Code smell fixes

build.gradle

@@ -36,6 +36,10 @@ dependencies {
 
     // JAXB API only
     implementation 'jakarta.xml.bind:jakarta.xml.bind-api:2.3.3'
+
+    // https://central.sonatype.com/artifact/com.google.guava/guava/
+    implementation 'com.google.guava:guava:31.1-jre'
+
     //JAXB RI, Jakarta XML Binding
     runtimeOnly 'com.sun.xml.bind:jaxb-impl:2.3.8'
 

src/main/java/christophedelory/content/Content.java

@@ -353,7 +353,9 @@ public void setHeight(final int height)
      */
     public boolean isValid()
     {
-        return (_connected == null) ? false : _connected.booleanValue();
+        synchronized (this) {
+            return _connected != null && _connected.booleanValue();
+        }
     }
 
     /**
@@ -362,7 +364,6 @@ public boolean isValid()
      * @throws IllegalArgumentException if the URL is not absolute.
      * @throws MalformedURLException if a protocol handler for the URL could not be found, or if some other error occurred while constructing the URL.
      * @throws IOException if any I/O error occurs.
-     * @throws SocketTimeoutException if the timeout expires before the connection can be established.
      * @see #getURL
      */
     public void connect() throws IOException
@@ -444,7 +445,7 @@ public void connect() throws IOException
     @Override
     public boolean equals(final Object obj)
     {
-        return (obj == null) ? false : _urlString.equals(obj.toString());
+        return obj != null && _urlString.equals(obj.toString());
     }
 
     /**

src/main/java/christophedelory/content/type/ContentType.java

@@ -141,6 +141,7 @@ public PlayerSupport[] getPlayerSupports()
      * @see #setDescription
      * @see FileFilter#getDescription
      */
+    @Override
     public String getDescription()
     {
         return _description;
@@ -191,7 +192,7 @@ public boolean matchExtension(final String pattern)
     @Override
     public boolean accept(final File f)
     {
-        return (f.isDirectory()) ? true : matchExtension(f.getName()); // Throws NullPointerException if f is null.
+        return f.isDirectory() || matchExtension(f.getName()); // Throws NullPointerException if f is null.
     }
 
     /**

src/main/java/christophedelory/content/type/ContentTypesFileFilter.java

@@ -103,6 +103,7 @@ public List<ContentType> getContentTypes()
      * @return a description. Shall not be <code>null</code>.
      * @see FileFilter#getDescription
      */
+    @Override
     public String getDescription()
     {
         final StringBuilder sb = new StringBuilder(_title);

src/main/java/christophedelory/io/IOUtils.java

@@ -24,9 +24,11 @@
  */
 package christophedelory.io;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
-import java.io.IOException;
 import java.io.StringWriter;
 
 /**
@@ -51,7 +53,7 @@ public static String toString(final InputStream in, final String encoding) throw
 
         if (encoding == null)
         {
-            reader = new InputStreamReader(in); // Throws NullPointerException if in is null.
+            reader = new InputStreamReader(in, UTF_8); // Throws NullPointerException if in is null.
         }
         else
         {
@@ -62,7 +64,7 @@ public static String toString(final InputStream in, final String encoding) throw
         final char[] buffer = new char[512];
         int nb = 0;
 
-        while (-1 != (nb = reader.read(buffer))) // May throw IOException.
+        while ((nb = reader.read(buffer)) != -1) // May throw IOException.
         {
             writer.write(buffer, 0, nb);
         }

src/main/java/christophedelory/lizzy/AddToPlaylist.java

@@ -109,49 +109,49 @@ public static void main(final String[] args) throws Exception
      * The playlist type, if specified.
      */
     @Option(name="-t",usage="The output playlist type\nAllowed values: see below",metaVar="type")
-    private volatile String _type = null;
+    private String _type = null;
 
     /**
      * Specifies if the content metadata shall be fetched, if possible.
      */
     @Option(name="-m",usage="Fetch if possible the media content metadata")
-    private volatile boolean _fetchContentMetadata = false;
+    private boolean _fetchContentMetadata = false;
 
     /**
      * The sub-directories shall be recursively scanned.
      */
     @Option(name="-r",usage="Recursively add sub-directories contents")
-    private volatile boolean _recursive = false;
+    private boolean _recursive = false;
 
     /**
      * The output file or URL.
      */
     @Option(name="-o",usage="The output file or URL\nIf missing, a file save dialog is prompted\nIf the output playlist type is not specified (-t), it will be inferred from the output file name extension",metaVar="file/URL")
-    private volatile String _output = null;
+    private String _output = null;
 
     /**
      * Specifies that the marshalled M3U playlist must use the Extension M3U format.
      */
     @Option(name="-m3u:ext",usage="The output M3U playlist must use the Extension M3U format")
-    private volatile boolean _extM3U = false;
+    private boolean _extM3U = false;
 
