71734: Sitemap REST controller

dspace-server-webapp/src/main/java/org/dspace/app/rest/SitemapRestController.java

@@ -0,0 +1,148 @@
+/**
+ * The contents of this file are subject to the license and copyright
+ * detailed in the LICENSE and NOTICE files at the root of the source
+ * tree and available online at
+ *
+ * http://www.dspace.org/license/
+ */
+package org.dspace.app.rest;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.sql.SQLException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import javassist.NotFoundException;
+import org.apache.catalina.connector.ClientAbortException;
+import org.apache.logging.log4j.Logger;
+import org.dspace.app.rest.model.RestModel;
+import org.dspace.app.rest.utils.ContextUtil;
+import org.dspace.app.rest.utils.MultipartFileSender;
+import org.dspace.core.Context;
+import org.dspace.services.ConfigurationService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.RestController;
+
+/**
+ * This is a specialized controller to provide access to the sitemap files, generated by
+ * {@link org.dspace.app.sitemap.GenerateSitemaps}
+ *
+ * The mapping for requested endpoint try to resolve a valid sitemap file name, for example
+ * <pre>
+ * {@code
+ * https://<dspace.server.url>/api/discover/sitemaps/26453b4d-e513-44e8-8d5b-395f62972eff/sitemap0.html
+ * }
+ * </pre>
+ *
+ * @author Maria Verdonck (Atmire) on 08/07/2020
+ */
+@RestController
+@RequestMapping("/api/" + RestModel.DISCOVER + "/sitemaps")
+public class SitemapRestController {
+
+    private static final Logger log = org.apache.logging.log4j.LogManager.getLogger(SitemapRestController.class);
+
+    @Autowired
+    ConfigurationService configurationService;
+
+    // Most file systems are configured to use block sizes of 4096 or 8192 and our buffer should be a multiple of that.
+    private static final int BUFFER_SIZE = 4096 * 10;
+
+    /**
+     * Tries to retrieve a matching sitemap file in configured location
+     *
+     * @param name     the name of the requested sitemap file
+     * @param response the HTTP response
+     * @param request  the HTTP request
+     * @throws NotFoundException if no matching sitemap file can be found
+     * @throws SQLException      if db error while completing DSpace context
+     * @throws IOException       if IO error surrounding sitemap file
+     */
+    @RequestMapping(method = {RequestMethod.GET, RequestMethod.HEAD}, value = "/{name}")
+    public void retrieve(@PathVariable String name, HttpServletResponse response,
+        HttpServletRequest request) throws NotFoundException, IOException, SQLException {
+        // Find sitemap with given name in dspace/sitemaps
+        File foundSitemapFile = null;
+        File sitemapOutputDir = new File(configurationService.getProperty("sitemap.dir"));
+        if (sitemapOutputDir.exists() && sitemapOutputDir.isDirectory()) {
+            // List of all files and directories inside sitemapOutputDir
+            File sitemapFilesList[] = sitemapOutputDir.listFiles();
+            for (File sitemapFile : sitemapFilesList) {
+                if (name.equalsIgnoreCase(sitemapFile.getName())) {
+                    if (sitemapFile.isFile()) {
+                        foundSitemapFile = sitemapFile;
+                    } else {
+                        throw new NotFoundException(
+                            "Directory with name " + name + " in " + sitemapOutputDir.getAbsolutePath() +
+                            " found, but no file");
+                    }
+                }
+            }
+        } else {
+            throw new NotFoundException("Sitemap directory in " + sitemapOutputDir.getAbsolutePath() + " does not " +
+                                        "exist, either sitemaps have not been generated, or are located elsewhere.");
+        }
+        if (foundSitemapFile == null) {
+            throw new NotFoundException(
+                "Could not find sitemap file with name " + name + " in " + sitemapOutputDir.getAbsolutePath());
+        } else {
+            // return found sitemap file
+            this.returnSitemapFile(foundSitemapFile, response, request);
+        }
+    }
+
+    /**
+     * Sends back the matching sitemap file as a MultipartFile, with the headers set with details of the file
+     * (content, size, name, last modified)
+     *
+     * @param foundSitemapFile the found sitemap file, with matching name as in request path
+     * @param response         the HTTP response
+     * @param request          the HTTP request
+     * @throws SQLException if db error while completing DSpace context
+     * @throws IOException  if IO error surrounding sitemap file
+     */
+    private void returnSitemapFile(File foundSitemapFile, HttpServletResponse response, HttpServletRequest request)
+        throws SQLException, IOException {
+        // Pipe the bits
+        try (InputStream is = new FileInputStream(foundSitemapFile)) {
+            MultipartFileSender sender = MultipartFileSender
+                .fromInputStream(is)
+                .withBufferSize(BUFFER_SIZE)
+                .withFileName(foundSitemapFile.getName())
+                .withLength(foundSitemapFile.length())
+                .withMimetype(Files.probeContentType(foundSitemapFile.toPath()))
+                .with(request)
+                .with(response);
+
+            sender.withLastModified(foundSitemapFile.lastModified());
+
+            // Determine if we need to send the file as a download or if the browser can open it inline
+            long dispositionThreshold = configurationService.getLongProperty("webui.content_disposition_threshold");
+            if (dispositionThreshold >= 0 && foundSitemapFile.length() > dispositionThreshold) {
+                sender.withDisposition(MultipartFileSender.CONTENT_DISPOSITION_ATTACHMENT);
+            }
+
+            Context context = ContextUtil.obtainContext(request);
+
+            // We have all the data we need, close the connection to the database so that it doesn't stay open during
+            // download/streaming
+            context.complete();
+
+            // Send the data
+            if (sender.isValid()) {
+                sender.serveResource();
+            }
+
+        } catch (ClientAbortException e) {
+            log.debug("Client aborted the request before the download was completed. " +
+                      "Client is probably switching to a Range request.", e);
+        }
+    }
+}