Move index meta information

Signed-off-by: Andrew DeMaria <lostonamountain@gmail.com>

airsonic-main/src/main/java/org/airsonic/player/controller/LeftController.java

@@ -21,6 +21,7 @@ package org.airsonic.player.controller;
 
 import org.airsonic.player.domain.*;
 import org.airsonic.player.service.*;
+import org.airsonic.player.service.search.IndexManager;
 import org.airsonic.player.util.FileUtil;
 import org.airsonic.player.util.StringUtil;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -56,6 +57,8 @@ public class LeftController  {
     @Autowired
     private MediaScannerService mediaScannerService;
     @Autowired
+    private IndexManager indexManager;
+    @Autowired
     private SettingsService settingsService;
     @Autowired
     private SecurityService securityService;
@@ -116,7 +119,7 @@ public class LeftController  {
         boolean musicFolderChanged = saveSelectedMusicFolder(request);
         Map<String, Object> map = new HashMap<>();
 
-        MediaLibraryStatistics statistics = mediaScannerService.getStatistics();
+        MediaLibraryStatistics statistics = indexManager.getStatistics();
         Locale locale = RequestContextUtils.getLocale(request);
 
         boolean refresh = ServletRequestUtils.getBooleanParameter(request, "refresh", false);

airsonic-main/src/main/java/org/airsonic/player/controller/MusicFolderSettingsController.java

@@ -23,6 +23,7 @@ import org.airsonic.player.command.MusicFolderSettingsCommand;
 import org.airsonic.player.dao.AlbumDao;
 import org.airsonic.player.dao.ArtistDao;
 import org.airsonic.player.dao.MediaFileDao;
+import org.airsonic.player.domain.MediaLibraryStatistics;
 import org.airsonic.player.domain.MusicFolder;
 import org.airsonic.player.service.MediaScannerService;
 import org.airsonic.player.service.SettingsService;
@@ -103,11 +104,16 @@ public class MusicFolderSettingsController {
     private void expunge() {
 
         // to be before dao#expunge
+        MediaLibraryStatistics statistics = indexManager.getStatistics();
+        if (statistics != null) {
             LOG.debug("Cleaning search index...");
             indexManager.startIndexing();
             indexManager.expunge();
-        indexManager.stopIndexing();
+            indexManager.stopIndexing(statistics);
             LOG.debug("Search index cleanup complete.");
+        } else {
+            LOG.warn("Missing index statistics - index probably hasn't been created yet. Not expunging index.");
+        }
 
         LOG.debug("Cleaning database...");
         LOG.debug("Deleting non-present artists...");

airsonic-main/src/main/java/org/airsonic/player/domain/MediaLibraryStatistics.java

@@ -19,9 +19,10 @@
  */
 package org.airsonic.player.domain;
 
-import org.airsonic.player.util.StringUtil;
+import javax.validation.constraints.NotNull;
-import org.slf4j.Logger;
+
-import org.slf4j.LoggerFactory;
+import java.util.Date;
+import java.util.Objects;
 
 /**
  * Contains media libaray statistics, including the number of artists, albums and songs.
@@ -31,31 +32,37 @@ import org.slf4j.LoggerFactory;
  */
 public class MediaLibraryStatistics {
 
-    private static final Logger LOG = LoggerFactory.getLogger(MediaLibraryStatistics.class);
+    @NotNull
+    private Integer artistCount;
+    @NotNull
+    private Integer albumCount;
+    @NotNull
+    private Integer songCount;
+    @NotNull
+    private Long totalLengthInBytes;
+    @NotNull
+    private Long totalDurationInSeconds;
+    @NotNull
+    private Date scanDate;
 
-    private int artistCount;
+    public MediaLibraryStatistics() {
-    private int albumCount;
-    private int songCount;
-    private long totalLengthInBytes;
-    private long totalDurationInSeconds;
 
-    public MediaLibraryStatistics(int artistCount, int albumCount, int songCount, long totalLengthInBytes, long totalDurationInSeconds) {
-        this.artistCount = artistCount;
-        this.albumCount = albumCount;
-        this.songCount = songCount;
-        this.totalLengthInBytes = totalLengthInBytes;
-        this.totalDurationInSeconds = totalDurationInSeconds;
     }
 
