Fix java linting

bot/build.gradle.kts

@@ -34,6 +34,8 @@ plugins {
     id("com.github.breadmoirai.github-release")
 }
 
+val pmdVersion = "7.0.0-rc4"
+
 val numberVersion = "3.108.0"
 
 project.group = "me.duncte123.skybot"
@@ -69,6 +71,9 @@ dependencies {
     implementation(libs.redis)
     implementation(libs.mariadb)
     implementation(libs.bundles.database)
+
+    pmd("net.sourceforge.pmd:pmd-ant:$pmdVersion")
+    pmd("net.sourceforge.pmd:pmd-java:$pmdVersion")
 }
 
 val compileKotlin: KotlinCompile by tasks
@@ -183,7 +188,7 @@ kotlinter {
 
 pmd {
     isConsoleOutput = true
-    toolVersion = "6.55.0"
+    toolVersion = pmdVersion
     rulesMinimumPriority.set(5)
     ruleSets = listOf()
     ruleSetFiles(File("linters/pmd.xml"))

bot/linters/pmd.xml

@@ -43,7 +43,8 @@
         <exclude name="OnlyOneReturn"/>
         <exclude name="UseUnderscoresInNumericLiterals"/>
         <exclude name="TooManyStaticImports"/>
-        <exclude name="DefaultPackage"/>
+        <exclude name="CommentDefaultAccessModifier"/>
+        <exclude name="UselessParentheses"/>
         <exclude name="LinguisticNaming"/>
     </rule>
 
@@ -66,6 +67,7 @@
         <exclude name="TooManyMethods"/>
         <exclude name="NcssCount"/>
         <exclude name="ExcessiveMethodLength"/>
+        <exclude name="MutableStaticState"/>
     </rule>
 
     <rule ref="category/java/design.xml/NPathComplexity">
@@ -74,6 +76,26 @@
         </properties>
     </rule>
 
+    <!-- TODO: make sure this is as low as you can get it -->
+    <rule ref="category/java/design.xml/CognitiveComplexity">
+        <properties>
+            <property name="reportLevel" value="40" />
+        </properties>
+    </rule>
+
+    <rule ref="category/java/bestpractices.xml/LooseCoupling">
+        <properties>
+            <property name="allowedTypes" value="java.util.Properties,com.jagrosh.jagtag.Environment,me.duncte123.skybot.objects.DBMap" />
+        </properties>
+    </rule>
+
+    <!-- TODO: make sure this is as low as you can get it -->
+    <rule ref="category/java/design.xml/CouplingBetweenObjects">
+        <properties>
+            <property name="threshold" value="40" />
+        </properties>
+    </rule>
+
     <rule ref="category/java/errorprone.xml/AssignmentInOperand">
         <properties>
             <property name="allowIf" value="false" />
@@ -89,18 +111,19 @@
 
     <rule ref="category/java/errorprone.xml">
         <exclude name="AvoidCatchingThrowable"/>
+        <exclude name="AssignmentToNonFinalStatic"/>
         <exclude name="CallSuperFirst"/>
         <exclude name="CallSuperLast"/>
         <exclude name="CloseResource"/>
         <exclude name="DoNotCallGarbageCollectionExplicitly"/>
         <exclude name="DoNotTerminateVM"/>
         <exclude name="MissingSerialVersionUID"/>
         <exclude name="OverrideBothEqualsAndHashcode"/>
-        <exclude name="BeanMembersShouldSerialize"/>
         <exclude name="AvoidLiteralsInIfCondition"/>
         <exclude name="UseLocaleWithCaseConversions"/>
         <exclude name="AvoidDuplicateLiterals"/>
         <exclude name="SimpleDateFormatNeedsLocale"/>
+        <exclude name="ReturnEmptyCollectionRatherThanNull"/>
     </rule>
 
     <rule ref="category/java/multithreading.xml">

bot/src/main/java/fredboat/audio/player/LavalinkManager.java

@@ -107,11 +107,7 @@ public boolean isConnected(Guild guild) {
     }
 
     public boolean isConnected(long guildId) {
-        if (!isEnabled()) {
-            return false;
-        }
-
-        return lavalink.getLink(guildId).getState() == LinkState.CONNECTED;
+        return !isEnabled() || lavalink.getLink(guildId).getState() == LinkState.CONNECTED;
     }
 
