Improve functionality of UI interceptor

components/application-mgt/org.wso2.carbon.device.application.mgt.api/src/main/java/org/wso2/carbon/device/application/mgt/api/services/impl/ConfigRetrieveAPIImpl.java

@@ -21,7 +21,6 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.wso2.carbon.device.application.mgt.api.services.ConfigRetrieveAPI;
 import org.wso2.carbon.device.application.mgt.common.config.UIConfiguration;
-import org.wso2.carbon.device.application.mgt.common.exception.LifecycleManagementException;
 import org.wso2.carbon.device.application.mgt.common.services.AppmDataHandler;
 import org.wso2.carbon.device.application.mgt.core.util.APIUtil;
 

components/application-mgt/org.wso2.carbon.device.application.mgt.common/src/main/java/org/wso2/carbon/device/application/mgt/common/ProxyResponse.java

@@ -20,7 +20,6 @@ package org.wso2.carbon.device.application.mgt.common;
 public class ProxyResponse {
 
     private int code;
-    private String url;
     private String data;
     private String executorResponse;
 
@@ -28,10 +27,6 @@ public class ProxyResponse {
 
     public void setCode(int code) { this.code = code; }
 
-    public String getUrl() { return url; }
-
-    public void setUrl(String url) { this.url = url; }
-
     public String getData() { return data; }
 
     public void setData(String data) { this.data = data; }

components/ui-request-interceptor/io.entgra.ui.request.interceptor/src/main/java/io/entgra/ui/request/interceptor/InvokerHandler.java

@@ -55,6 +55,7 @@ import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.http.HttpSession;
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.Enumeration;
 import java.util.List;
 
@@ -91,10 +92,10 @@ public class InvokerHandler extends HttpServlet {
                 }
                 if (proxyResponse.getExecutorResponse().contains(HandlerConstants.EXECUTOR_EXCEPTION_PREFIX)) {
                     log.error("Error occurred while invoking the API endpoint.");
-                    HandlerUtil.handleError(req, resp, serverUrl, platform, proxyResponse);
+                    HandlerUtil.handleError(resp, proxyResponse);
                     return;
                 }
-                HandlerUtil.handleSuccess(req, resp, serverUrl, platform, proxyResponse);
+                HandlerUtil.handleSuccess(resp, proxyResponse);
             }
         } catch (FileUploadException e) {
             log.error("Error occurred when processing Multipart POST request.", e);
@@ -119,10 +120,10 @@ public class InvokerHandler extends HttpServlet {
                 }
                 if (proxyResponse.getExecutorResponse().contains(HandlerConstants.EXECUTOR_EXCEPTION_PREFIX)) {
                     log.error("Error occurred while invoking the API endpoint.");
-                    HandlerUtil.handleError(req, resp, serverUrl, platform, proxyResponse);
+                    HandlerUtil.handleError(resp, proxyResponse);
                     return;
                 }
-                HandlerUtil.handleSuccess(req, resp, serverUrl, platform, proxyResponse);
+                HandlerUtil.handleSuccess(resp, proxyResponse);
             }
         } catch (IOException e) {
             log.error("Error occurred when processing GET request.", e);
@@ -146,10 +147,10 @@ public class InvokerHandler extends HttpServlet {
                 }
                 if (proxyResponse.getExecutorResponse().contains(HandlerConstants.EXECUTOR_EXCEPTION_PREFIX)) {
                     log.error("Error occurred while invoking the API endpoint.");
-                    HandlerUtil.handleError(req, resp, serverUrl, platform, proxyResponse);
+                    HandlerUtil.handleError(resp, proxyResponse);
                     return;
                 }
-                HandlerUtil.handleSuccess(req, resp, serverUrl, platform, proxyResponse);
+                HandlerUtil.handleSuccess(resp, proxyResponse);
             }
         } catch (FileUploadException e) {
             log.error("Error occurred when processing Multipart PUT request.", e);
@@ -174,10 +175,10 @@ public class InvokerHandler extends HttpServlet {
                 }
                 if (proxyResponse.getExecutorResponse().contains(HandlerConstants.EXECUTOR_EXCEPTION_PREFIX)) {
                     log.error("Error occurred while invoking the API endpoint.");
-                    HandlerUtil.handleError(req, resp, serverUrl, platform, proxyResponse);
+                    HandlerUtil.handleError(resp, proxyResponse);
                     return;
                 }
-                HandlerUtil.handleSuccess(req, resp, serverUrl, platform, proxyResponse);
+                HandlerUtil.handleSuccess(resp, proxyResponse);
             }
         } catch (IOException e) {
             log.error("Error occurred when processing DELETE request.", e);
@@ -228,7 +229,13 @@ public class InvokerHandler extends HttpServlet {
      */
     private String generateBackendRequestURL(HttpServletRequest req) {
         StringBuilder urlBuilder = new StringBuilder();
-        urlBuilder.append(serverUrl).append(HandlerConstants.API_COMMON_CONTEXT).append(req.getPathInfo());
+        String endpointUrl = Arrays.stream(HandlerConstants.SKIPPING_API_CONTEXT)
+                .anyMatch(contextPath -> contextPath.contains(req.getPathInfo())) ?
+                serverUrl :
+                req.getScheme() + HandlerConstants.SCHEME_SEPARATOR + System.getProperty("iot.gateway.host")
+                        + HandlerConstants.COLON + HandlerUtil.getGatewayPort(req.getScheme());
+
+        urlBuilder.append(endpointUrl).append(HandlerConstants.API_COMMON_CONTEXT).append(req.getPathInfo());
         if (StringUtils.isNotEmpty(req.getQueryString())) {
             urlBuilder.append("?").append(req.getQueryString());
         }
@@ -275,7 +282,7 @@ public class InvokerHandler extends HttpServlet {
 
