Fix static resource path for WAR deployment (#17573)

Change-Id: I932794eb3a26eacfee538477937529465af1bb01

vaadin-spring-boot/src/main/java/com/vaadin/spring/boot/internal/VaadinServletConfiguration.java

@@ -29,6 +29,7 @@
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.DispatcherServlet;
 import org.springframework.web.servlet.handler.SimpleUrlHandlerMapping;
 import org.springframework.web.servlet.mvc.Controller;
 import org.springframework.web.servlet.mvc.ServletForwardingController;
@@ -42,6 +43,20 @@
  * Spring configuration that sets up a
  * {@link com.vaadin.spring.server.SpringVaadinServlet}. If you want to
  * customize the servlet, extend it and make it available as a Spring bean.
+ * <p>
+ * By default, unless a custom mapping of the Vaadin servlet is performed using
+ * the URL mapping configuration property
+ * {@link VaadinServletConfigurationProperties#getUrlMapping()}, the Vaadin
+ * servlet is mapped to a hidden path not to block requests destined to
+ * {@link DispatcherServlet}. {@link ServletForwardingController} is then mapped
+ * so that requests to all {@link SpringUI} paths are forwarded to the servlet
+ * for the generation of a bootstrap page, which internally uses the Vaadin
+ * servlet path for all other communication.
+ * <p>
+ * This approach currently relies on a hack that modifies request servlet path
+ * and path info on the fly as those produced by
+ * {@link ServletForwardingController} are not what {@link VaadinServlet}
+ * expects. See {@link SpringVaadinServlet} for more information on this.
  *
  * @author Petter Holmström (petter@vaadin.com)
  * @author Henri Sara (hesara@vaadin.com)
@@ -161,7 +176,7 @@ protected String[] getUrlMappings() {
     }
 
     @Bean
-    ServletRegistrationBean vaadinServletRegistration() {
+    protected ServletRegistrationBean vaadinServletRegistration() {
         return createServletRegistrationBean();
     }
 
@@ -172,12 +187,7 @@ public void afterPropertiesSet() throws Exception {
 
     @Bean
     public VaadinServlet vaadinServlet() {
-        SpringVaadinServlet servlet = new SpringVaadinServlet();
-        // TODO should this rather be done when registering the servlet
-        if (isMappedToRoot()) {
-            servlet.setServiceUrl(DEFAULT_SERVLET_URL_BASE);
-        }
-        return servlet;
+        return new SpringVaadinServlet();
     }
 
     protected ServletRegistrationBean createServletRegistrationBean() {
@@ -186,6 +196,15 @@ protected ServletRegistrationBean createServletRegistrationBean() {
         getLogger().info("Servlet will be mapped to URLs {}",
                 (Object) urlMappings);
         final VaadinServlet servlet = vaadinServlet();
+
+        // this is a hack to make is possible for Vaadin and Spring MVC
+        // applications to co-exist in the same global "namespace"
+        if (servlet instanceof SpringVaadinServlet && isMappedToRoot()) {
+            SpringVaadinServlet vaadinServlet = (SpringVaadinServlet) servlet;
+            vaadinServlet.setServiceUrl(DEFAULT_SERVLET_URL_BASE);
+            vaadinServlet.setClearServletPath(true);
+        }
+
         final ServletRegistrationBean registrationBean = new ServletRegistrationBean(
                 servlet, urlMappings);
         addInitParameters(registrationBean);

vaadin-spring/src/main/java/com/vaadin/spring/server/SpringVaadinServlet.java

@@ -43,6 +43,15 @@
  * If you need a custom Vaadin servlet, you can either extend this servlet
  * directly, or extend another subclass of {@link VaadinServlet} and just add
  * the UI provider.
+ * <p>
+ * This servlet also implements a hack to get around the behavior of Spring
+ * ServletForwardingController/ServletWrappingController. Those controllers
+ * return null as the pathInfo of requests forwarded to the Vaadin servlet, and
+ * use the mapping as the servlet path whereas with Vaadin the mapping typically
+ * corresponds to a UI, not a virtual servlet. Thus, there is an option to clear
+ * the servlet path in requests and compute pathInfo accordingly. This is used
+ * by Vaadin Spring Boot to make it easier to use Vaadin and Spring MVC
+ * applications together in the same global "namespace".
  *
  * @author Petter Holmström (petter@vaadin.com)
  * @author Josh Long (josh@joshlong.com)
@@ -53,6 +62,8 @@ public class SpringVaadinServlet extends VaadinServlet {
 
     private String serviceUrl = null;
 
