diff --git a/md-jee-cdi/src/main/java/com/github/matschieu/jakartaee/cdi/AnnotationUtils.java b/md-jee-cdi/src/main/java/com/github/matschieu/jakartaee/cdi/AnnotationUtils.java
index 3284705..946d028 100644
--- a/md-jee-cdi/src/main/java/com/github/matschieu/jakartaee/cdi/AnnotationUtils.java
+++ b/md-jee-cdi/src/main/java/com/github/matschieu/jakartaee/cdi/AnnotationUtils.java
@@ -7,12 +7,7 @@ public final class AnnotationUtils {
 	private AnnotationUtils() { }
 
 	public static final Annotation toAnnotation(Class<? extends Annotation> annotationType) {
-		return new Annotation() {
-			@Override
-			public Class<? extends Annotation> annotationType() {
-				return annotationType;
-			}
-		};
+		return () -> annotationType;
 	}
 
 }
diff --git a/md-jee-cdi/src/main/java/com/github/matschieu/jakartaee/cdi/primitive/NumberProducer.java b/md-jee-cdi/src/main/java/com/github/matschieu/jakartaee/cdi/primitive/NumberProducer.java
index 91f5131..314ccc3 100644
--- a/md-jee-cdi/src/main/java/com/github/matschieu/jakartaee/cdi/primitive/NumberProducer.java
+++ b/md-jee-cdi/src/main/java/com/github/matschieu/jakartaee/cdi/primitive/NumberProducer.java
@@ -4,12 +4,14 @@
 
 public class NumberProducer {
 
+	private static final java.util.Random RANDOM = new java.util.Random();
+
 	// A producer can be a field
 	// It must be a default-access, public, protected or private, field of a managed bean class.
 	// A producer field may be either static or non-static.
 	@Produces
 	@Null
-	private Integer nullInteger = null;
+	private final Integer nullInteger = null;
 
 	// A producer method must be a default-access, public, protected or private, non-abstract method of a managed bean class
 	// A producer method may be either static or non-static
@@ -17,14 +19,14 @@ public class NumberProducer {
 	@Produces
 	@Random
 	public Integer getRandomInteger() {
-		return Integer.valueOf((new java.util.Random()).nextInt());
+		return Integer.valueOf(RANDOM.nextInt());
 	}
 
 	// A producer can also return a primitive type
 	@Produces
 	@Random
 	public static double getRandomInt() {
-		return 1.0 * (new java.util.Random()).nextInt();
+		return 1.0 * RANDOM.nextInt();
 	}
 
 }
diff --git a/md-jee-interceptor/src/main/java/com/github/matschieu/jee/interceptor/dummy/IntIncrementInterceptor.java b/md-jee-interceptor/src/main/java/com/github/matschieu/jee/interceptor/dummy/IntIncrementInterceptor.java
index 02aaf46..d93b69b 100644
--- a/md-jee-interceptor/src/main/java/com/github/matschieu/jee/interceptor/dummy/IntIncrementInterceptor.java
+++ b/md-jee-interceptor/src/main/java/com/github/matschieu/jee/interceptor/dummy/IntIncrementInterceptor.java
@@ -11,8 +11,8 @@ public class IntIncrementInterceptor {
 	public Object interceptOrder(final InvocationContext ctx) throws Exception {
 		System.out.println(this.getClass().getSimpleName() + ": Intercept " + ctx.getMethod().getName());
 		final Object output = ctx.proceed();
-		if (output instanceof Integer) {
-			return ((Integer) output).intValue() + 1;
+		if (output instanceof final Integer integer) {
+			return integer.intValue() + 1;
 		}
 		return output;
 	}
diff --git a/md-jee-interceptor/src/main/java/com/github/matschieu/jee/interceptor/validation/ValidationInterceptor.java b/md-jee-interceptor/src/main/java/com/github/matschieu/jee/interceptor/validation/ValidationInterceptor.java
index 47bcd13..e6f091e 100644
--- a/md-jee-interceptor/src/main/java/com/github/matschieu/jee/interceptor/validation/ValidationInterceptor.java
+++ b/md-jee-interceptor/src/main/java/com/github/matschieu/jee/interceptor/validation/ValidationInterceptor.java
@@ -11,7 +11,7 @@
 @Interceptor
 public class ValidationInterceptor {
 
