Fix some Javadoc warnings in Java 21 (#12295)

Signed-off-by: Jakub Scholz <www@scholzj.com>

Author: scholzj

.checkstyle/checkstyle.xml

@@ -164,6 +164,7 @@
         <module name="JavadocMissingLeadingAsterisk" />
         <module name="JavadocMissingWhitespaceAfterAsterisk" />
         <module name="JavadocStyle">
+            <property name="checkEmptyJavadoc" value="true"/>
             <property name="checkFirstSentence" value="false"/>
         </module>
         <module name="NonEmptyAtclauseDescription"/>

.checkstyle/suppressions.xml

@@ -40,6 +40,7 @@
     <suppress checks="(JavadocMethod|JavadocType|JavadocVariable|MissingJavadocType|MissingJavadocMethod)" files="api[/\\]src[/\\]main[/\\]java[/\\]io[/\\]strimzi[/\\].*"/>
 
     <!-- The systemtest module is currently not ready or Javadoc checks-->
-    <suppress checks="(JavadocMethod|JavadocType|JavadocVariable|MissingJavadocType|MissingJavadocMethod)" files="systemtest[/\\]src[/\\]main[/\\]java[/\\]io[/\\]strimzi[/\\].*"/>
+    <suppress checks="(JavadocMethod|JavadocType|JavadocVariable|MissingJavadocType|MissingJavadocMethod|JavadocStyle)" files="systemtest[/\\]src[/\\]main[/\\]java[/\\]io[/\\]strimzi[/\\].*"/>
+    <suppress checks="(JavadocStyle)" files="systemtest[/\\]src[/\\]test[/\\]java[/\\]io[/\\]strimzi[/\\].*"/>
 
 </suppressions>

api/src/main/java/io/strimzi/api/kafka/model/connector/AbstractConnectorSpec.java

@@ -50,6 +50,8 @@ public abstract class AbstractConnectorSpec extends Spec {
     private AlterOffsets alterOffsets;
 
     /**
+     * Gets the maximum number of tasks.
+     *
      * @return  Max number of tasks
      */
     @Description("The maximum number of tasks for the Kafka Connector")
@@ -68,6 +70,8 @@ public void setTasksMax(Integer tasksMax) {
     }
 
     /**
+     * Gets the version or version range for the Kafka Connector.
+     *
      * @return Version or version range for the Kafka Connector
      */
     @Description("Desired version or version range to respect when starting the Kafka Connector. This is only supported when using Kafka Connect version 4.1.0 and higher.")
@@ -86,6 +90,8 @@ public void setVersion(String version) {
     }
 
     /**
+     * Gets the Kafka Connector configuration.
+     *
      * @return  Connector configuration
      */
     @Description("The Kafka Connector configuration. The following properties cannot be set: " + FORBIDDEN_PARAMETERS)
@@ -104,6 +110,8 @@ public void setConfig(Map<String, Object> config) {
     }
 
     /**
+     * Gets the flag indicating whether the connector should be paused.
+     *
      * @return  Flag indicating whether the connector should paused or not
      */
     @Description("Whether the connector should be paused. Defaults to false.")
@@ -125,6 +133,8 @@ public void setPause(Boolean pause) {
     }
 
     /**
+     * Gets the auto-restart configuration of this connector.
+     *
      * @return  Auto-restart configuration of this connector
      */
     @Description("Automatic restart of connector and tasks configuration")
@@ -143,6 +153,8 @@ public void setAutoRestart(AutoRestart autoRestart) {
     }
 
     /**
+     * Gets the state of the connector.
+     *
      * @return The state of the connector
      */
     @Description("The state the connector should be in. Defaults to running.")
@@ -160,6 +172,8 @@ public void setState(ConnectorState state) {
     }
 
     /**
+     * Gets the listOffsets configuration.
+     *
      * @return The listOffsets configuration.
      */
     @Description("Configuration for listing offsets")
@@ -177,6 +191,8 @@ public void setListOffsets(ListOffsets listOffsets) {
     }
 
     /**
+     * Gets the alterOffsets configuration.
+     *
      * @return The alterOffsets configuration.
      */
     @Description("Configuration for altering offsets")

api/src/main/java/io/strimzi/platform/PlatformFeatures.java

@@ -9,11 +9,15 @@
  */
 public interface PlatformFeatures {
     /**
+     * Gets the Kubernetes version on which Strimzi is running.
+     *
      * @return Returns the Kubernetes version on which Strimzi is running.
      */
     KubernetesVersion getKubernetesVersion();
 
