Determine init parameters by reflection over com.vaadin.flow.server.I…

…nitParameters (#627) (#630)

* Determine init parameters by reflection over com.vaadin.flow.server.InitParameters (#627)

pom.xml

@@ -44,7 +44,7 @@
         <maven.compiler.target>1.8</maven.compiler.target>
 
         <!-- These are typically overridden with BOMs -->
-        <vaadin.flow.version>2.2-SNAPSHOT</vaadin.flow.version>
+        <vaadin.flow.version>2.3-SNAPSHOT</vaadin.flow.version>
         <spring-boot.version>2.2.0.RELEASE</spring-boot.version>
 
         <!-- Additional manifest fields -->

vaadin-spring/src/main/java/com/vaadin/flow/spring/SpringServlet.java

@@ -23,17 +23,17 @@
 import java.util.Arrays;
 import java.util.List;
 import java.util.Properties;
+import java.util.stream.Collectors;
 
 import org.springframework.context.ApplicationContext;
 import org.springframework.core.env.Environment;
 import org.springframework.web.servlet.mvc.ServletForwardingController;
 
 import com.vaadin.flow.function.DeploymentConfiguration;
-import com.vaadin.flow.server.Constants;
+import com.vaadin.flow.server.InitParameters;
 import com.vaadin.flow.server.ServiceException;
 import com.vaadin.flow.server.VaadinServlet;
 import com.vaadin.flow.server.VaadinServletService;
-import com.vaadin.flow.server.VaadinSession;
 
 /**
  * Spring application context aware Vaadin servlet implementation.
@@ -54,35 +54,22 @@ public class SpringServlet extends VaadinServlet {
     /**
      * Property names that are read from the application.properties file
      */
-    protected static final List<String> PROPERTY_NAMES = Arrays.asList(
-            Constants.SERVLET_PARAMETER_PRODUCTION_MODE,
-            Constants.SERVLET_PARAMETER_DISABLE_XSRF_PROTECTION,
-            Constants.SERVLET_PARAMETER_CLOSE_IDLE_SESSIONS,
-            Constants.SERVLET_PARAMETER_HEARTBEAT_INTERVAL,
-            Constants.SERVLET_PARAMETER_SEND_URLS_AS_PARAMETERS,
-            Constants.SERVLET_PARAMETER_PUSH_MODE,
-            Constants.SERVLET_PARAMETER_PUSH_URL,
-            Constants.SERVLET_PARAMETER_SYNC_ID_CHECK,
-            Constants.SERVLET_PARAMETER_PUSH_SUSPEND_TIMEOUT_LONGPOLLING,
-            Constants.SERVLET_PARAMETER_REQUEST_TIMING,
-            Constants.SERVLET_PARAMETER_COMPATIBILITY_MODE,
-            Constants.SERVLET_PARAMETER_DEVMODE_WEBPACK_ERROR_PATTERN,
-            Constants.SERVLET_PARAMETER_DEVMODE_WEBPACK_OPTIONS,
-            Constants.SERVLET_PARAMETER_DEVMODE_WEBPACK_SUCCESS_PATTERN,
-            Constants.SERVLET_PARAMETER_DEVMODE_WEBPACK_TIMEOUT,
-            Constants.SERVLET_PARAMETER_ENABLE_DEV_SERVER,
-            Constants.SERVLET_PARAMETER_JSBUNDLE,
-            Constants.SERVLET_PARAMETER_POLYFILLS,
-            Constants.SERVLET_PARAMETER_STATISTICS_JSON,
-            Constants.SERVLET_PARAMETER_ENABLE_PNPM,
-            Constants.DISABLE_WEBJARS, Constants.SERVLET_PARAMETER_BROTLI,
-            Constants.LOAD_ES5_ADAPTERS,
-            Constants.USE_ORIGINAL_FRONTEND_RESOURCES,
-            Constants.FRONTEND_URL_ES5, Constants.FRONTEND_URL_ES6,
-            Constants.I18N_PROVIDER,
-            Constants.DISABLE_AUTOMATIC_SERVLET_REGISTRATION,
-            "devmode.liveReload.enabled",
-            VaadinSession.UI_PARAMETER);
+
+    protected static final List<String> PROPERTY_NAMES = Arrays
+            .stream(InitParameters.class.getDeclaredFields())
+            // thanks to java code coverage which adds non-existent
+            // initially variables everywhere: we should skip this extra
+            // field
+            .filter(field -> !field.isSynthetic())
+            .map(field -> {
+                try {
+                    return (String) field.get(null);
+                } catch (IllegalAccessException e) {
+                    throw new IllegalStateException("unable to access field",
+                            e);
+                }
+            })
+            .collect(Collectors.toList());
 
     private final ApplicationContext context;
     private final boolean forwardingEnforced;