added PushStateDispatcher for production and development to WebResourceServlet

scm-webapp/src/main/java/sonia/scm/ForwardingPushStateDispatcher.java

@@ -0,0 +1,24 @@
+package sonia.scm;
+
+import javax.servlet.RequestDispatcher;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+/**
+ * This dispatcher forwards every request to the index.html of the application.
+ *
+ * @since 2.0.0
+ */
+public class ForwardingPushStateDispatcher implements PushStateDispatcher {
+  @Override
+  public void dispatch(HttpServletRequest request, HttpServletResponse response, String uri) throws IOException {
+    RequestDispatcher dispatcher = request.getRequestDispatcher("/index.html");
+    try {
+      dispatcher.forward(request, response);
+    } catch (ServletException e) {
+      throw new IOException("failed to forward request", e);
+    }
+  }
+}