Switched Java to 21, fixed JavaDoc warnings.

gson/src/main/java/de/neitzel/gson/adapter/InstantTypeAdapter.java

@@ -24,6 +24,17 @@ import java.time.format.DateTimeParseException;
  */
 public class InstantTypeAdapter implements JsonSerializer<Instant>, JsonDeserializer<Instant> {
 
+    /**
+     * Constructs a new {@code InstantTypeAdapter} instance.
+     * <p>
+     * This is a default, no-argument constructor for the {@link InstantTypeAdapter} class,
+     * which provides custom (de)serialization support for {@link Instant} objects in
+     * accordance with the ISO-8601 standard.
+     */
+    public InstantTypeAdapter() {
+        // Default constructor
+    }
+
     /**
      * Serializes an {@link Instant} object into its ISO-8601 string representation as a {@link JsonElement}.
      *

gson/src/main/java/de/neitzel/gson/config/JsonConfiguration.java

@@ -21,7 +21,6 @@ import java.util.Map;
  */
 @Builder(builderClassName = "ConfigurationBuilder")
 public class JsonConfiguration {
-
     /**
      * The name of the application.
      * This variable is used to identify the application and is incorporated into various configurations,
@@ -67,6 +66,21 @@ public class JsonConfiguration {
      */
     private final Gson gson;
 
+    /**
+     * Constructs a new {@code JsonConfiguration} instance with the specified parameters.
+     *
+     * @param appName  the name of the application
+     * @param homeDir  the home directory path for the application
+     * @param settings a map containing configuration settings as key-value pairs
+     * @param gson     the Gson instance used for JSON serialization and deserialization
+     */
+    public JsonConfiguration(String appName, String homeDir, Map<String, String> settings, Gson gson) {
+        this.appName = appName;
+        this.homeDir = homeDir;
+        this.settings = settings;
+        this.gson = gson;
+    }
+
     /**
      * Stores a key-value pair into the configuration settings.
      * The value is serialized into a JSON string before being stored.
@@ -206,6 +220,18 @@ public class JsonConfiguration {
          */
         private String homeDir = System.getProperty("user.home");
 
+        /**
+         * Default constructor for the {@code JsonConfigurationBuilder} class.
+         * Initializes a new instance of the {@code JsonConfigurationBuilder}.
+         * This constructor allows creation of a builder used for configuring
+         * {@code JsonConfiguration} instances, enabling the specification of
+         * application-specific settings such as the application name, home directory,
+         * and custom Gson adapters.
+         */
+        public JsonConfigurationBuilder() {
+            // Default constructor
+        }
+
         /**
          * Sets the application name to be used in the configuration.
          *

net/src/main/java/de/neitzel/net/imap/ImapAccount.java

@@ -45,6 +45,8 @@ public class ImapAccount {
 
     /**
      * Retrieves the server address associated with this IMAP
+     *
+     * @return the server address as a String.
      */
     public String getServer() {
         return server;

pom.xml

@@ -23,12 +23,12 @@
     </modules>
 
     <properties>
-        <java.version>25</java.version>
+        <java.version>21</java.version>
         <required.maven.version>3.8.6</required.maven.version>
 
         <!-- Dependency versions -->
         <jakarta-inject-api>2.0.1</jakarta-inject-api>
-        <javafx.version>25.0.1</javafx.version>
+        <javafx.version>21.0.7</javafx.version>
         <jetbrains.annotations.version>26.0.2</jetbrains.annotations.version>
         <junit.version>6.0.1</junit.version>
         <lombok.version>1.18.42</lombok.version>

quarkus/src/main/java/de/neitzel/quarkus/util/GlobalRouteLogging.java

@@ -11,6 +11,17 @@ import lombok.extern.slf4j.Slf4j;
 @Slf4j
 public class GlobalRouteLogging {
 
+    /**
+     * Constructs a new {@code GlobalRouteLogging} instance.
+     * <p>
+     * This is a default, no-argument constructor for the {@link GlobalRouteLogging} class,
+     * which provides global logging functionality for all incoming routes in a Quarkus
+     * application using Vert.x Web.
+     */
+    public GlobalRouteLogging() {
+        // Default constructor
+    }
+
     /**
      * Logs all details of the incoming route request, including the method and URI, as well as all headers present in the request.
      * This method is designed to be used within a Vert.x Web application to log details for every incoming route globally.

quarkus/src/main/java/de/neitzel/quarkus/util/IncomingRequestFilter.java

@@ -22,6 +22,16 @@ import lombok.extern.slf4j.Slf4j;
 @Priority(Priorities.USER)
 public class IncomingRequestFilter implements ContainerRequestFilter {
 
+    /**
+     * Constructs a new {@code IncomingRequestFilter} instance.
+     * <p>
+     * This is a default, no-argument constructor for the {@link IncomingRequestFilter} class,
+     * which provides logging functionality for incoming HTTP requests in a JAX-RS application.
+     */
+    public IncomingRequestFilter() {
+        // Default constructor
+    }
+
     /**
      * Logs the details of incoming HTTP requests before they are processed by the application.
      * This includes logging the request method and URI, as well as all headers present in the request.

quarkus/src/main/java/de/neitzel/quarkus/util/LoggingRequestFilter.java

@@ -11,6 +11,17 @@ import lombok.extern.slf4j.Slf4j;
 @Slf4j
 @Provider
 public class LoggingRequestFilter implements ClientRequestFilter {
+
+    /**
+     * Constructs a new {@code LoggingRequestFilter} instance.
+     * <p>
+     * This is a default, no-argument constructor for the {@link LoggingRequestFilter} class,
+     * which provides logging functionality for outgoing HTTP requests in a JAX-RS client application.
+     */
+    public LoggingRequestFilter() {
+        // Default constructor
+    }
+    
     /**
      * Logs the details of HTTP requests before they are sent.
      *