-    public MediaLibraryStatistics() {
+    public MediaLibraryStatistics(Date scanDate) {
+        if (scanDate == null) {
+            throw new IllegalArgumentException();
+        }
+        this.scanDate = scanDate;
+        reset();
     }
 
-    public void reset() {
+    protected void reset() {
         artistCount = 0;
         albumCount = 0;
         songCount = 0;
-        totalLengthInBytes = 0;
+        totalLengthInBytes = 0L;
-        totalDurationInSeconds = 0;
+        totalDurationInSeconds = 0L;
     }
 
     public void incrementArtists(int n) {
@@ -78,42 +85,45 @@ public class MediaLibraryStatistics {
         totalDurationInSeconds += n;
     }
 
-    public int getArtistCount() {
+    public Integer getArtistCount() {
         return artistCount;
     }
 
-    public int getAlbumCount() {
+    public Integer getAlbumCount() {
         return albumCount;
     }
 
-    public int getSongCount() {
+    public Integer getSongCount() {
         return songCount;
     }
 
-    public long getTotalLengthInBytes() {
+    public Long getTotalLengthInBytes() {
         return totalLengthInBytes;
     }
 
-    public long getTotalDurationInSeconds() {
+    public Long getTotalDurationInSeconds() {
         return totalDurationInSeconds;
     }
 
-    public String format() {
+    public Date getScanDate() {
-        return artistCount + " " + albumCount + " " + songCount + " " + totalLengthInBytes + " " + totalDurationInSeconds;
+        return scanDate;
     }
 
-    public static MediaLibraryStatistics parse(String s) {
+    @Override
-        try {
+    public boolean equals(Object o) {
-            String[] strings = StringUtil.split(s);
+        if (this == o) return true;
-            return new MediaLibraryStatistics(
+        if (o == null || getClass() != o.getClass()) return false;
-                    Integer.parseInt(strings[0]),
+        MediaLibraryStatistics that = (MediaLibraryStatistics) o;
-                    Integer.parseInt(strings[1]),
+        return Objects.equals(artistCount, that.artistCount) &&
-                    Integer.parseInt(strings[2]),
+                Objects.equals(albumCount, that.albumCount) &&
-                    Long.parseLong(strings[3]),
+                Objects.equals(songCount, that.songCount) &&
-                    Long.parseLong(strings[4]));
+                Objects.equals(totalLengthInBytes, that.totalLengthInBytes) &&
-        } catch (Exception e) {
+                Objects.equals(totalDurationInSeconds, that.totalDurationInSeconds) &&
-            LOG.warn("Failed to parse media library statistics: " + s);
+                Objects.equals(scanDate, that.scanDate);
-            return new MediaLibraryStatistics();
     }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(artistCount, albumCount, songCount, totalLengthInBytes, totalDurationInSeconds, scanDate);
     }
 }

airsonic-main/src/main/java/org/airsonic/player/service/MediaScannerService.java

@@ -46,8 +46,6 @@ public class MediaScannerService {
 
     private static final Logger LOG = LoggerFactory.getLogger(MediaScannerService.class);
 
-    private MediaLibraryStatistics statistics;
-
     private boolean scanning;
     private Timer timer;
     @Autowired
@@ -69,13 +67,11 @@ public class MediaScannerService {
     @PostConstruct
     public void init() {
         indexManager.initializeIndexDirectory();
-        statistics = settingsService.getMediaLibraryStatistics();
         schedule();
     }
 
     public void initNoSchedule() {
         indexManager.deleteOldIndexFiles();
-        statistics = settingsService.getMediaLibraryStatistics();
     }
 
     /**
@@ -120,12 +116,16 @@ public class MediaScannerService {
         LOG.info("Automatic media library scanning scheduled to run every " + daysBetween + " day(s), starting at " + firstTime);
 
         // In addition, create index immediately if it doesn't exist on disk.
-        if (settingsService.getLastScanned() == null) {
+        if (neverScanned()) {
             LOG.info("Media library never scanned. Doing it now.");
             scanLibrary();
         }
     }
 