         if (session == null) {
             log.error("Unauthorized, You are not logged in. Please log in to the portal");
-            handleError(req, resp, HttpStatus.SC_UNAUTHORIZED);
+            handleError(resp, HttpStatus.SC_UNAUTHORIZED);
             return false;
         }
 
@@ -283,13 +290,13 @@ public class InvokerHandler extends HttpServlet {
         platform = (String) session.getAttribute(HandlerConstants.PLATFORM);
         if (authData == null) {
             log.error("Unauthorized, Access token not found in the current session");
-            handleError(req, resp, HttpStatus.SC_UNAUTHORIZED);
+            handleError(resp, HttpStatus.SC_UNAUTHORIZED);
             return false;
         }
 
         if (req.getMethod() == null) {
             log.error("Bad Request, Request method is empty");
-            handleError(req, resp, HttpStatus.SC_BAD_REQUEST);
+            handleError(resp, HttpStatus.SC_BAD_REQUEST);
             return false;
         }
         return true;
@@ -311,7 +318,7 @@ public class InvokerHandler extends HttpServlet {
             ProxyResponse proxyResponse = HandlerUtil.execute(httpRequest);
             if (proxyResponse.getExecutorResponse().contains(HandlerConstants.EXECUTOR_EXCEPTION_PREFIX)) {
                 log.error("Error occurred while invoking the API after refreshing the token.");
-                HandlerUtil.handleError(req, resp, serverUrl, platform, proxyResponse);
+                HandlerUtil.handleError(resp, proxyResponse);
                 return null;
             }
             return proxyResponse;
@@ -337,7 +344,7 @@ public class InvokerHandler extends HttpServlet {
         HttpSession session = req.getSession(false);
         if (session == null) {
             log.error("Couldn't find a session, hence it is required to login and proceed.");
-            handleError(req, resp, HttpStatus.SC_UNAUTHORIZED);
+            handleError(resp, HttpStatus.SC_UNAUTHORIZED);
             return false;
         }
 