     @SuppressWarnings("ConstantConditions") // cache is enabled

bot/src/main/java/me/duncte123/skybot/SkyBot.java

@@ -56,10 +56,10 @@
 import static net.dv8tion.jda.api.utils.MemberCachePolicy.PENDING;
 
 public final class SkyBot {
-    public static ScheduledExecutorService SYSTEM_POOL = Executors.newSingleThreadScheduledExecutor((r) -> {
-        final Thread t = new Thread(r, "System Pool");
-        t.setDaemon(true);
-        return t;
+    public static final ScheduledExecutorService SYSTEM_POOL = Executors.newSingleThreadScheduledExecutor((r) -> {
+        final Thread thread = new Thread(r, "System Pool");
+        thread.setDaemon(true);
+        return thread;
     });
 
     private static SkyBot instance;

bot/src/main/java/me/duncte123/skybot/commands/essentials/TestTagCommand.java

@@ -31,6 +31,7 @@
 import static me.duncte123.botcommons.messaging.MessageUtils.sendEmbed;
 import static me.duncte123.botcommons.messaging.MessageUtils.sendMsg;
 
+@SuppressWarnings("PMD.TestClassWithoutTestCases")
 public class TestTagCommand extends Command {
 
     public TestTagCommand() {

bot/src/main/java/me/duncte123/skybot/commands/guild/mod/CleanupCommand.java

@@ -268,7 +268,7 @@ private void handleComplete(int count, CommandContext ctx) {
      *
      * @return the future with a different timeout
      */
-    @SuppressWarnings({"rawtypes", "unchecked"})
+    @SuppressWarnings({"rawtypes", "unchecked", "PMD.AvoidAccessibilityAlteration"})
     private CompletableFuture<Void> hackTimeout(CompletableFuture<Void> future) {
         if (!(future instanceof RestFuture)) {
             // Ignore stuff that is not a rest future

bot/src/main/java/me/duncte123/skybot/commands/image/ImageCommandBase.java

@@ -62,7 +62,7 @@ private boolean canSendFile(CommandContext ctx) {
     }
 
     @SuppressWarnings("BooleanMethodIsAlwaysInverted")
-        /* package */ boolean passes(CommandContext ctx) {
+    /* package */ boolean passes(CommandContext ctx) {
         return passes(ctx, true);
     }
 
@@ -120,18 +120,18 @@ protected String getImageFromCommand(CommandContext ctx) {
 
         // I hate this so much
         // But I won't change one pmd rule just for the sake of using !isEmpty here
-        if (ctx.getMessage().getAttachments().size() > 0) {
+        if (ctx.getMessage().getAttachments().isEmpty()) {
             url = tryGetAttachment(ctx);
         } else if (!mentionedUsers.isEmpty()) {
-            url = getAvatarUrl(mentionedUsers.get(0));
+            url = getAvatarUrl(mentionedUsers.getFirst());
         } else if (!args.isEmpty()) {
-            if (AirUtils.isURL(args.get(0))) {
-                url = tryGetUrl(ctx, args.get(0));
+            if (AirUtils.isURL(args.getFirst())) {
+                url = tryGetUrl(ctx, args.getFirst());
             } else {
                 final List<Member> textMentions = FinderUtils.searchMembers(ctx.getArgsJoined(), ctx);
 
                 if (!textMentions.isEmpty()) {
-                    url = getAvatarUrl(textMentions.get(0).getUser());
+                    url = getAvatarUrl(textMentions.getFirst().getUser());
                 }
             }
         }
@@ -145,7 +145,7 @@ protected String getImageFromCommand(CommandContext ctx) {
 
     @Nullable
     private String tryGetAttachment(CommandContext ctx) {
-        final Attachment attachment = ctx.getMessage().getAttachments().get(0);
+        final Attachment attachment = ctx.getMessage().getAttachments().getFirst();
 
         try (attachment) {
             final File file = new File(attachment.getFileName());
@@ -200,7 +200,7 @@ protected String[] splitString(CommandContext ctx) {
             return null;
         }
 