-	private void checkObject(final Object obj) throws Exception {
+	private void checkObject(final Object obj) throws IllegalArgumentException, IllegalAccessException, NullElementException {
 		if ((obj == null) || (obj instanceof String)) {
 			return;
 		}
@@ -27,7 +27,7 @@ private void checkObject(final Object obj) throws Exception {
 		}
 	}
 
-	private void checkFieldAnnotation(final String fieldName, final Annotation[] annotations, final Object value) throws Exception {
+	private void checkFieldAnnotation(final String fieldName, final Annotation[] annotations, final Object value) throws NullElementException {
 		for (final Annotation annotation : annotations) {
 			if (annotation.annotationType() == NotNullElement.class && value == null) {
 				throw new NullElementException(fieldName + " is null");
diff --git a/md-jee-interceptor/src/test/java/com/github/matschieu/jee/interceptor/dummy/MyServiceTest.java b/md-jee-interceptor/src/test/java/com/github/matschieu/jee/interceptor/dummy/MyServiceTest.java
index af88fb7..a8e4051 100644
--- a/md-jee-interceptor/src/test/java/com/github/matschieu/jee/interceptor/dummy/MyServiceTest.java
+++ b/md-jee-interceptor/src/test/java/com/github/matschieu/jee/interceptor/dummy/MyServiceTest.java
@@ -9,7 +9,7 @@
 import jakarta.inject.Inject;
 
 @EnableWeld
-public class MyServiceTest {
+class MyServiceTest {
 
 	@WeldSetup
 	public WeldInitiator weld = WeldInitiator.from(MyService.class, MyServiceImpl.class).build();
@@ -18,7 +18,7 @@ public class MyServiceTest {
 	private MyService myService;
 
 	@Test
-	public void testMyService() {
+	void testMyService() {
 		Assertions.assertEquals(2, this.myService.getInt());
 		Assertions.assertEquals(Integer.valueOf(2), this.myService.getInteger());
 		Assertions.assertEquals("{[MyString]}", this.myService.getString());
diff --git a/md-jee-interceptor/src/test/java/com/github/matschieu/jee/interceptor/validation/ResourceServiceTest.java b/md-jee-interceptor/src/test/java/com/github/matschieu/jee/interceptor/validation/ResourceServiceTest.java
index 08953ac..deb01bf 100644
--- a/md-jee-interceptor/src/test/java/com/github/matschieu/jee/interceptor/validation/ResourceServiceTest.java
+++ b/md-jee-interceptor/src/test/java/com/github/matschieu/jee/interceptor/validation/ResourceServiceTest.java
@@ -11,7 +11,7 @@
 import jakarta.inject.Inject;
 
 @EnableWeld
-public class ResourceServiceTest {
+class ResourceServiceTest {
 
 	@WeldSetup
 	public WeldInitiator weld = WeldInitiator.from(ResourceService.class, ResourceServiceImpl.class).build();
@@ -20,7 +20,7 @@ public class ResourceServiceTest {
 	private ResourceService resourceService;
 
 	@Test
-	public void testMyServiceCreateResource1() {
+	void testMyServiceCreateResource1() {
 		try {
 			this.resourceService.createResource(null, "", "");
 			fail();
@@ -41,7 +41,7 @@ public void testMyServiceCreateResource1() {
 	}
 
 	@Test
-	public void testMyServiceCreateResource2() {
+	void testMyServiceCreateResource2() {
 		try {
 			this.resourceService.createResource(new Resource(null, "", ""));
 			fail();
@@ -62,7 +62,7 @@ public void testMyServiceCreateResource2() {
 	}
 
 	@Test
-	public void testMyServiceGetResource() {
+	void testMyServiceGetResource() {
 		Resource resource;
 
 		try {
@@ -82,7 +82,7 @@ public void testMyServiceGetResource() {
 	}
 
 	@Test
-	public void testMyServiceDeleteResource() {
+	void testMyServiceDeleteResource() {
 		try {
 			this.resourceService.deleteResource(null);
 			fail();