+    boolean neverScanned() {
+        return indexManager.getStatistics() == null;
+    }
+
     /**
      * Returns whether the media library is currently being scanned.
      */
@@ -165,8 +165,9 @@ public class MediaScannerService {
 
     private void doScanLibrary() {
         LOG.info("Starting to scan media library.");
-        Date lastScanned = DateUtils.truncate(new Date(), Calendar.SECOND);
+        MediaLibraryStatistics statistics = new MediaLibraryStatistics(
-        LOG.debug("New last scan date is " + lastScanned);
+                DateUtils.truncate(new Date(), Calendar.SECOND));
+        LOG.debug("New last scan date is " + statistics.getScanDate());
 
         try {
 
@@ -175,7 +176,6 @@ public class MediaScannerService {
             Genres genres = new Genres();
 
             scanCount = 0;
-            statistics.reset();
 
             mediaFileService.setMemoryCacheEnabled(false);
             indexManager.startIndexing();
@@ -185,24 +185,24 @@ public class MediaScannerService {
             // Recurse through all files on disk.
             for (MusicFolder musicFolder : settingsService.getAllMusicFolders()) {
                 MediaFile root = mediaFileService.getMediaFile(musicFolder.getPath(), false);
-                scanFile(root, musicFolder, lastScanned, albumCount, genres, false);
+                scanFile(root, musicFolder, statistics, albumCount, genres, false);
             }
 
             // Scan podcast folder.
             File podcastFolder = new File(settingsService.getPodcastFolder());
             if (podcastFolder.exists()) {
                 scanFile(mediaFileService.getMediaFile(podcastFolder), new MusicFolder(podcastFolder, null, true, null),
-                         lastScanned, albumCount, genres, true);
+                         statistics, albumCount, genres, true);
             }
 
             LOG.info("Scanned media library with " + scanCount + " entries.");
 
             LOG.info("Marking non-present files.");
-            mediaFileDao.markNonPresent(lastScanned);
+            mediaFileDao.markNonPresent(statistics.getScanDate());
             LOG.info("Marking non-present artists.");
-            artistDao.markNonPresent(lastScanned);
+            artistDao.markNonPresent(statistics.getScanDate());
             LOG.info("Marking non-present albums.");
-            albumDao.markNonPresent(lastScanned);
+            albumDao.markNonPresent(statistics.getScanDate());
 
             // Update statistics
             statistics.incrementArtists(albumCount.size());
@@ -213,21 +213,18 @@ public class MediaScannerService {
             // Update genres
             mediaFileDao.updateGenres(genres.getGenres());
 
-            settingsService.setMediaLibraryStatistics(statistics);
-            settingsService.setLastScanned(lastScanned);
-            settingsService.save(false);
             LOG.info("Completed media library scan.");
 
         } catch (Throwable x) {
             LOG.error("Failed to scan media library.", x);
         } finally {
             mediaFileService.setMemoryCacheEnabled(true);
-            indexManager.stopIndexing();
+            indexManager.stopIndexing(statistics);
             scanning = false;
         }
     }
 
-    private void scanFile(MediaFile file, MusicFolder musicFolder, Date lastScanned,
+    private void scanFile(MediaFile file, MusicFolder musicFolder, MediaLibraryStatistics statistics,
                           Map<String, Integer> albumCount, Genres genres, boolean isPodcast) {
         scanCount++;
         if (scanCount % 250 == 0) {
@@ -246,22 +243,22 @@ public class MediaScannerService {
 
         if (file.isDirectory()) {
             for (MediaFile child : mediaFileService.getChildrenOf(file, true, false, false, false)) {
-                scanFile(child, musicFolder, lastScanned, albumCount, genres, isPodcast);
+                scanFile(child, musicFolder, statistics, albumCount, genres, isPodcast);
             }
             for (MediaFile child : mediaFileService.getChildrenOf(file, false, true, false, false)) {
-                scanFile(child, musicFolder, lastScanned, albumCount, genres, isPodcast);
+                scanFile(child, musicFolder, statistics, albumCount, genres, isPodcast);
             }
         } else {
             if (!isPodcast) {
-                updateAlbum(file, musicFolder, lastScanned, albumCount);
+                updateAlbum(file, musicFolder, statistics.getScanDate(), albumCount);
-                updateArtist(file, musicFolder, lastScanned, albumCount);
+                updateArtist(file, musicFolder, statistics.getScanDate(), albumCount);
             }
             statistics.incrementSongs(1);
         }
 