-        if ("".equals(split[0].trim()) || "".equals(split[1].trim())) {
+        if (split[0].isBlank() || split[1].isBlank()) {
             sendMsg(ctx, "Missing arguments, check `" + ctx.getPrefix() + "help " + getName() + '`');
             return null;
         }

bot/src/main/java/me/duncte123/skybot/database/RedisConnection.java

@@ -44,6 +44,7 @@ public RedisConnection() {
         connect();
     }
 
+    @SuppressWarnings("PMD.AvoidThrowingRawExceptionTypes")
     private void connect() {
         if (!canConnect) {
             throw new RuntimeException("Shutdown method was called, new connection not allowed");

bot/src/main/java/me/duncte123/skybot/listeners/GuildMemberListener.java

@@ -164,7 +164,7 @@ private void onGuildMemberRemove(GuildMemberRemoveEvent event) {
 
         final Guild guild = event.getGuild();
         final long guildId = guild.getIdLong();
-        final GuildMemberInfo guildCounts = GuildUtils.GUILD_MEMBER_COUNTS.getIfPresent(guildId);
+        final GuildMemberInfo guildCounts = GuildUtils.GUILD_MEMBER_COUNTS.get(guildId);
 
         if (guildCounts != null) {
             if (user.isBot()) {
@@ -327,7 +327,7 @@ private void logMemberNotification(User user, Guild guild, String titlePart, Str
     }
 
     private void updateGuildCount(GuildMemberJoinEvent event, Guild guild) {
-        final GuildMemberInfo guildCounts = GuildUtils.GUILD_MEMBER_COUNTS.getIfPresent(guild.getIdLong());
+        final GuildMemberInfo guildCounts = GuildUtils.GUILD_MEMBER_COUNTS.get(guild.getIdLong());
 
         if (guildCounts != null) {
             final User user = event.getUser();

bot/src/main/java/me/duncte123/skybot/listeners/MessageListener.java

@@ -384,6 +384,7 @@ private void handleMessageEventChecked(String raw, Guild guild, MessageReceivedE
         }
     }
 
+    @SuppressWarnings("PMD.SimplifyBooleanReturns")
     private boolean doesNotStartWithPrefix(long selfId, String raw, String customPrefix) {
         final String rwLower = raw.toLowerCase();
 
@@ -418,11 +419,7 @@ private boolean hasCorrectCategory(@Nonnull String raw, @Nonnull String category
             getCommandName(customPrefix, raw).toLowerCase()
         );
 
-        if (command == null) {
-            return false;
-        }
-
-        return command.getCategory() == CommandCategory.valueOf(categoryName.toUpperCase());
+        return command == null || command.getCategory() == CommandCategory.valueOf(categoryName.toUpperCase());
     }
 
     @SuppressWarnings("ConstantConditions")

bot/src/main/java/me/duncte123/skybot/objects/command/Command.java

@@ -182,15 +182,7 @@ public String toString() {
 
     @Override
     public boolean equals(Object obj) {
-        if (obj == null) {
-            return false;
-        }
-
-        if (!(obj instanceof final Command command)) {
-            return false;
-        }
-
-        return this.name.equals(command.getName());
+        return (obj instanceof final Command command) && this.name.equals(command.getName());
     }
 
     private String getCooldownKey(CommandContext ctx) {

bot/src/main/java/me/duncte123/skybot/objects/command/CommandContext.java

@@ -217,11 +217,7 @@ public long getSendId() {
     }
 
     public boolean isChannelNSFW() {
-        if (getChannel() instanceof IAgeRestrictedChannel channel) {
-            return channel.isNSFW();
-        }
-
-        return false;
+        return (getChannel() instanceof IAgeRestrictedChannel channel) && channel.isNSFW();
     }
 
     // --------------- Methods that are in the GuildMessageReceivedEvent --------------- //

bot/src/main/java/me/duncte123/skybot/objects/user/FakeUser.java

@@ -88,7 +88,7 @@ public String getDefaultAvatarId() {
     @Nonnull
     @Override
     public String getDefaultAvatarUrl() {
-        return String.format(User.DEFAULT_AVATAR_URL, getDefaultAvatarId());
+        return String.format(DEFAULT_AVATAR_URL, getDefaultAvatarId());
     }
 