     /**
+     * Checks if the cluster is OpenShift.
+     *
      * @return Returns true if the cluster Strimzi is running on was identified as OpenShift and false otherwise.
      */
     boolean isOpenshift();

certificate-manager/src/main/java/io/strimzi/certs/CertAndKey.java

@@ -45,69 +45,89 @@ public CertAndKey(byte[] key, byte[] cert, byte[] trustStore, byte[] keyStore, S
     }
 
     /**
+     * Gets the key as a byte array.
+     *
      * @return The key as a byte array
      */
     public byte[] key() {
         return key;
     }
 
     /**
+     * Gets the key as a base64 encoded String.
+     *
      * @return  The key as base64 encoded String
      */
     public String keyAsBase64String() {
         return Base64.getEncoder().encodeToString(key());
     }
 
     /**
+     * Gets the certificate as a byte array.
+     *
      * @return  The cert as a byte array
      */
     public byte[] cert() {
         return cert;
     }
 
     /**
+     * Gets the certificate as a base64 encoded String.
+     *
      * @return  The cert as base64 encoded String
      */
     public String certAsBase64String() {
         return Base64.getEncoder().encodeToString(cert());
     }
 
     /**
+     * Gets the truststore as a byte array.
+     *
      * @return  The truststore as a byte array
      */
     public byte[] trustStore() {
         return trustStore;
     }
 
     /**
+     * Gets the truststore as a base64 encoded String.
+     *
      * @return  The truststore as base64 encoded String
      */
     public String trustStoreAsBase64String() {
         return Base64.getEncoder().encodeToString(trustStore());
     }
 
     /**
+     * Gets the keystore as a byte array.
+     *
      * @return  The keystore as a byte array
      */
     public byte[] keyStore() {
         return keyStore;
     }
 
     /**
+     * Gets the keystore as a base64 encoded String.
+     *
      * @return  The keystore as base64 encoded String
      */
     public String keyStoreAsBase64String() {
         return Base64.getEncoder().encodeToString(keyStore());
     }
 
     /**
+     * Gets the store password.
+     *
      * @return  The store password
      */
     public String storePassword() {
         return storePassword;
     }
 
     /**
+     * Gets the store password as a base64 encoded String.
+     *
      * @return  The store password as base64 encoded String
      */
     public String storePasswordAsBase64String() {

certificate-manager/src/main/java/io/strimzi/certs/Subject.java

@@ -116,6 +116,8 @@ public Subject.Builder addIpAddress(String ip) {
         }
 
         /**
+         * Builds and returns a new Subject instance based on this builder configuration.
+         *
          * @return  Instance of the Subject class created based on this builder
          */
         public Subject build() {
@@ -142,6 +144,8 @@ private Subject(
     }
 
     /**
+     * Gets the organization name.
+     *
      * @return  Organization name
      */
     @JsonProperty
@@ -150,6 +154,8 @@ public String organizationName() {
     }
 
     /**
+     * Gets the common name.
+     *
      * @return  Common name
      */
     @JsonProperty
@@ -158,6 +164,8 @@ public String commonName() {
     }
 
     /**
+     * Gets the X500Principal based on this subject.
+     *
      * @return  X500Principal based on this subject
      */
     public X500Principal principal() {
@@ -177,6 +185,8 @@ public X500Principal principal() {
     }
 
     /**
+     * Gets the set of DNS names.
+     *
      * @return  Set of DNS names
      */
     @JsonProperty
@@ -185,6 +195,8 @@ public Set<String> dnsNames() {
     }
 
     /**
+     * Gets the set of IP addresses.
+     *
      * @return  Set of IP addresses
      */
     @JsonProperty
@@ -219,6 +231,8 @@ public String toString() {
     }
 
     /**
+     * Gets the map with the Subject Alternative Names (SANs).
+     *
      * @return  Map with the SANs
      */
     public Map<String, String> subjectAltNames() {
@@ -235,13 +249,17 @@ public Map<String, String> subjectAltNames() {
     }
 
     /**
+     * Checks if any SANs are present in this subject.
+     *
      * @return  True if any SANs are present. False otherwise.
      */
     public boolean hasSubjectAltNames() {
         return !dnsNames().isEmpty() || !ipAddresses().isEmpty();
     }
 
     /**
+     * Gets the Distinguished Name (DN) in the format understood by OpenSSL.
+     *
      * @return The DN in the format understood by {@code openssl}.
      */
     public String opensslDn() {