         updateGenres(file, genres);
-        mediaFileDao.markPresent(file.getPath(), lastScanned);
+        mediaFileDao.markPresent(file.getPath(), statistics.getScanDate());
-        artistDao.markPresent(file.getAlbumArtist(), lastScanned);
+        artistDao.markPresent(file.getAlbumArtist(), statistics.getScanDate());
 
         if (file.getDurationSeconds() != null) {
             statistics.incrementTotalDurationInSeconds(file.getDurationSeconds());
@@ -373,15 +370,6 @@ public class MediaScannerService {
         }
     }
 
-    /**
-     * Returns media library statistics, including the number of artists, albums and songs.
-     *
-     * @return Media library statistics.
-     */
-    public MediaLibraryStatistics getStatistics() {
-        return statistics;
-    }
-
     public void setSettingsService(SettingsService settingsService) {
         this.settingsService = settingsService;
     }

airsonic-main/src/main/java/org/airsonic/player/service/SettingsService.java

@@ -96,10 +96,8 @@ public class SettingsService {
     private static final String KEY_LDAP_AUTO_SHADOWING = "LdapAutoShadowing";
     private static final String KEY_GETTING_STARTED_ENABLED = "GettingStartedEnabled";
     private static final String KEY_SETTINGS_CHANGED = "SettingsChanged";
-    private static final String KEY_LAST_SCANNED = "LastScanned";
     private static final String KEY_ORGANIZE_BY_FOLDER_STRUCTURE = "OrganizeByFolderStructure";
     private static final String KEY_SORT_ALBUMS_BY_YEAR = "SortAlbumsByYear";
-    private static final String KEY_MEDIA_LIBRARY_STATISTICS = "MediaLibraryStatistics";
     private static final String KEY_DLNA_ENABLED = "DlnaEnabled";
     private static final String KEY_DLNA_SERVER_NAME = "DlnaServerName";
     private static final String KEY_DLNA_BASE_LAN_URL = "DlnaBaseLANURL";
@@ -182,7 +180,6 @@ public class SettingsService {
     private static final long DEFAULT_SETTINGS_CHANGED = 0L;
     private static final boolean DEFAULT_ORGANIZE_BY_FOLDER_STRUCTURE = true;
     private static final boolean DEFAULT_SORT_ALBUMS_BY_YEAR = true;
-    private static final String DEFAULT_MEDIA_LIBRARY_STATISTICS = "0 0 0 0 0";
     private static final boolean DEFAULT_DLNA_ENABLED = false;
     private static final String DEFAULT_DLNA_SERVER_NAME = "Airsonic";
     private static final String DEFAULT_DLNA_BASE_LAN_URL = null;
@@ -220,6 +217,7 @@ public class SettingsService {
             "CoverArtFileTypes", "UrlRedirectCustomHost", "CoverArtLimit", "StreamPort",
             "PortForwardingEnabled", "RewriteUrl", "UrlRedirectCustomUrl", "UrlRedirectContextPath",
             "UrlRedirectFrom", "UrlRedirectionEnabled", "UrlRedirectType", "Port", "HttpsPort",
+            "MediaLibraryStatistics", "LastScanned",
             // Database settings renamed
             "database.varchar.maxlength", "database.config.type", "database.config.embed.driver",
             "database.config.embed.url", "database.config.embed.username", "database.config.embed.password",
@@ -726,19 +724,6 @@ public class SettingsService {
         return getLong(KEY_SETTINGS_CHANGED, DEFAULT_SETTINGS_CHANGED);
     }
 
