BAEL-5123: Annotation Processor for Hibernate Validator (#11673)

* feat(wip): add Hibernate Validator AP example

* chore: change AP version to 6.2.0.Final

See https://hibernate.atlassian.net/browse/HV-1868

* revert(style): remove unnecessary formatter

See https://github.com/eugenp/tutorials/pull/11673#discussion_r784444016

* fix: remove unauthorised annotation

 The AP was triggering a compile time error because the annotation @NotBlank is disallowed for the Profile data type. That's why the CI was failing.

 This customer class is unrelated to the article being written.

* fix(style): revert indentation issue

See https://github.com/eugenp/tutorials/pull/11673/files#r788146422

javaxval/pom.xml

@@ -15,7 +15,7 @@
 
     <dependencies>
         <dependency>
-            <groupId>org.hibernate</groupId>
+            <groupId>org.hibernate.validator</groupId>
             <artifactId>hibernate-validator</artifactId>
             <version>${hibernate-validator.version}</version>
         </dependency>
@@ -36,8 +36,39 @@
         </dependency>
     </dependencies>
 
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>${maven.compiler.version}</version>
+                <configuration>
+                    <source>${maven.compiler.source}</source>
+                    <target>${maven.compiler.target}</target>
+                    <fork>true</fork>
+                    <compilerArgs>
+                        <arg>-Averbose=true</arg>
+                        <arg>-AmethodConstraintsSupported=true</arg>
+                        <arg>-AdiagnosticKind=ERROR</arg>
+                    </compilerArgs>
+                    <annotationProcessorPaths>
+                        <path>
+                            <groupId>org.hibernate.validator</groupId>
+                            <artifactId>hibernate-validator-annotation-processor</artifactId>
+                            <version>${hibernate-validator.ap.version}</version>
+                        </path>
+                    </annotationProcessorPaths>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
     <properties>
         <hibernate-validator.version>6.0.13.Final</hibernate-validator.version>
+        <hibernate-validator.ap.version>6.2.0.Final</hibernate-validator.ap.version>
+        <maven.compiler.version>3.6.1</maven.compiler.version>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
         <javax.el.version>3.0.0</javax.el.version>
         <org.springframework.version>5.0.2.RELEASE</org.springframework.version>
     </properties>

javaxval/src/main/java/com/baeldung/javaxval/container/validation/Customer.java

@@ -20,7 +20,6 @@ public class Customer {
     @PositiveOrZero
     private OptionalInt numberOfOrders;
 
-    @NotBlank
     private Profile profile;
 
     public String getName() {

javaxval/src/main/java/com/baeldung/javaxval/hibernate/validator/ap/Message.java

@@ -0,0 +1,95 @@
+package com.baeldung.javaxval.hibernate.validator.ap;
+
+import javax.validation.constraints.NotBlank;
+import javax.validation.constraints.NotNull;
+import javax.validation.constraints.Past;
+import java.util.List;
+import java.util.Optional;
+
+public class Message {
+
+    @NotNull(message = "Content cannot be null")
+    private String content;
+
+    private boolean isDelivered;
+
+    private List<@NotBlank String> recipients;
+
+    // uncomment in order to trigger AP annotation detection
+    // The annotation @Past is disallowed for this data type.
+    // @Past
+    private String createdAt;
+
+    public String getContent() {
+        return content;
+    }
+
+    public Message(String content, boolean isDelivered, List<@NotBlank String> recipients, String createdAt) {
+        this.content = content;
+        this.isDelivered = isDelivered;
+        this.recipients = recipients;
+        this.createdAt = createdAt;
+    }
+
+    // uncomment in order to trigger AP annotation detection
+    // The annotation @Min is disallowed for the return type of this method.
+    // @Min(3)
+    public boolean broadcast() {
+        // setup a logic
+        // to send to recipients
+        return true;
+    }
+
+    // uncomment in order to trigger AP annotation detection
+    // Void methods may not be annotated with constraint annotations.
+    // @NotNull
+    public void archive() {
+        // archive the message
+    }
+
+    // uncomment in order to trigger AP annotation detection
+    // Constraint annotations must not be specified at methods, which are no valid JavaBeans getter methods.
+    // NOTE: add <arg>-AmethodConstraintsSupported=false</arg> to compiler args before
+    // @AssertTrue
+    public boolean delete() {
+        // delete the message
+        return false;
+    }
+
+    public void setContent(String content) {
+        this.content = content;
+    }
+
+    public boolean isDelivered() {
+        return isDelivered;
+    }
+
+    public void setDelivered(boolean delivered) {
+        isDelivered = delivered;
+    }
+
+    public List<String> getRecipients() {
+        return recipients;
+    }
+
+    public void setRecipients(List<String> recipients) {
+        this.recipients = recipients;
+    }
+
+    public void setCreatedAt(String createdAt) {
+        this.createdAt = createdAt;
+    }
+
+    public String getName() {
+        return content;
+    }
+
+    public void setName(String content) {
+        this.content = content;
+    }
+
+    public Optional<@Past String> getCreatedAt() {
+        return Optional.ofNullable(createdAt);
+    }
+
+}