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gdata/java/sample/gbase/recipe/RecipeDisplayServlet.java

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+/* Copyright (c) 2006 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package sample.gbase.recipe;
+
+import com.google.api.gbase.client.FeedURLFactory;
+import com.google.api.gbase.client.GoogleBaseEntry;
+import com.google.api.gbase.client.GoogleBaseService;
+import com.google.gdata.util.ServiceException;
+
+import java.io.IOException;
+import java.net.URL;
+
+import javax.servlet.ServletConfig;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+/**
+ * Displays a recipe.
+ */
+@SuppressWarnings("serial")
+public class RecipeDisplayServlet extends HttpServlet {
+
+  public static final String DISPLAY_JSP = "/WEB-INF/recipeDisplay.jsp";
+  
+  protected FeedURLFactory urlFactory;
+  
+  @Override
+  public void init(ServletConfig servletConfig) throws ServletException {
+    super.init(servletConfig);
+    ServletContext context = servletConfig.getServletContext();
+    urlFactory = (FeedURLFactory) 
+        context.getAttribute(RecipeListener.FEED_URL_FACTORY_ATTRIBUTE);
+  }
+
+  @Override
+  public void destroy() {
+    super.destroy();
+  }
+
+  /**
+   * Shows the page for displaying a Recipe.
+   *
+   * @param request
+   * @param response
+   * @throws ServletException
+   * @throws IOException
+   */
+  @Override
+  protected void doGet(HttpServletRequest request,
+                       HttpServletResponse response)
+      throws ServletException, IOException {
+    // This is a public page, so we use a simple, nonauthenticated service
+    GoogleBaseService service = RecipeUtil.getGoogleBaseService(request, 
+        this.getServletContext());
+    String id = request.getParameter(RecipeUtil.ID_PARAMETER);
+    recipeDisplay(request, response, service, id);
+  }
+
+  /**
+   * Retrieves a recipe and forwards the request 
+   * to the {@link #DISPLAY_JSP} jsp page that displays the recipe.
+   *
+   * @param request
+   * @param response
+   * @param service the service used to retrieve the recipe
+   * @param id the id of the recipe
+   */
+  private void recipeDisplay(HttpServletRequest request,
+                         HttpServletResponse response,
+                         GoogleBaseService service,
+                         String id)
+      throws ServletException, IOException {
+    GoogleBaseEntry entry;
+    try {
+      URL feedUrl = urlFactory.getSnippetsEntryURL(id);
+      entry = service.getEntry(feedUrl, GoogleBaseEntry.class);
+    } catch (ServiceException e) {
+      RecipeUtil.logServiceException(this, e);
+      RecipeUtil.forwardToErrorPage(request, response, e);
+      return;
+    }
+    Recipe recipe = new Recipe(entry);
+    request.setAttribute(RecipeUtil.RECIPE_ATTRIBUTE, recipe);
+    RecipeSearch results = new RecipeSearch(service, urlFactory, false);
+    RecipeUtil.setRecipeSearch(request, results);
+    // Forward to the JSP
+    request.getRequestDispatcher(DISPLAY_JSP).forward(request, response);
+  }
+}