-    public Date getLastScanned() {
-        String lastScanned = getProperty(KEY_LAST_SCANNED, null);
-        return lastScanned == null ? null : new Date(Long.parseLong(lastScanned));
-    }
-
-    void setLastScanned(Date date) {
-        if (date == null) {
-            setProperty(KEY_LAST_SCANNED, null);
-        } else {
-            setLong(KEY_LAST_SCANNED, date.getTime());
-        }
-    }
-
     public boolean isOrganizeByFolderStructure() {
         return getBoolean(KEY_ORGANIZE_BY_FOLDER_STRUCTURE, DEFAULT_ORGANIZE_BY_FOLDER_STRUCTURE);
     }
@@ -787,14 +772,6 @@ public class SettingsService {
         return excludePattern;
     }
 
-    public MediaLibraryStatistics getMediaLibraryStatistics() {
-        return MediaLibraryStatistics.parse(getString(KEY_MEDIA_LIBRARY_STATISTICS, DEFAULT_MEDIA_LIBRARY_STATISTICS));
-    }
-
-    void setMediaLibraryStatistics(MediaLibraryStatistics statistics) {
-        setString(KEY_MEDIA_LIBRARY_STATISTICS, statistics.format());
-    }
-
     /**
      * Returns whether we are running in Development mode.
      *

airsonic-main/src/main/java/org/airsonic/player/service/search/IndexManager.java

@@ -23,17 +23,13 @@ package org.airsonic.player.service.search;
 import org.airsonic.player.dao.AlbumDao;
 import org.airsonic.player.dao.ArtistDao;
 import org.airsonic.player.dao.MediaFileDao;
-import org.airsonic.player.domain.Album;
+import org.airsonic.player.domain.*;
-import org.airsonic.player.domain.Artist;
-import org.airsonic.player.domain.MediaFile;
-import org.airsonic.player.domain.MusicFolder;
 import org.airsonic.player.service.SettingsService;
 import org.airsonic.player.util.FileUtil;
+import org.airsonic.player.util.Util;
 import org.apache.commons.io.FileUtils;
 import org.apache.lucene.document.Document;
-import org.apache.lucene.index.IndexWriter;
+import org.apache.lucene.index.*;
-import org.apache.lucene.index.IndexWriterConfig;
-import org.apache.lucene.index.Term;
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.SearcherManager;
 import org.apache.lucene.store.FSDirectory;
@@ -47,6 +43,8 @@ import java.io.File;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.EnumMap;
+import java.util.Map;
+import java.util.Objects;
 import java.util.function.Function;
 import java.util.function.Supplier;
 import java.util.regex.Pattern;
@@ -83,6 +81,8 @@ public class IndexManager {
      */
     private static final String INDEX_ROOT_DIR_NAME = "index";
 
+    private static final String MEDIA_STATISTICS_KEY = "stats";
+
     /**
      * File supplier for index directory.
      */
@@ -221,26 +221,29 @@ public class IndexManager {
      * Close Writer of all indexes and update SearcherManager.
      * Called at the end of the Scan flow.
      */
-    public void stopIndexing() {
+    public void stopIndexing(MediaLibraryStatistics statistics) {
-        Arrays.asList(IndexType.values()).forEach(this::stopIndexing);
+        Arrays.asList(IndexType.values()).forEach(indexType -> stopIndexing(indexType, statistics));
     }
 
     /**
      * Close Writer of specified index and refresh SearcherManager.
      */
-    private void stopIndexing(IndexType type) {
+    private void stopIndexing(IndexType type, MediaLibraryStatistics statistics) {
 
         boolean isUpdate = false;
         // close
+        IndexWriter indexWriter = writers.get(type);
         try {
-            isUpdate = -1 != writers.get(type).commit();
+            Map<String,String> userData = Util.objectToStringMap(statistics);
-            writers.get(type).close();
+            indexWriter.setLiveCommitData(userData.entrySet());
+            isUpdate = -1 != indexWriter.commit();
+            indexWriter.close();
             writers.remove(type);
             LOG.trace("Success to create or update search index : [" + type + "]");
         } catch (IOException e) {
             LOG.error("Failed to create search index.", e);
         } finally {
-            FileUtil.closeQuietly(writers.get(type));
+            FileUtil.closeQuietly(indexWriter);
         }
 
         // refresh reader as index may have been written
@@ -256,6 +259,43 @@ public class IndexManager {
 