@@ -354,7 +361,7 @@ public class InvokerHandler extends HttpServlet {
         ProxyResponse tokenResultResponse = HandlerUtil.execute(tokenEndpoint);
         if (tokenResultResponse.getExecutorResponse().contains(HandlerConstants.EXECUTOR_EXCEPTION_PREFIX)) {
             log.error("Error occurred while refreshing access token.");
-            HandlerUtil.handleError(req, resp, serverUrl, platform, tokenResultResponse);
+            HandlerUtil.handleError(resp, tokenResultResponse);
             return false;
         }
 
@@ -378,24 +385,23 @@ public class InvokerHandler extends HttpServlet {
         }
 
         log.error("Error Occurred in token renewal process.");
-        handleError(req, resp, HttpStatus.SC_INTERNAL_SERVER_ERROR);
+        handleError(resp, HttpStatus.SC_INTERNAL_SERVER_ERROR);
         return false;
     }
 
     /**
      * Handle error requests
      *
-     * @param req {@link HttpServletRequest}
      * @param resp {@link HttpServletResponse}
      * @param errorCode HTTP error status code
      * @throws IOException If error occurred when trying to send the error response.
      */
-    private static void handleError(HttpServletRequest req, HttpServletResponse resp, int errorCode)
+    private static void handleError(HttpServletResponse resp, int errorCode)
             throws IOException {
         ProxyResponse proxyResponse = new ProxyResponse();
         proxyResponse.setCode(errorCode);
         proxyResponse.setExecutorResponse(
                 HandlerConstants.EXECUTOR_EXCEPTION_PREFIX + HandlerUtil.getStatusKey(errorCode));
-        HandlerUtil.handleError(req, resp, serverUrl, platform, proxyResponse);
+        HandlerUtil.handleError(resp, proxyResponse);
     }
 }

components/ui-request-interceptor/io.entgra.ui.request.interceptor/src/main/java/io/entgra/ui/request/interceptor/LoginHandler.java

@@ -56,14 +56,13 @@ public class LoginHandler extends HttpServlet {
 
     private static String username;
     private static String password;
-    private static String platform;
+    private static String gatewayUrl;
-    private static String serverUrl;
     private static String uiConfigUrl;
 
     @Override
     protected void doPost(HttpServletRequest req, HttpServletResponse resp) {
         try {
-            validateLoginRequest(req, resp);
+            validateLoginRequest(req);
             HttpSession httpSession = req.getSession(false);
             if (httpSession != null) {
                 httpSession.invalidate();
@@ -79,14 +78,14 @@ public class LoginHandler extends HttpServlet {
             if (!StringUtils.isEmpty(executorResponse) && executorResponse
                     .contains(HandlerConstants.EXECUTOR_EXCEPTION_PREFIX)) {
                 log.error("Error occurred while getting UI configurations by invoking " + uiConfigUrl);
-                HandlerUtil.handleError(req, resp, serverUrl, platform, uiConfigResponse);
+                HandlerUtil.handleError(resp, uiConfigResponse);
                 return;
             }
 
             String uiConfig = uiConfigResponse.getData();
             if (uiConfig == null){
                 log.error("UI config retrieval is failed, and didn't find UI configuration for App manager.");
-                HandlerUtil.handleError(req, resp, serverUrl, platform, null);
+                HandlerUtil.handleError(resp, null);
                 return;
             }
             JsonElement uiConfigJsonElement = jsonParser.parse(uiConfigResponse.getData());
@@ -94,12 +93,12 @@ public class LoginHandler extends HttpServlet {
             if (uiConfigJsonElement.isJsonObject()) {
                 uiConfigJsonObject = uiConfigJsonElement.getAsJsonObject();
                 httpSession.setAttribute(HandlerConstants.UI_CONFIG_KEY, uiConfigJsonObject);
-                httpSession.setAttribute(HandlerConstants.PLATFORM, serverUrl);
+                httpSession.setAttribute(HandlerConstants.PLATFORM, gatewayUrl);
             }
             if (uiConfigJsonObject == null) {
                 log.error(
                         "Either UI config json element is not an json object or converting rom json element to json object is failed.");
-                HandlerUtil.handleError(req, resp, serverUrl, platform, null);
+                HandlerUtil.handleError(resp, null);
                 return;
             }
 
