Fix JSON responses

Author: LEDfan

src/main/java/eu/openanalytics/containerproxy/api/ProxyRouteController.java

@@ -23,6 +23,7 @@
 import eu.openanalytics.containerproxy.model.runtime.Proxy;
 import eu.openanalytics.containerproxy.service.ProxyService;
 import eu.openanalytics.containerproxy.service.UserService;
+import eu.openanalytics.containerproxy.util.ImmediateJsonResponse;
 import eu.openanalytics.containerproxy.util.ProxyMappingManager;
 import eu.openanalytics.containerproxy.util.ContextPathHelper;
 import org.springframework.stereotype.Controller;

src/main/java/eu/openanalytics/containerproxy/auth/impl/oidc/OpenIdReAuthorizeFilter.java

@@ -20,6 +20,7 @@
  */
 package eu.openanalytics.containerproxy.auth.impl.oidc;
 
+import eu.openanalytics.containerproxy.util.ImmediateJsonResponse;
 import org.springframework.core.env.Environment;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.core.context.SecurityContextHolder;
@@ -132,8 +133,7 @@ protected void doFilterInternal(@Nonnull HttpServletRequest request, @Nonnull Ht
             }
         }
         if (REFRESH_OPENID_MATCHER.matches(request)) {
-            response.getWriter().write("{\"status\":\"success\"}");
-            response.setStatus(200);
+            ImmediateJsonResponse.write(response, 200, "{\"status\":\"success\"}");
             return;
         }
         chain.doFilter(request, response);
@@ -156,8 +156,7 @@ private void invalidateSession(@Nonnull HttpServletRequest request, @Nonnull Htt
             session.invalidate();
         }
         if (REFRESH_OPENID_MATCHER.matches(request)) {
-            response.getWriter().write("{\"status\":\"success\"}");
-            response.setStatus(200);
+            ImmediateJsonResponse.write(response, 200, "{\"status\":\"success\"}");
         } else {
             throw new ClientAuthorizationRequiredException(REG_ID);
         }

src/main/java/eu/openanalytics/containerproxy/util/ImmediateJsonResponse.java

@@ -0,0 +1,43 @@
+/**
+ * ContainerProxy
+ *
+ * Copyright (C) 2016-2023 Open Analytics
+ *
+ * ===========================================================================
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the Apache License as published by
+ * The Apache Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * Apache License for more details.
+ *
+ * You should have received a copy of the Apache License
+ * along with this program.  If not, see <http://www.apache.org/licenses/>
+ */
+package eu.openanalytics.containerproxy.util;
+
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+public class ImmediateJsonResponse {
+
+    /**
+     * Helper that writes a JSON response to a HttpServletResponse without using Spring.
+     * This can be used in places where no Spring logic can be used (e.g. Filters)
+     * @param response the response to write into
+     * @param status the status code of the response
+     * @param json the jsons string to write
+     * @throws IOException
+     */
+    public static void write(HttpServletResponse response, int status, String json) throws IOException {
+        response.setCharacterEncoding("UTF-8");
+        response.setContentType("application/json");
+        response.getWriter().write(json);
+        response.setStatus(status);
+    }
+
+}