Make a couple JavaDoc fixes.

src/main/java/org/torproject/onionoo/docs/NodeStatus.java

@@ -29,7 +29,7 @@ import java.util.stream.Collectors;
  * are relevant descriptors, consensuses or other documents available.
  *
  * <p>At the end of each run of the hourly updater, these documents are
- * concatenated and written to a single file in <code>status/summary</code>.
+ * concatenated and written to a single file in {@code status/summary}.
  * Each line contains a single document.
  *
  * <p>A new NodeStatus can be created from a string using the

src/main/java/org/torproject/onionoo/docs/SummaryDocument.java

@@ -58,7 +58,7 @@ public class SummaryDocument extends Document {
   @JsonIgnore
   private transient String hashedFingerprint = null;
 
-  /** Returns the SHA1-hashed fingerprint, or <code>null</code> if no
+  /** Returns the SHA1-hashed fingerprint, or {@code null} if no
    * fingerprint is set. */
   public String getHashedFingerprint() {
     if (this.hashedFingerprint == null && this.fingerprint != null) {
@@ -75,7 +75,7 @@ public class SummaryDocument extends Document {
   @JsonIgnore
   private transient String base64Fingerprint = null;
 
-  /** Returns the base64-encoded fingerprint, or <code>null</code> if no
+  /** Returns the base64-encoded fingerprint, or {@code null} if no
    * fingerprint is set. */
   public String getBase64Fingerprint() {
     if (this.base64Fingerprint == null && this.fingerprint != null) {
@@ -93,7 +93,7 @@ public class SummaryDocument extends Document {
   private transient String[] fingerprintSortedHexBlocks = null;
 
   /** Returns a sorted array containing blocks of 4 upper-case hex
-   * characters from the fingerprint, or <code>null</code> if no
+   * characters from the fingerprint, or {@code null} if no
    * fingerprint is set. */
   public String[] getFingerprintSortedHexBlocks() {
     if (this.fingerprintSortedHexBlocks == null && this.fingerprint != null) {

src/main/java/org/torproject/onionoo/server/NodeIndexer.java

@@ -61,8 +61,8 @@ public class NodeIndexer implements ServletContextListener, Runnable {
   private Thread nodeIndexerThread = null;
 
   /** Returns the creation time of the last known node index in
-   * milliseconds since the epoch, or <code>-1</code> if no node index
-   * could be retrieved within <code>timeoutMillis</code> milliseconds. */
+   * milliseconds since the epoch, or {@code -1} if no node index
+   * could be retrieved within {@code timeoutMillis} milliseconds. */
   public synchronized long getLastIndexed(long timeoutMillis) {
     if (this.lastIndexed == -1L && this.nodeIndexerThread != null
         && timeoutMillis > 0L) {
@@ -77,7 +77,7 @@ public class NodeIndexer implements ServletContextListener, Runnable {
   }
 
   /** Returns the last known node index, or null if no node index could be
-   * retrieved within <code>timeoutMillis</code> milliseconds. */
+   * retrieved within {@code timeoutMillis} milliseconds. */
   public synchronized NodeIndex getLatestNodeIndex(long timeoutMillis) {
     if (this.latestNodeIndex == null && this.nodeIndexerThread != null
         && timeoutMillis > 0L) {

src/main/java/org/torproject/onionoo/server/ResourceServlet.java

@@ -86,8 +86,8 @@ public class ResourceServlet extends HttpServlet {
     doGet(request, response, System.currentTimeMillis());
   }
 
-  /** Handles the HTTP GET request in the wrapped <code>request</code> by
-   * writing an HTTP GET response to the likewise <code>response</code>,
+  /** Handles the HTTP GET request in the wrapped {@code request} by
+   * writing an HTTP GET response to the likewise {@code response},
    * both of which are wrapped to facilitate testing. */
   @SuppressWarnings("checkstyle:variabledeclarationusagedistance")
   public void doGet(HttpServletRequestWrapper request,

src/main/java/org/torproject/onionoo/updater/LookupService.java

@@ -98,7 +98,7 @@ public class LookupService {
   }
 
   /** Looks up address strings in the configured
-   * <code>GeoLite2-City-*.csv</code> and <code>GeoIPASNum2.csv</code>
+   * {@code GeoLite2-City-*.csv} and {@code GeoIPASNum2.csv}
    * files and returns all lookup results. */
   public SortedMap<String, LookupResult> lookup(
       SortedSet<String> addressStrings) {

src/main/java/org/torproject/onionoo/util/FormattingUtils.java

@@ -25,7 +25,7 @@ public class FormattingUtils {
   private static final long ONE_MINUTE = 60L * ONE_SECOND;
 
   /** Formats the given number of milliseconds using the format
-   * <code>"${minutes}:${seconds}.{milliseconds} minutes"</code>. */
+   * {@code "${minutes}:${seconds}.{milliseconds} minutes"}. */
   public static String formatMillis(long millis) {
     return String.format("%02d:%02d.%03d minutes", millis / ONE_MINUTE,
         (millis % ONE_MINUTE) / ONE_SECOND, millis % ONE_SECOND);