@@ -111,7 +110,7 @@ public class LoginHandler extends HttpServlet {
                 log.debug("SSO is enabled");
             } else {
                 // default login
-                HttpPost apiRegEndpoint = new HttpPost(serverUrl + HandlerConstants.APP_REG_ENDPOINT);
+                HttpPost apiRegEndpoint = new HttpPost(gatewayUrl + HandlerConstants.APP_REG_ENDPOINT);
                 apiRegEndpoint.setHeader(HttpHeaders.AUTHORIZATION, HandlerConstants.BASIC + Base64.getEncoder()
                         .encodeToString((username + HandlerConstants.COLON + password).getBytes()));
                 apiRegEndpoint.setHeader(HTTP.CONTENT_TYPE, ContentType.APPLICATION_JSON.toString());
@@ -120,18 +119,17 @@ public class LoginHandler extends HttpServlet {
                 ProxyResponse clientAppResponse = HandlerUtil.execute(apiRegEndpoint);
 
                 if (clientAppResponse.getCode() == HttpStatus.SC_UNAUTHORIZED){
-                    HandlerUtil.handleError(req, resp, serverUrl, platform, clientAppResponse);
+                    HandlerUtil.handleError(resp, clientAppResponse);
                     return;
                 }
                 if (clientAppResponse.getCode() == HttpStatus.SC_CREATED && getTokenAndPersistInSession(req, resp,
                         clientAppResponse.getData(), scopes)) {
                     ProxyResponse proxyResponse = new ProxyResponse();
                     proxyResponse.setCode(HttpStatus.SC_OK);
-                    proxyResponse.setUrl(serverUrl + HandlerConstants.PATH_SEPARATOR + platform);
+                    HandlerUtil.handleSuccess(resp, proxyResponse);
-                    HandlerUtil.handleSuccess(req, resp, serverUrl, platform, proxyResponse);
                     return;
                 }
-                HandlerUtil.handleError(req, resp, serverUrl, platform, null);
+                HandlerUtil.handleError(resp, null);
             }
         } catch (IOException e) {
             log.error("Error occurred while sending the response into the socket. ", e);
@@ -165,13 +163,13 @@ public class LoginHandler extends HttpServlet {
 
                 if (tokenResultResponse.getExecutorResponse().contains(HandlerConstants.EXECUTOR_EXCEPTION_PREFIX)) {
                     log.error("Error occurred while invoking the API to get token data.");
-                    HandlerUtil.handleError(req, resp, serverUrl, platform, tokenResultResponse);
+                    HandlerUtil.handleError(resp, tokenResultResponse);
                     return false;
                 }
                 String tokenResult = tokenResultResponse.getData();
                 if (tokenResult == null){
                     log.error("Invalid token response is received.");
-                    HandlerUtil.handleError(req, resp, serverUrl, platform, tokenResultResponse);
+                    HandlerUtil.handleError(resp, tokenResultResponse);
                     return false;
                 }
 
