+
 import com.android.libraries.entitlement.ServiceEntitlementException;
 import com.android.libraries.entitlement.http.HttpConstants.ContentType;
 import com.android.libraries.entitlement.utils.StreamUtils;
@@ -39,9 +41,9 @@ import java.net.URL;
 import java.net.URLConnection;
 import java.util.Map;
 
-import androidx.annotation.WorkerThread;
-
-/** Implement the HTTP request method according to TS.43 specification. */
+/**
+ * Implement the HTTP request method according to TS.43 specification.
+ */
 public class HttpClient {
     private static final String TAG = "ServiceEntitlement";
     private static final boolean DEBUG = false; // STOPSHIP if true
@@ -49,7 +51,7 @@ public class HttpClient {
     private static final int SOCKET_TIMEOUT_VALUE = (int) SECONDS.toMillis(30);
     private static final int CONNECT_TIMEOUT_VALUE = (int) SECONDS.toMillis(30);
 
-    private HttpURLConnection connection;
+    private HttpURLConnection mConnection;
 
     @WorkerThread
     // TODO(b/177544547): Add debug messages
@@ -57,23 +59,23 @@ public class HttpClient {
         try {
             logd("HttpClient.request url: " + request.url());
             createConnection(request);
-            if (connection == null) {
+            if (mConnection == null) {
                 logd("HttpClient.request connection is null");
                 throw new ServiceEntitlementException("No connection");
             }
-            logd("HttpClient.request headers (partial): " + connection.getRequestProperties());
+            logd("HttpClient.request headers (partial): " + mConnection.getRequestProperties());
             if (POST.equals(request.requestMethod())) {
-                try (OutputStream out = new DataOutputStream(connection.getOutputStream())) {
+                try (OutputStream out = new DataOutputStream(mConnection.getOutputStream())) {
                     out.write(request.postData().toString().getBytes(UTF_8));
                     logd("HttpClient.request post data: " + request.postData());
                 }
             }
-            connection.connect(); // This is to trigger SocketTimeoutException early
-            HttpResponse response = getHttpResponse(connection);
+            mConnection.connect(); // This is to trigger SocketTimeoutException early
+            HttpResponse response = getHttpResponse(mConnection);
             Log.d(TAG, "HttpClient.response : " + response);
             return response;
         } catch (IOException e) {
-            InputStream errorStream = connection.getErrorStream();
+            InputStream errorStream = mConnection.getErrorStream();
             Log.e(
                     TAG,
                     "HttpClient.request() error: " + StreamUtils.inputStreamToStringSafe(
@@ -87,19 +89,19 @@ public class HttpClient {
     private void createConnection(HttpRequest request) throws ServiceEntitlementException {
         try {
             URL url = new URL(request.url());
-            connection = (HttpURLConnection) url.openConnection();
+            mConnection = (HttpURLConnection) url.openConnection();
 
             // add HTTP headers
             for (Map.Entry<String, String> entry : request.requestProperties().entrySet()) {
-                connection.addRequestProperty(entry.getKey(), entry.getValue());
+                mConnection.addRequestProperty(entry.getKey(), entry.getValue());
             }
 
             // set parameters
-            connection.setRequestMethod(request.requestMethod());
-            connection.setConnectTimeout(CONNECT_TIMEOUT_VALUE);
-            connection.setReadTimeout(SOCKET_TIMEOUT_VALUE);
+            mConnection.setRequestMethod(request.requestMethod());
+            mConnection.setConnectTimeout(CONNECT_TIMEOUT_VALUE);
+            mConnection.setReadTimeout(SOCKET_TIMEOUT_VALUE);
             if (POST.equals(request.requestMethod())) {
-                connection.setDoOutput(true);
+                mConnection.setDoOutput(true);
             }
         } catch (IOException e) {
             Log.e(TAG, "IOException: " + e.getMessage());
@@ -108,9 +110,9 @@ public class HttpClient {
     }
 
     private void closeConnection() {
-        if (connection != null) {
-            connection.disconnect();
-            connection = null;
+        if (mConnection != null) {
+            mConnection.disconnect();
+            mConnection = null;
         }
     }
 
@@ -121,8 +123,9 @@ public class HttpClient {
             logd("HttpClient.response headers: " + connection.getHeaderFields());
             if (responseCode != HttpURLConnection.HTTP_OK) {
                 throw new ServiceEntitlementException(
-                  ServiceEntitlementException.ERROR_HTTP_STATUS_NOT_SUCCESS, responseCode, null,
-                  "Invalid connection response", null);
+                        ServiceEntitlementException.ERROR_HTTP_STATUS_NOT_SUCCESS, responseCode,
+                        null,
+                        "Invalid connection response", null);
             }
             String responseBody = readResponse(connection);
             logd("HttpClient.response body: " + responseBody);
@@ -134,8 +137,8 @@ public class HttpClient {
                     .build();
         } catch (IOException e) {
             throw new ServiceEntitlementException(
-              ServiceEntitlementException.ERROR_HTTP_STATUS_NOT_SUCCESS, 0,  null,
-              "Read response failed!", e);
+                    ServiceEntitlementException.ERROR_HTTP_STATUS_NOT_SUCCESS, 0, null,
+                    "Read response failed!", e);
         }
     }
 
diff --git a/java/com/android/libraries/entitlement/http/HttpConstants.java b/java/com/android/libraries/entitlement/http/HttpConstants.java
index c4ed5e2..58f8c48 100644
--- a/java/com/android/libraries/entitlement/http/HttpConstants.java
+++ b/java/com/android/libraries/entitlement/http/HttpConstants.java
@@ -16,21 +16,30 @@
 
 package com.android.libraries.entitlement.http;
 
