added external server name for GUI component

src/main/java/ch/ethz/seb/sebserver/gui/content/MonitoringClientConnection.java

@@ -307,7 +307,7 @@ public class MonitoringClientConnection implements TemplateComposer {
 
         final String webserviceServerAddress = this.pageService.getAuthorizationContextHolder()
                 .getWebserviceURIService()
-                .getWebserviceServerAddress();
+                .getExternalServerURL();
 
         final JavaScriptExecutor javaScriptExecutor = RWT.getClient().getService(JavaScriptExecutor.class);
         final String script = String.format(OPEN_SINGEL_ROOM_SCRIPT, roomName, webserviceServerAddress, roomName);

src/main/java/ch/ethz/seb/sebserver/gui/service/remote/webservice/auth/WebserviceURIService.java

@@ -14,6 +14,7 @@ import org.springframework.web.util.UriComponentsBuilder;
 
 import ch.ethz.seb.sebserver.gbl.api.API;
 import ch.ethz.seb.sebserver.gbl.profile.GuiProfile;
+import io.micrometer.core.instrument.util.StringUtils;
 
 @Component
 @GuiProfile
@@ -22,13 +23,15 @@ public class WebserviceURIService {
     private final String servletContextPath;
     private final String webserviceServerAddress;
     private final UriComponentsBuilder webserviceURIBuilder;
+    private final UriComponentsBuilder externaGUIURIBuilder;
 
     public WebserviceURIService(
             @Value("${sebserver.gui.webservice.protocol}") final String webserviceProtocol,
             @Value("${sebserver.gui.webservice.address}") final String webserviceServerAddress,
             @Value("${sebserver.gui.webservice.port}") final String webserviceServerPort,
             @Value("${server.servlet.context-path}") final String servletContextPath,
-            @Value("${sebserver.gui.webservice.apipath}") final String webserviceAPIPath) {
+            @Value("${sebserver.gui.webservice.apipath}") final String webserviceAPIPath,
+            @Value("${sebserver.gui.webservice.address.external}") final String externalServerName) {
 
         this.servletContextPath = servletContextPath;
         this.webserviceServerAddress =
@@ -38,6 +41,19 @@ public class WebserviceURIService {
                 .port(webserviceServerPort)
                 .path(servletContextPath)
                 .path(webserviceAPIPath);
+        if (StringUtils.isNotBlank(externalServerName)) {
+            this.externaGUIURIBuilder = UriComponentsBuilder
+                    .fromHttpUrl(webserviceProtocol + "://" + externalServerName)
+                    .port(webserviceServerPort);
+        } else {
+            this.externaGUIURIBuilder = UriComponentsBuilder
+                    .fromHttpUrl(webserviceProtocol + "://" + webserviceServerAddress)
+                    .port(webserviceServerPort);
+        }
+    }
+
+    public String getExternalServerURL() {
+        return this.externaGUIURIBuilder.toUriString();
     }
 
     public String getWebserviceServerAddress() {

src/main/resources/config/application-gui.properties

@@ -16,6 +16,7 @@ sebserver.gui.date.displayformat=de
 sebserver.gui.entrypoint=/gui
 sebserver.gui.webservice.protocol=http
 sebserver.gui.webservice.address=localhost
+sebserver.gui.webservice.address.external=${sebserver.webservice.http.external.servername}
 sebserver.gui.webservice.port=8080
 sebserver.gui.webservice.apipath=${sebserver.webservice.api.admin.endpoint}
 # defines the polling interval that is used to poll the webservice for client connection data on a monitored exam page

src/test/java/ch/ethz/seb/sebserver/gui/integration/GuiIntegrationTest.java

@@ -71,7 +71,7 @@ public abstract class GuiIntegrationTest {
 
         final HttpSession sessionMock = Mockito.mock(HttpSession.class);
         final WebserviceURIService webserviceURIService = new WebserviceURIService(
-                "http", "localhost", "8080", "/", this.endpoint);
+                "http", "localhost", "8080", "/", this.endpoint, "localhost");
 
         final ClientHttpRequestFactoryService clientHttpRequestFactoryService = Mockito
                 .mock(ClientHttpRequestFactoryService.class);