@@ -222,28 +220,21 @@ public class LoginHandler extends HttpServlet {
      * @param req - {@link HttpServletRequest}
      * Define username and password static parameters.
      */
-    private static void validateLoginRequest(HttpServletRequest req, HttpServletResponse resp) throws LoginException {
+    private static void validateLoginRequest(HttpServletRequest req) throws LoginException {
+        String gatewayCarbonPort = System.getProperty("iot.gateway.carbon.https.port");
+        if (HandlerConstants.HTTP_PROTOCOL.equals(req.getScheme())){
+            gatewayCarbonPort = System.getProperty("iot.gateway.carbon.http.port");
+        }
         username = req.getParameter("username");
         password = req.getParameter("password");
-        platform = req.getParameter(HandlerConstants.PLATFORM);
+        gatewayUrl = req.getScheme() + HandlerConstants.SCHEME_SEPARATOR + System.getProperty("iot.gateway.host")
-        serverUrl = req.getScheme() + HandlerConstants.SCHEME_SEPARATOR + req.getServerName() + HandlerConstants.COLON
+                + HandlerConstants.COLON + HandlerUtil.getGatewayPort(req.getScheme());
-                    + System.getProperty("iot.gateway.https.port");
         uiConfigUrl = req.getScheme() + HandlerConstants.SCHEME_SEPARATOR + req.getServerName() + HandlerConstants.COLON
-                + System.getProperty("iot.gateway.carbon.https.port") + HandlerConstants.UI_CONFIG_ENDPOINT;
+                + gatewayCarbonPort + HandlerConstants.UI_CONFIG_ENDPOINT;
-
-        try {
-            if (platform == null) {
-                resp.sendRedirect(serverUrl + HandlerConstants.DEFAULT_ERROR_CALLBACK);
-                throw new LoginException("Invalid login request. Platform parameter is Null.");
-            }
         if (username == null || password == null) {
-                resp.sendRedirect(serverUrl + HandlerConstants.PATH_SEPARATOR + platform
+            String msg = "Invalid login request. Username or Password is not received for login request.";
-                        + HandlerConstants.DEFAULT_ERROR_CALLBACK);
+            log.error(msg);
-                throw new LoginException(
+            throw new LoginException(msg);
-                        " Invalid login request. Username or Password is not received for login request.");
-            }
-        } catch (IOException e) {
-            throw new LoginException("Error occurred while redirecting to default error page.", e);
         }
     }
 
@@ -271,8 +262,7 @@ public class LoginHandler extends HttpServlet {
      * @throws IOException IO exception throws if an error occurred when invoking token endpoint
      */
     private ProxyResponse getTokenResult(String encodedClientApp, JsonArray scopes) throws IOException {
-
+        HttpPost tokenEndpoint = new HttpPost(gatewayUrl + HandlerConstants.TOKEN_ENDPOINT);
-        HttpPost tokenEndpoint = new HttpPost(serverUrl + HandlerConstants.TOKEN_ENDPOINT);
         tokenEndpoint.setHeader(HttpHeaders.AUTHORIZATION, HandlerConstants.BASIC + encodedClientApp);
         tokenEndpoint.setHeader(HttpHeaders.CONTENT_TYPE, ContentType.APPLICATION_FORM_URLENCODED.toString());
         String scopeString = getScopeString(scopes);

components/ui-request-interceptor/io.entgra.ui.request.interceptor/src/main/java/io/entgra/ui/request/interceptor/LogoutHandler.java

@@ -38,9 +38,6 @@ public class LogoutHandler extends HttpServlet {
 
     @Override
     protected void doPost(HttpServletRequest req, HttpServletResponse resp) {
-        String serverUrl = req.getScheme() + HandlerConstants.SCHEME_SEPARATOR + req.getServerName()
-                + HandlerConstants.COLON + req.getServerPort();
-        String platform = req.getParameter(HandlerConstants.PLATFORM);
         HttpSession httpSession = req.getSession(false);
         if (httpSession != null) {
             httpSession.invalidate();
@@ -50,9 +47,8 @@ public class LogoutHandler extends HttpServlet {
 
         ProxyResponse proxyResponse = new ProxyResponse();
         proxyResponse.setCode(HttpStatus.SC_OK);
-        proxyResponse.setUrl(serverUrl + HandlerConstants.PATH_SEPARATOR + platform + HandlerConstants.LOGIN_PAGE);
         try {
-            HandlerUtil.handleSuccess(req, resp, serverUrl, platform, proxyResponse);
+            HandlerUtil.handleSuccess(resp, proxyResponse);
         } catch (IOException e) {
             log.error("Error occurred when processing logout request.", e);
         }

components/ui-request-interceptor/io.entgra.ui.request.interceptor/src/main/java/io/entgra/ui/request/interceptor/UserHandler.java