     @Nonnull

bot/src/main/java/me/duncte123/skybot/utils/AudioUtils.java

@@ -118,8 +118,8 @@ public TLongObjectMap<GuildMusicManager> getMusicManagers() {
 
     public static String getTimestamp(long milliseconds) {
         final int seconds = (int) (milliseconds / 1000) % 60;
-        final int minutes = (int) ((milliseconds / (1000 * 60)) % 60);
-        final int hours = (int) ((milliseconds / (1000 * 60 * 60)) % 24);
+        final int minutes = (int) (milliseconds / (1000 * 60)) % 60;
+        final int hours = (int) (milliseconds / (1000 * 60 * 60)) % 24;
 
         if (hours > 0) {
             return String.format("%02d:%02d:%02d", hours, minutes, seconds);

bot/src/main/java/me/duncte123/skybot/utils/GuildUtils.java

@@ -20,7 +20,6 @@
 
 import io.sentry.Sentry;
 import me.duncte123.skybot.database.AbstractDatabase;
-import me.duncte123.skybot.objects.DBMap;
 import me.duncte123.skybot.objects.GuildMemberInfo;
 import net.dv8tion.jda.api.entities.Guild;
 import net.dv8tion.jda.api.entities.Guild.VerificationLevel;
@@ -33,15 +32,16 @@
 
 import javax.annotation.Nonnull;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 
 public class GuildUtils {
-    public static final DBMap<Long, GuildMemberInfo> GUILD_MEMBER_COUNTS = new DBMap<>(ExpiringMap.builder()
+    public static final Map<Long, GuildMemberInfo> GUILD_MEMBER_COUNTS = ExpiringMap.builder()
         .expirationPolicy(ExpirationPolicy.ACCESSED)
         .expiration(1, TimeUnit.HOURS)
-        .build());
+        .build();
     private static final Logger LOGGER = LoggerFactory.getLogger(GuildUtils.class);
 
     private GuildUtils() {}
@@ -73,7 +73,7 @@ public static long[] getBotAndUserCount(Guild guild) {
             }
         }
 
-        final GuildMemberInfo guildCount = GUILD_MEMBER_COUNTS.getIfPresent(guild.getIdLong());
+        final GuildMemberInfo guildCount = GUILD_MEMBER_COUNTS.get(guild.getIdLong());
 
         // This should never happen
         if (guildCount == null) {
@@ -105,10 +105,10 @@ public static double[] getBotRatio(Guild guild) {
         final double botCount = counts[1];
 
         //percent in users
-        final double userCountP = (userCount / totalCount) * 100;
+        final double userCountP = userCount / totalCount * 100;
 
         //percent in bots
-        final double botCountP = (botCount / totalCount) * 100;
+        final double botCountP = botCount / totalCount * 100;
 
         LOGGER.debug("In the guild {}({} Members), {}% are users, {}% are bots",
             guild.getName(),
@@ -125,7 +125,7 @@ public static double[] getBotRatio(Guild guild) {
     }
 
     public static long getNitroUserCountCache(Guild guild) {
-        final GuildMemberInfo guildCount = GUILD_MEMBER_COUNTS.getIfPresent(guild.getIdLong());
+        final GuildMemberInfo guildCount = GUILD_MEMBER_COUNTS.get(guild.getIdLong());
 
         // This should never happen
         if (guildCount == null) {

bot/src/main/java/me/duncte123/skybot/utils/PerspectiveApi.java

@@ -56,7 +56,9 @@ public static float checkSwearFilter(String text, String channelId, String apiKe
                     return 0f;
                 }
 
-                throw new HttpException("Error while handling perspective api request: " + json);
+                Sentry.captureException(new HttpException("Error while handling perspective api request: " + json));
+
+                return 0f;
             }
 
             final JsonNode score = json.get("attributeScores")
@@ -67,7 +69,6 @@ public static float checkSwearFilter(String text, String channelId, String apiKe
         }
         catch (Exception e) {
             Sentry.captureException(e);
-            e.printStackTrace();
 
             return 0f;
         }