     /**
      * Specifies that the output RSS shall make use of the RSS Media extension.
      */
     @Option(name="-rss:media",usage="The output RSS playlist must use the RSS Media format")
-    private volatile boolean _useRSSMedia = false;
+    private boolean _useRSSMedia = false;
 
     /**
      * Specifies the disk identifier of the output PLP playlist.
      */
     @Option(name="-plp:disk",usage="The disk identifier of the output PLP playlist\nExamples: HARP, HDD",metaVar="disk")
-    private volatile String _diskSpecifier = null;
+    private String _diskSpecifier = null;
 
     /**
      * The list of input files or directories.
      */
     @Argument(usage="One or more files or directories to add to the output playlist",metaVar="input-files(s)",required=true)
-    private volatile ArrayList<String> _arguments = new ArrayList<String>(); // NOPMD Avoid using implementation types; use the interface instead
+    private ArrayList<String> _arguments = new ArrayList<>(); // NOPMD Avoid using implementation types; use the interface instead
 
     /**
      * The default no-arg constructor shall not be publicly available.
@@ -493,7 +493,7 @@ else if (file.isFile()) // May throw SecurityException.
                             sb.insert(0, '/'); // Shall not throw StringIndexOutOfBoundsException.
                             final String previousFileName = previousFile.getName();
 
-                            if (!"/".equals(previousFileName) && !"\\".equals(previousFileName))
+                            if (!previousFileName.equals("/") && !previousFileName.equals("\\"))
                             {
                                 sb.insert(0, previousFileName); // Shall not throw StringIndexOutOfBoundsException.
                             }

src/main/java/christophedelory/lizzy/ContentTypeInfo.java

@@ -218,7 +218,7 @@ public static void main(final String[] args)
             sb.append("</tbody></table></body></html>");
         }
 
-        System.out.println(sb.toString()); // NOPMD System.out.print is used
+        System.out.println(sb); // NOPMD System.out.print is used
     }
 
     /**

src/main/java/christophedelory/lizzy/FetchContentMetadata.java

@@ -61,7 +61,7 @@ public void setConnect(final boolean connect)
     }
 
     @Override
-    public void beginVisitMedia(final Media target) throws Exception
+    public void beginVisitMedia(final Media target)
     {
         if (target.getSource() != null)
         {

src/main/java/christophedelory/lizzy/PlaylistToString.java

@@ -54,12 +54,9 @@ public class PlaylistToString extends BasePlaylistVisitor
 
     /**
      * Builds a new playlist visitor.
-     * @see BasePlaylistVisitor#BasePlaylistVisitor
      */
     public PlaylistToString()
     {
-        super();
-
         _sb = new StringBuilder();
         _indent = 0;
         _debug = false;
@@ -83,7 +80,7 @@ public String toString()
     }
 
     @Override
-    public void beginVisitParallel(final Parallel target) throws Exception
+    public void beginVisitParallel(final Parallel target)
     {
         addIndent();
         _sb.append("PARALLEL(x");
@@ -101,13 +98,13 @@ public void beginVisitParallel(final Parallel target) throws Exception
     }
 
     @Override
-    public void endVisitParallel(final Parallel target) throws Exception
+    public void endVisitParallel(final Parallel target)
     {
         _indent -= 2;
     }
 
     @Override
-    public void beginVisitSequence(final Sequence target) throws Exception
+    public void beginVisitSequence(final Sequence target)
     {
         addIndent();
         _sb.append("SEQUENCE(x");
@@ -125,13 +122,13 @@ public void beginVisitSequence(final Sequence target) throws Exception
     }
 
     @Override
-    public void endVisitSequence(final Sequence target) throws Exception
+    public void endVisitSequence(final Sequence target)
     {
         _indent -= 2;
     }
 
     @Override
-    public void beginVisitMedia(final Media target) throws Exception
+    public void beginVisitMedia(final Media target)
     {
         addIndent();
         _sb.append("MEDIA(x");

src/main/java/christophedelory/lizzy/Transcode.java

@@ -24,30 +24,30 @@
  */
 package christophedelory.lizzy;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+import christophedelory.playlist.Playlist;
+import christophedelory.playlist.SpecificPlaylist;
+import christophedelory.playlist.SpecificPlaylistFactory;
+import christophedelory.playlist.SpecificPlaylistProvider;
+import christophedelory.playlist.m3u.M3U;
+import christophedelory.playlist.plp.PLP;
+import christophedelory.playlist.rss.RSSProvider;
+import christophedelory.xml.Version;
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
+import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLConnection;
-import java.net.MalformedURLException;
 import java.util.ArrayList;
-
 import org.kohsuke.args4j.Argument;
 import org.kohsuke.args4j.CmdLineException;
 import org.kohsuke.args4j.CmdLineParser;
 import org.kohsuke.args4j.Option;
 