@@ -25,7 +25,6 @@ import com.google.gson.JsonSyntaxException;
 import io.entgra.ui.request.interceptor.beans.AuthData;
 import io.entgra.ui.request.interceptor.util.HandlerConstants;
 import io.entgra.ui.request.interceptor.util.HandlerUtil;
-import org.apache.commons.lang.StringUtils;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.http.HttpHeaders;
@@ -52,24 +51,18 @@ public class UserHandler extends HttpServlet {
     @Override
     protected void doPost(HttpServletRequest req, HttpServletResponse resp) {
         try {
-            String platform = req.getParameter(HandlerConstants.PLATFORM);
             String serverUrl =
-                    req.getScheme() + HandlerConstants.SCHEME_SEPARATOR + req.getServerName() + HandlerConstants.COLON
+                    req.getScheme() + HandlerConstants.SCHEME_SEPARATOR + System.getProperty("iot.gateway.host")
-                            + System.getProperty("iot.gateway.https.port");
+                            + HandlerConstants.COLON + HandlerUtil.getGatewayPort(req.getScheme());
-            if (StringUtils.isBlank(platform)) {
-                sendUnAuthorizeResponse(req, resp, serverUrl, platform);
-                return;
-            }
-
             HttpSession httpSession = req.getSession(false);
             if (httpSession == null) {
-                sendUnAuthorizeResponse(req, resp, serverUrl, platform);
+                sendUnAuthorizeResponse(resp);
                 return;
             }
 
             AuthData authData = (AuthData) httpSession.getAttribute(HandlerConstants.SESSION_AUTH_DATA_KEY);
             if (authData == null) {
-                sendUnAuthorizeResponse(req, resp, serverUrl, platform);
+                sendUnAuthorizeResponse(resp);
                 return;
             }
 
@@ -84,13 +77,13 @@ public class UserHandler extends HttpServlet {
 
             if (tokenStatus.getExecutorResponse().contains(HandlerConstants.EXECUTOR_EXCEPTION_PREFIX)) {
                 log.error("Error occurred while invoking the API to get token status.");
-                HandlerUtil.handleError(req, resp, serverUrl, platform, tokenStatus);
+                HandlerUtil.handleError(resp, tokenStatus);
                 return;
             }
             String tokenData = tokenStatus.getData();
             if (tokenData == null) {
                 log.error("Invalid token data is received.");
-                HandlerUtil.handleError(req, resp, serverUrl, platform, tokenStatus);
+                HandlerUtil.handleError(resp, tokenStatus);
                 return;
             }
             JsonParser jsonParser = new JsonParser();
@@ -98,14 +91,14 @@ public class UserHandler extends HttpServlet {
             if (jTokenResult.isJsonObject()) {
                 JsonObject jTokenResultAsJsonObject = jTokenResult.getAsJsonObject();
                 if (!jTokenResultAsJsonObject.get("active").getAsBoolean()) {
-                    sendUnAuthorizeResponse(req, resp, serverUrl, platform);
+                    sendUnAuthorizeResponse(resp);
                     return;
                 }
                 ProxyResponse proxyResponse = new ProxyResponse();
                 proxyResponse.setCode(HttpStatus.SC_OK);
                 proxyResponse.setData(
                         jTokenResultAsJsonObject.get("username").getAsString().replaceAll("@carbon.super", ""));
-                HandlerUtil.handleSuccess(req, resp, serverUrl, platform, proxyResponse);
+                HandlerUtil.handleSuccess(resp, proxyResponse);
             }
         } catch (IOException e) {
             log.error("Error occurred while sending the response into the socket. ", e);
@@ -117,17 +110,14 @@ public class UserHandler extends HttpServlet {
     /**
      * Send UnAuthorized Response to the user
      * 
-     * @param req HttpServletRequest object
      * @param resp HttpServletResponse object
-     * @param serverUrl Url of the server
-     * @param platform Requested platform
      */
-    private void sendUnAuthorizeResponse(HttpServletRequest req, HttpServletResponse resp, String serverUrl, String platform)
+    private void sendUnAuthorizeResponse(HttpServletResponse resp)
             throws IOException {
         ProxyResponse proxyResponse = new ProxyResponse();
         proxyResponse.setCode(HttpStatus.SC_UNAUTHORIZED);
         proxyResponse.setExecutorResponse(
                 HandlerConstants.EXECUTOR_EXCEPTION_PREFIX + HandlerUtil.getStatusKey(HttpStatus.SC_UNAUTHORIZED));
-        HandlerUtil.handleError(req, resp, serverUrl, platform, proxyResponse);
+        HandlerUtil.handleError(resp, proxyResponse);
     }
 }