-/** Http constants using for entitlement flow of TS.43. */
+/**
+ * Http constants using for entitlement flow of TS.43.
+ */
 public final class HttpConstants {
-    private HttpConstants() {}
+    private HttpConstants() {
+    }
 
-    /** Possible request methods for Entitlement server response. */
+    /**
+     * Possible request methods for Entitlement server response.
+     */
     public static final class RequestMethod {
-        private RequestMethod() {}
+        private RequestMethod() {
+        }
 
         public static final String GET = "GET";
         public static final String POST = "POST";
     }
 
-    /** Possible content type for Entitlement server response. */
+    /**
+     * Possible content type for Entitlement server response.
+     */
     public static final class ContentType {
-        private ContentType() {}
+        private ContentType() {
+        }
 
         public static final int UNKNOWN = -1;
         public static final int JSON = 0;
diff --git a/java/com/android/libraries/entitlement/http/HttpRequest.java b/java/com/android/libraries/entitlement/http/HttpRequest.java
index af81b10..733355f 100644
--- a/java/com/android/libraries/entitlement/http/HttpRequest.java
+++ b/java/com/android/libraries/entitlement/http/HttpRequest.java
@@ -21,14 +21,15 @@ import android.util.ArrayMap;
 import com.google.auto.value.AutoValue;
 import com.google.common.collect.ImmutableMap;
 
-import java.util.Map;
-
 import org.json.JSONObject;
 
-/** The parameters of the http request. */
+import java.util.Map;
+
+/**
+ * The parameters of the http request.
+ */
 @AutoValue
 public abstract class HttpRequest {
-
     public abstract String url();
 
     public abstract String requestMethod();
@@ -39,7 +40,9 @@ public abstract class HttpRequest {
 
     public abstract ImmutableMap<String, String> requestProperties();
 
-    /** Builder of {@link HttpRequest}. */
+    /**
+     * Builder of {@link HttpRequest}.
+     */
     @AutoValue.Builder
     public abstract static class Builder {
 
diff --git a/java/com/android/libraries/entitlement/http/HttpResponse.java b/java/com/android/libraries/entitlement/http/HttpResponse.java
index 1cb165e..b6ca35f 100644
--- a/java/com/android/libraries/entitlement/http/HttpResponse.java
+++ b/java/com/android/libraries/entitlement/http/HttpResponse.java
@@ -20,11 +20,14 @@ import com.android.libraries.entitlement.http.HttpConstants.ContentType;
 
 import com.google.auto.value.AutoValue;
 
-/** The response of the http request. */
+/**
+ * The response of the http request.
+ */
 @AutoValue
 public abstract class HttpResponse {
-
-    /** Content type of the response. */
+    /**
+     * Content type of the response.
+     */
     public abstract int contentType();
 
     public abstract String body();
@@ -33,7 +36,9 @@ public abstract class HttpResponse {
 
     public abstract String responseMessage();
 
-    /** Builder of {@link HttpResponse}. */
+    /**
+     * Builder of {@link HttpResponse}.
+     */
     @AutoValue.Builder
     public abstract static class Builder {
 
diff --git a/java/com/android/libraries/entitlement/utils/BytesConverter.java b/java/com/android/libraries/entitlement/utils/BytesConverter.java
index 034ac9c..3ec1df2 100644
--- a/java/com/android/libraries/entitlement/utils/BytesConverter.java
+++ b/java/com/android/libraries/entitlement/utils/BytesConverter.java
@@ -16,10 +16,10 @@
 
 package com.android.libraries.entitlement.eapaka.utils;
 
-import java.nio.ByteBuffer;
-
 import androidx.annotation.Nullable;
 
+import java.nio.ByteBuffer;
+
 public class BytesConverter {
     private static final int INTEGER_SIZE = 4; // 4 bytes
 
@@ -53,7 +53,9 @@ public class BytesConverter {
         return ret.toString();
     }
 
-    /** Converts integer to 4 bytes. */
+    /**
+     * Converts integer to 4 bytes.
+     */
     public static byte[] convertIntegerTo4Bytes(int value) {
         return ByteBuffer.allocate(INTEGER_SIZE).putInt(value).array();
     }
diff --git a/java/com/android/libraries/entitlement/utils/StreamUtils.java b/java/com/android/libraries/entitlement/utils/StreamUtils.java
index 1ff2ffc..e2ba890 100644
--- a/java/com/android/libraries/entitlement/utils/StreamUtils.java
+++ b/java/com/android/libraries/entitlement/utils/StreamUtils.java
@@ -22,15 +22,18 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
 
-/** Utility methods about InputStream. */
+/**
+ * Utility methods about InputStream.
+ */
 public final class StreamUtils {
-
     private static final int BUFFER_SIZE = 1024;
 
     private StreamUtils() {
     }
 
-    /** Reads an {@link InputStream} into a string. */
+    /**
+     * Reads an {@link InputStream} into a string.
+     */
     public static String inputStreamToString(InputStream inputStream) throws IOException {
         try (BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream);
              ByteArrayOutputStream result = new ByteArrayOutputStream()) {
@@ -43,7 +46,9 @@ public final class StreamUtils {
         }
     }
 
-    /** Reads an {@link InputStream} into a string. Returns an empty string if any error. */
+    /**
+     * Reads an {@link InputStream} into a string. Returns an empty string if any error.
+     */
     public static String inputStreamToStringSafe(InputStream inputStream) {
         try {
             return inputStreamToString(inputStream);