     }
 
+    /**
+     * Return the MediaLibraryStatistics saved on commit in the index. Ensures that each index reports the same data.
+     * On invalid indices, returns null.
+     */
+    public @Nullable MediaLibraryStatistics getStatistics() {
+        MediaLibraryStatistics stats = null;
+        for (IndexType indexType : IndexType.values()) {
+            IndexSearcher searcher = getSearcher(indexType);
+            if (searcher == null) {
+                LOG.trace("No index for type " + indexType);
+                return null;
+            }
+            IndexReader indexReader = searcher.getIndexReader();
+            if (!(indexReader instanceof DirectoryReader)) {
+                LOG.warn("Unexpected index type " + indexReader.getClass());
+                return null;
+            }
+            try {
+                Map<String, String> userData = ((DirectoryReader) indexReader).getIndexCommit().getUserData();
+                MediaLibraryStatistics currentStats = Util.stringMapToValidObject(MediaLibraryStatistics.class,
+                        userData);
+                if (stats == null) {
+                    stats = currentStats;
+                } else {
+                    if (!Objects.equals(stats, currentStats)) {
+                        LOG.warn("Index type " + indexType + " had differing stats data");
+                        return null;
+                    }
+                }
+            } catch (IOException | IllegalArgumentException e) {
+                LOG.warn("Exception encountered while fetching index commit data", e);
+                return null;
+            }
+        }
+        return stats;
+    }
+
     /**
      * Return the IndexSearcher of the specified index.
      * At initial startup, it may return null

airsonic-main/src/main/java/org/airsonic/player/service/upnp/FolderBasedContentDirectory.java

@@ -22,6 +22,7 @@ package org.airsonic.player.service.upnp;
 import org.airsonic.player.domain.*;
 import org.airsonic.player.service.MediaFileService;
 import org.airsonic.player.service.PlaylistService;
+import org.airsonic.player.service.search.IndexManager;
 import org.airsonic.player.util.Util;
 import org.fourthline.cling.support.contentdirectory.ContentDirectoryErrorCode;
 import org.fourthline.cling.support.contentdirectory.ContentDirectoryException;
@@ -57,6 +58,8 @@ public class FolderBasedContentDirectory extends CustomContentDirectory {
     private MediaFileService mediaFileService;
     @Autowired
     private PlaylistService playlistService;
+    @Autowired
+    private IndexManager indexManager;
 
     @Override
     public BrowseResult browse(String objectId, BrowseFlag browseFlag, String filter, long firstResult,
@@ -98,7 +101,7 @@ public class FolderBasedContentDirectory extends CustomContentDirectory {
         root.setId(CONTAINER_ID_ROOT);
         root.setParentID("-1");
 
-        MediaLibraryStatistics statistics = settingsService.getMediaLibraryStatistics();
+        MediaLibraryStatistics statistics = indexManager.getStatistics();
         root.setStorageUsed(statistics == null ? 0 : statistics.getTotalLengthInBytes());
         root.setTitle("Airsonic Media");
         root.setRestricted(true);

airsonic-main/src/main/java/org/airsonic/player/service/upnp/RootUpnpProcessor.java

@@ -20,10 +20,12 @@
 package org.airsonic.player.service.upnp;
 
 import org.airsonic.player.domain.MediaLibraryStatistics;
+import org.airsonic.player.service.search.IndexManager;
 import org.fourthline.cling.support.model.DIDLContent;
 import org.fourthline.cling.support.model.WriteStatus;
 import org.fourthline.cling.support.model.container.Container;
 import org.fourthline.cling.support.model.container.StorageFolder;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Component;
 
 import java.util.ArrayList;
@@ -35,12 +37,16 @@ import java.util.List;
  */
 @Component
 public class RootUpnpProcessor extends UpnpContentProcessor <Container, Container> {
+
+    @Autowired
+    IndexManager indexManager;
+
     public Container createRootContainer() {
         StorageFolder root = new StorageFolder();
         root.setId(DispatchingContentDirectory.CONTAINER_ID_ROOT);
         root.setParentID("-1");
 