components/ui-request-interceptor/io.entgra.ui.request.interceptor/src/main/java/io/entgra/ui/request/interceptor/util/HandlerConstants.java

@@ -34,15 +34,15 @@ public class HandlerConstants {
     public static final String PLATFORM = "platform";
     public static final String USERNAME = "username";
     public static final String PASSWORD = "password";
-    public static final String DEFAULT_ERROR_CALLBACK = "/pages/error/default";
-    public static final String ERROR_CALLBACK_KEY = "errorCallback";
     public static final String API_COMMON_CONTEXT = "/api";
     public static final String EXECUTOR_EXCEPTION_PREFIX = "ExecutorException-";
     public static final String TOKEN_IS_EXPIRED = "ACCESS_TOKEN_IS_EXPIRED";
 
     public static final String SCHEME_SEPARATOR = "://";
     public static final String COLON = ":";
-    public static final String PATH_SEPARATOR = "/";
+    public static final String HTTP_PROTOCOL = "http";
+
+    public static final String[] SKIPPING_API_CONTEXT = {"artifact", "conf"};
 
     public static final int INTERNAL_ERROR_CODE = 500;
     public static final long TIMEOUT = 1200;

components/ui-request-interceptor/io.entgra.ui.request.interceptor/src/main/java/io/entgra/ui/request/interceptor/util/HandlerUtil.java

@@ -58,6 +58,8 @@ public class HandlerUtil {
             ProxyResponse proxyResponse = new ProxyResponse();
 
             if (response == null) {
+                log.error("Received null response for http request : " + httpRequest.getMethod() + " " + httpRequest
+                        .getURI().toString());
                 proxyResponse.setCode(HandlerConstants.INTERNAL_ERROR_CODE);
                 proxyResponse.setExecutorResponse(HandlerConstants.EXECUTOR_EXCEPTION_PREFIX + getStatusKey(
                         HandlerConstants.INTERNAL_ERROR_CODE));
@@ -84,6 +86,9 @@ public class HandlerUtil {
                             proxyResponse.setExecutorResponse(HandlerConstants.TOKEN_IS_EXPIRED);
                             return proxyResponse;
                         } else {
+                            log.error(
+                                    "Received " + statusCode + " response for http request : " + httpRequest.getMethod()
+                                            + " " + httpRequest.getURI().toString() + ". Error message: " + jsonString);
                             proxyResponse.setCode(statusCode);
                             proxyResponse.setData(jsonString);
                             proxyResponse.setExecutorResponse(
@@ -91,6 +96,9 @@ public class HandlerUtil {
                             return proxyResponse;
                         }
                     }
+                    log.error("Received " + statusCode +
+                            " response for http request : " + httpRequest.getMethod() + " " + httpRequest.getURI()
+                            .toString() + ". Error message: " + jsonString);
                     proxyResponse.setCode(statusCode);
                     proxyResponse.setData(jsonString);
                     proxyResponse
@@ -147,10 +155,7 @@ public class HandlerUtil {
      * @param resp {@link HttpServletResponse}
      * Return Error Response.
      */
-    public static void handleError(HttpServletRequest req, HttpServletResponse resp, String serverUrl,
+    public static void handleError(HttpServletResponse resp, ProxyResponse proxyResponse) throws IOException {
-            String platform, ProxyResponse proxyResponse) throws IOException {
-
-        HttpSession httpSession = req.getSession(true);
         Gson gson = new Gson();
         if (proxyResponse == null){
             proxyResponse = new ProxyResponse();
@@ -158,27 +163,10 @@ public class HandlerUtil {
             proxyResponse.setExecutorResponse(HandlerConstants.EXECUTOR_EXCEPTION_PREFIX + HandlerUtil
                     .getStatusKey(HandlerConstants.INTERNAL_ERROR_CODE));
         }
-        if (platform == null){
-            platform = "default";
-        }
-
         resp.setStatus(proxyResponse.getCode());
         resp.setContentType(ContentType.APPLICATION_JSON.getMimeType());
         resp.setCharacterEncoding(Consts.UTF_8.name());
 
