Use javax annotation for validation

Signed-off-by: SirWayne <dennis.melzer@bosch-si.com>

hawkbit-repository/src/main/java/org/eclipse/hawkbit/repository/TargetManagement.java

@@ -27,10 +27,8 @@ import javax.persistence.criteria.JoinType;
 import javax.persistence.criteria.Order;
 import javax.persistence.criteria.Predicate;
 import javax.persistence.criteria.Root;
-import javax.validation.ConstraintViolationException;
 import javax.validation.constraints.NotNull;
 
-import org.apache.commons.lang3.StringUtils;
 import org.eclipse.hawkbit.Constants;
 import org.eclipse.hawkbit.eventbus.event.TargetTagAssigmentResultEvent;
 import org.eclipse.hawkbit.executor.AfterTransactionCommitExecutor;
@@ -933,11 +931,6 @@ public class TargetManagement {
     public Target createTarget(@NotNull final Target target, @NotNull final TargetUpdateStatus status,
             final Long lastTargetQuery, final URI address) {
 
-        if (StringUtils.isEmpty(target.getControllerId())) {
-            throw new ConstraintViolationException("Empty string for controller id not allowed",
-                    Collections.emptySet());
-        }
-
         if (targetRepository.findByControllerId(target.getControllerId()) != null) {
             throw new EntityAlreadyExistsException(target.getControllerId());
         }

hawkbit-repository/src/main/java/org/eclipse/hawkbit/repository/model/Target.java

@@ -32,6 +32,8 @@ import javax.persistence.PrimaryKeyJoinColumn;
 import javax.persistence.Table;
 import javax.persistence.Transient;
 import javax.persistence.UniqueConstraint;
+import javax.validation.constraints.NotNull;
+import javax.validation.constraints.Size;
 
 import org.eclipse.hawkbit.im.authentication.SpPermission;
 import org.eclipse.hawkbit.repository.model.helper.SecurityChecker;
@@ -74,6 +76,8 @@ public class Target extends NamedEntity implements Persistable<Long> {
     private static final long serialVersionUID = 1L;
 
     @Column(name = "controller_id", length = 64)
+    @Size(min = 1)
+    @NotNull
     private String controllerId;
 
     @Transient

hawkbit-repository/src/test/java/org/eclipse/hawkbit/repository/TargetManagementTest.java

@@ -68,13 +68,20 @@ public class TargetManagementTest extends AbstractIntegrationTest {
 
     @Test
     @Description("Verify that a target with empty controller id cannot be created")
-    public void createTarget() {
+    public void createTargetWithNoControllerId() {
         try {
             targetManagement.createTarget(new Target(""));
             fail("target with empty controller id should not be created");
         } catch (final ConstraintViolationException e) {
             // ok
         }
+
+        try {
+            targetManagement.createTarget(new Target(null));
+            fail("target with empty controller id should not be created");
+        } catch (final ConstraintViolationException e) {
+            // ok
+        }
     }
 
     @Test