-        MediaLibraryStatistics statistics = getDispatchingContentDirectory().getSettingsService().getMediaLibraryStatistics();
+        MediaLibraryStatistics statistics = indexManager.getStatistics();
         // returning large storageUsed values doesn't play nicely with
         // some upnp clients
         //root.setStorageUsed(statistics == null ? 0 : statistics.getTotalLengthInBytes());

airsonic-main/src/main/java/org/airsonic/player/util/Util.java

@@ -20,6 +20,8 @@
 package org.airsonic.player.util;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.DeserializationFeature;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import org.apache.commons.lang3.SystemUtils;
 import org.slf4j.Logger;
@@ -30,10 +32,12 @@ import org.springframework.web.util.UriComponentsBuilder;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
+import javax.validation.ConstraintViolation;
+import javax.validation.Validation;
+import javax.validation.Validator;
+import javax.validation.ValidatorFactory;
 
-import java.util.ArrayList;
+import java.util.*;
-import java.util.Collections;
-import java.util.List;
 
 /**
  * Miscellaneous general utility methods.
@@ -113,7 +117,11 @@ public final class Util {
         return result;
     }
 
-    static ObjectMapper objectMapper = new ObjectMapper();
+    private static ObjectMapper objectMapper = new ObjectMapper();
+    static {
+        objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+    }
+
     public static String debugObject(Object object) {
         try {
             return objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(object);
@@ -169,4 +177,29 @@ public final class Util {
             return false;
         }
     }
+
+    public static Map<String, String> objectToStringMap(Object object) {
+        TypeReference<HashMap<String, String>> typeReference = new TypeReference<HashMap<String, String>>() {};
+        return objectMapper.convertValue(object, typeReference);
+    }
+
+    public static <T> T stringMapToObject(Class<T> clazz, Map<String, String> data) {
+        return objectMapper.convertValue(data, clazz);
+    }
+
+    private static Validator validator;
+    static {
+        ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
+        validator = factory.getValidator();
+    }
+
+    public static <T> T stringMapToValidObject(Class<T> clazz, Map<String, String> data) {
+        T object = stringMapToObject(clazz, data);
+        Set<ConstraintViolation<T>> validate = validator.validate(object);
+        if (validate.isEmpty()) {
+            return object;
+        } else {
+            throw new IllegalArgumentException("Created object was not valid");
+        }
+    }
 }

airsonic-main/src/test/java/org/airsonic/player/service/MediaScannerServiceTestCase.java

@@ -178,6 +178,12 @@ public class MediaScannerServiceTestCase {
         assertNotNull(mediaFile);
     }
 
+    @Test
+    public void testNeverScanned() {
+
+        mediaScannerService.neverScanned();
+    }
+
     @Test
     public void testMusicBrainzReleaseIdTag() {
 

airsonic-main/src/test/java/org/airsonic/player/service/MediaScannerServiceUnitTest.java

@@ -0,0 +1,31 @@
+package org.airsonic.player.service;
+
+import org.airsonic.player.domain.MediaLibraryStatistics;
+import org.airsonic.player.service.search.IndexManager;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.runners.MockitoJUnitRunner;
+
+import static org.junit.Assert.*;
+import static org.mockito.Mockito.when;
+
+@RunWith(MockitoJUnitRunner.class)
+public class MediaScannerServiceUnitTest {
+
+    @InjectMocks
+    MediaScannerService mediaScannerService;
+
+    @Mock
+    IndexManager indexManager;
+
+    @Test
+    public void neverScanned() {
+        when(indexManager.getStatistics()).thenReturn(null);
+        assertTrue(mediaScannerService.neverScanned());
+
+        when(indexManager.getStatistics()).thenReturn(new MediaLibraryStatistics());
+        assertFalse(mediaScannerService.neverScanned());
+    }
+}

airsonic-main/src/test/java/org/airsonic/player/service/search/IndexManagerTestCase.java

@@ -172,7 +172,7 @@ public class IndexManagerTestCase extends AbstractAirsonicHomeTest {
         /* Does not scan, only expunges the index. */
         indexManager.startIndexing();
         indexManager.expunge();
-        indexManager.stopIndexing();
+        indexManager.stopIndexing(indexManager.getStatistics());
 
         /* 
          * Subsequent search results.