-import christophedelory.playlist.Playlist;
-import christophedelory.playlist.SpecificPlaylist;
-import christophedelory.playlist.SpecificPlaylistFactory;
-import christophedelory.playlist.SpecificPlaylistProvider;
-import christophedelory.playlist.m3u.M3U;
-import christophedelory.playlist.plp.PLP;
-import christophedelory.playlist.rss.RSSProvider;
-import christophedelory.xml.Version;
-
 /**
  * Converts a given playlist file to a specified format.
  * @since 0.2.0
@@ -73,7 +73,7 @@ public static void buildCurrentVersion(final String resourceName) throws Excepti
         final URL url = Version.class.getClassLoader().getResource(resourceName); // May throw SecurityException. Throws NullPointerException if resourceName is null.
 
         if (url != null) {
-            final BufferedReader reader = new BufferedReader(new InputStreamReader(url.openStream())); // May throw IOException. Throws NullPointerException if url is null.
+            final BufferedReader reader = new BufferedReader(new InputStreamReader(url.openStream(), UTF_8)); // May throw IOException. Throws NullPointerException if url is null.
 
             final String version = reader.readLine(); // May throw IOException.
             Version.CURRENT = Version.valueOf(version); // Throws NullPointerException if version is null. Should not throw IllegalArgumentException, IndexOutOfBoundsException, NumberFormatException.
@@ -126,55 +126,55 @@ public static void main(final String[] args) throws Exception
      * The playlist type, if specified.
      */
     @Option(name="-t",usage="The output playlist type\nAllowed values: see below\nIf missing, the input playlist type is used",metaVar="type")
-    private volatile String _type = null;
+    private String _type = null;
 
     /**
      * Specifies if the intermediate generic playlist shall be displayed or not.
      */
     @Option(name="-g",usage="Show the intermediate generic playlist")
-    private volatile boolean _showGenericPlaylist = false;
+    private boolean _showGenericPlaylist = false;
 
     /**
      * Specifies if the (parsed) input playlist shall be displayed or not.
      */
     @Option(name="-i",usage="Show the parsed input playlist")
-    private volatile boolean _showInputPlaylist = false;
+    private boolean _showInputPlaylist = false;
 
     /**
      * Specifies if the content metadata shall be fetched, if possible.
      */
     @Option(name="-m",usage="Fetch if possible the media content metadata")
-    private volatile boolean _fetchContentMetadata = false;
+    private boolean _fetchContentMetadata = false;
 
     /**
      * The output file or URL.
      */
     @Option(name="-o",usage="The output file or URL\nIf missing, stdout is used\nIf the output playlist type is not specified (-t), it will be inferred from the output file name extension",metaVar="file/URL")
-    private volatile String _output = null;
+    private String _output = null;
 
     /**
      * Specifies that the marshalled M3U playlist must use the Extension M3U format.
      */
     @Option(name="-m3u:ext",usage="The output M3U playlist must use the Extension M3U format")
-    private volatile boolean _extM3U = false;
+    private boolean _extM3U = false;
 
     /**
      * Specifies that the output RSS shall make use of the RSS Media extension.
      */
     @Option(name="-rss:media",usage="The output RSS playlist must use the RSS Media format")
-    private volatile boolean _useRSSMedia = false;
+    private boolean _useRSSMedia = false;
 
     /**
      * Specifies the disk identifier of the output PLP playlist.
      */
     @Option(name="-plp:disk",usage="The disk identifier of the output PLP playlist\nExamples: HARP, HDD",metaVar="disk")
-    private volatile String _diskSpecifier = null;
+    private String _diskSpecifier = null;
 
     /**
      * The input file or URL.
      */
     @Argument(usage="The input playlist file or URL",metaVar="input-playlist",required=true)
-    private volatile ArrayList<String> _arguments = new ArrayList<String>(); // NOPMD Avoid using implementation types; use the interface instead
+    private ArrayList<String> _arguments = new ArrayList<String>(); // NOPMD Avoid using implementation types; use the interface instead
 
     /**
      * The default no-arg constructor shall not be publicly available.

src/main/java/christophedelory/player/PlayerSupport.java

@@ -55,7 +55,7 @@ public enum Player
         VLC_MEDIA_PLAYER,
         WINAMP,
         WINDOWS_MEDIA_PLAYER,
-    };
+    }
 
     /**
      * Returns a string representation of the specified player.

src/main/java/christophedelory/playlist/AbstractPlaylistProvider.java

@@ -8,7 +8,7 @@
 
 public abstract class AbstractPlaylistProvider implements SpecificPlaylistProvider
 {
-  protected Log logger;
+  protected final Log logger;
 
   public AbstractPlaylistProvider(Class clazz) {
     this.logger = LogFactory.getLog(clazz);