+    private boolean clearServletPath = false;
+
     @Override
     protected void servletInitialized() throws ServletException {
         getService().addSessionInitListener(new SessionInitListener() {
@@ -111,10 +122,39 @@ public void setServiceUrl(String serviceUrl) {
         this.serviceUrl = serviceUrl;
     }
 
+    /**
+     * Return true if always forcing the servlet path to be the empty string,
+     * false otherwise.
+     *
+     * This API might change in future versions.
+     *
+     * @see SpringVaadinServlet
+     *
+     * @return true if clearing the servlet path
+     */
+    public boolean isClearServletPath() {
+        return clearServletPath;
+    }
+
+    /**
+     * Make the servlet use empty string as the servlet path (needed when using
+     * ServletForwardingController). See the class level javadoc for
+     * {@link SpringVaadinServlet} for more information.
+     *
+     * This API might change in future versions.
+     *
+     * @param clearServletPath
+     *            true to use empty servlet path and have the full path as
+     *            pathInfo, false not to remap the servlet path
+     */
+    public void setClearServletPath(boolean clearServletPath) {
+        this.clearServletPath = clearServletPath;
+    }
+
     @Override
     protected VaadinServletService createServletService(
             DeploymentConfiguration deploymentConfiguration)
-                    throws ServiceException {
+            throws ServiceException {
         // this is needed when using a custom service URL
         SpringVaadinServletService service = new SpringVaadinServletService(
                 this, deploymentConfiguration, getServiceUrl());
@@ -125,7 +165,8 @@ protected VaadinServletService createServletService(
     @Override
     protected VaadinServletRequest createVaadinRequest(
             HttpServletRequest request) {
-        return new SpringVaadinServletRequest(request, getService());
+        return new SpringVaadinServletRequest(request, getService(),
+                isClearServletPath());
     }
 
 }

vaadin-spring/src/main/java/com/vaadin/spring/server/SpringVaadinServletRequest.java

@@ -28,22 +28,44 @@
  */
 public class SpringVaadinServletRequest extends VaadinServletRequest {
 
+    private UrlPathHelper urlPathHelper = new UrlPathHelper();
+    private boolean clearServletPath;
+
     /**
      * Construct a Spring servlet request
      *
      * @param request
      * @param vaadinService
+     * @param clearServletPath
+     *            true to use empty string as the servlet path (needed when
+     *            using ServletForwardingController for bootstrap page
+     *            requests), false to use the normal servlet path - for more
+     *            information on this hack, see {@link SpringVaadinServlet}
      */
     public SpringVaadinServletRequest(HttpServletRequest request,
-            VaadinServletService vaadinService) {
+            VaadinServletService vaadinService, boolean clearServletPath) {
         super(request, vaadinService);
+        this.clearServletPath = clearServletPath;
+    }
+
+    @Override
+    public String getServletPath() {
+        if (clearServletPath) {
+            // the path where a ServletForwardingController is registered is not
+            // a real servlet path
+            return "";
+        } else {
+            return super.getServletPath();
+        }
     }
 
     @Override
     public String getPathInfo() {
         String pathInfo = super.getPathInfo();
         if (pathInfo == null) {
-            pathInfo = new UrlPathHelper().getPathWithinApplication(this);
+            // this uses getServletPath() and should work both with and without
+            // clearServletPath
+            pathInfo = urlPathHelper.getPathWithinServletMapping(this);
         }
         return pathInfo;
     }