-        if (httpSession != null) {
-            JsonObject uiConfig = (JsonObject) httpSession.getAttribute(HandlerConstants.UI_CONFIG_KEY);
-            if (uiConfig == null){
-                proxyResponse.setUrl(serverUrl + "/" + platform + HandlerConstants.DEFAULT_ERROR_CALLBACK);
-            } else{
-                proxyResponse.setUrl(serverUrl + uiConfig.get(HandlerConstants.ERROR_CALLBACK_KEY).getAsJsonObject()
-                        .get(proxyResponse.getExecutorResponse().split(HandlerConstants.EXECUTOR_EXCEPTION_PREFIX)[1])
-                        .getAsString());
-            }
-        } else {
-            proxyResponse.setUrl(serverUrl + "/" + platform + HandlerConstants.DEFAULT_ERROR_CALLBACK);
-        }
-
         proxyResponse.setExecutorResponse(null);
         try (PrintWriter writer = resp.getWriter()) {
             writer.write(gson.toJson(proxyResponse));
@@ -190,24 +178,17 @@ public class HandlerUtil {
      * @param resp {@link HttpServletResponse}
      * Return Success Response.
      */
-    public static void handleSuccess(HttpServletRequest req, HttpServletResponse resp, String serverUrl,
+    public static void handleSuccess(HttpServletResponse resp, ProxyResponse proxyResponse) throws IOException {
-            String platform, ProxyResponse proxyResponse) throws IOException {
         if (proxyResponse == null){
-            handleError(req, resp, serverUrl, platform, null);
+            handleError(resp, null);
             return;
         }
-
         resp.setStatus(proxyResponse.getCode());
         resp.setContentType(ContentType.APPLICATION_JSON.getMimeType());
         resp.setCharacterEncoding(Consts.UTF_8.name());
-
         JSONObject response = new JSONObject();
-        String redirectUrl = proxyResponse.getUrl();
         String responseData = proxyResponse.getData();
 
-        if (!StringUtils.isEmpty(redirectUrl)){
-            response.put("url", redirectUrl);
-        }
         if (!StringUtils.isEmpty(responseData)){
             try {
                 JSONObject responseDataJsonObj = new JSONObject(responseData);
@@ -223,4 +204,17 @@ public class HandlerUtil {
         }
     }
 
+    /**
+     * Get gatway port according to request recieved scheme
+     * @param scheme https or https
+     * @return {@link String} gateway port
+     */
+    public static String getGatewayPort(String scheme) {
+        String gatewayPort = System.getProperty("iot.gateway.https.port");
+        if (HandlerConstants.HTTP_PROTOCOL.equals(scheme)) {
+            gatewayPort = System.getProperty("iot.gateway.http.port");
+        }
+        return gatewayPort;
+    }
+
 }