airsonic-main/src/test/java/org/airsonic/player/util/UtilTest.java

@@ -0,0 +1,88 @@
+package org.airsonic.player.util;
+
+import org.airsonic.player.domain.MediaLibraryStatistics;
+import org.junit.Test;
+
+import java.util.Date;
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.Assert.*;
+
+public class UtilTest {
+
+    @Test
+    public void objectToStringMapNull() {
+        MediaLibraryStatistics statistics = null;
+        Map<String, String> stringStringMap = Util.objectToStringMap(statistics);
+        assertNull(stringStringMap);
+    }
+
+    @Test
+    public void objectToStringMap() {
+        Date date = new Date(1568350960725L);
+        MediaLibraryStatistics statistics = new MediaLibraryStatistics(date);
+        statistics.incrementAlbums(5);
+        statistics.incrementSongs(4);
+        statistics.incrementArtists(910823);
+        statistics.incrementTotalDurationInSeconds(30);
+        statistics.incrementTotalLengthInBytes(2930491082L);
+        Map<String, String> stringStringMap = Util.objectToStringMap(statistics);
+        assertEquals("5", stringStringMap.get("albumCount"));
+        assertEquals("4", stringStringMap.get("songCount"));
+        assertEquals("910823", stringStringMap.get("artistCount"));
+        assertEquals("30", stringStringMap.get("totalDurationInSeconds"));
+        assertEquals("2930491082", stringStringMap.get("totalLengthInBytes"));
+        assertEquals("1568350960725", stringStringMap.get("scanDate"));
+    }
+
+    @Test
+    public void stringMapToObject() {
+        Map<String, String> stringStringMap = new HashMap<>();
+        stringStringMap.put("albumCount", "5");
+        stringStringMap.put("songCount", "4");
+        stringStringMap.put("artistCount", "910823");
+        stringStringMap.put("totalDurationInSeconds", "30");
+        stringStringMap.put("totalLengthInBytes", "2930491082");
+        stringStringMap.put("scanDate", "1568350960725");
+        MediaLibraryStatistics statistics = Util.stringMapToObject(MediaLibraryStatistics.class, stringStringMap);
+        assertEquals(new Integer(5), statistics.getAlbumCount());
+        assertEquals(new Integer(4), statistics.getSongCount());
+        assertEquals(new Integer(910823), statistics.getArtistCount());
+        assertEquals(new Long(30L), statistics.getTotalDurationInSeconds());
+        assertEquals(new Long(2930491082L), statistics.getTotalLengthInBytes());
+        assertEquals(new Date(1568350960725L), statistics.getScanDate());
+    }
+
+    @Test
+    public void stringMapToObjectWithExtraneousData() {
+        Map<String, String> stringStringMap = new HashMap<>();
+        stringStringMap.put("albumCount", "5");
+        stringStringMap.put("songCount", "4");
+        stringStringMap.put("artistCount", "910823");
+        stringStringMap.put("totalDurationInSeconds", "30");
+        stringStringMap.put("totalLengthInBytes", "2930491082");
+        stringStringMap.put("scanDate", "1568350960725");
+        stringStringMap.put("extraneousData", "nothingHereToLookAt");
+        MediaLibraryStatistics statistics = Util.stringMapToObject(MediaLibraryStatistics.class, stringStringMap);
+        assertEquals(new Integer(5), statistics.getAlbumCount());
+        assertEquals(new Integer(4), statistics.getSongCount());
+        assertEquals(new Integer(910823), statistics.getArtistCount());
+        assertEquals(new Long(30L), statistics.getTotalDurationInSeconds());
+        assertEquals(new Long(2930491082L), statistics.getTotalLengthInBytes());
+        assertEquals(new Date(1568350960725L), statistics.getScanDate());
+    }
+
+    public void stringMapToObjectWithNoData() {
+        Map<String, String> stringStringMap = new HashMap<>();
+        MediaLibraryStatistics statistics = Util.stringMapToObject(MediaLibraryStatistics.class, stringStringMap);
+        assertNotNull(statistics);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void stringMapToValidObjectWithNoData() {
+        Map<String, String> stringStringMap = new HashMap<>();
+        MediaLibraryStatistics statistics = Util.stringMapToValidObject(MediaLibraryStatistics.class, stringStringMap);
+    }
+
+}