diff --git a/base-api-client/pom.xml b/base-api-client/pom.xml
index dab0096f0..d6fafb2ac 100644
--- a/base-api-client/pom.xml
+++ b/base-api-client/pom.xml
@@ -6,7 +6,7 @@
 	<parent>
 		<groupId>com.cloudesire.platform</groupId>
 		<artifactId>cloudesire-api-client-root</artifactId>
-		<version>3.9.1-SNAPSHOT</version>
+		<version>4.0.0-SNAPSHOT</version>
 	</parent>
 
 	<artifactId>base-api-client</artifactId>
@@ -20,7 +20,7 @@
 		<dependency>
 			<groupId>com.cloudesire.platform</groupId>
 			<artifactId>common-dto</artifactId>
-			<version>3.9.1-SNAPSHOT</version>
+			<version>4.0.0-SNAPSHOT</version>
 		</dependency>
 		<dependency>
 			<groupId>com.squareup.retrofit2</groupId>
diff --git a/cloudesire-api-client-dto/pom.xml b/cloudesire-api-client-dto/pom.xml
index bebfdfff2..01d528f15 100644
--- a/cloudesire-api-client-dto/pom.xml
+++ b/cloudesire-api-client-dto/pom.xml
@@ -4,7 +4,7 @@
 	<parent>
 		<groupId>com.cloudesire.platform</groupId>
 		<artifactId>cloudesire-api-client-root</artifactId>
-		<version>3.9.1-SNAPSHOT</version>
+		<version>4.0.0-SNAPSHOT</version>
 	</parent>
 
 	<artifactId>cloudesire-api-client-dto</artifactId>
@@ -17,7 +17,7 @@
 		<dependency>
 			<groupId>com.cloudesire.platform</groupId>
 			<artifactId>base-api-client</artifactId>
-			<version>3.9.1-SNAPSHOT</version>
+			<version>4.0.0-SNAPSHOT</version>
 		</dependency>
 		<dependency>
 			<groupId>org.hibernate.validator</groupId>
diff --git a/cloudesire-api-client-dto/src/main/java/com/cloudesire/platform/apiclient/dto/model/dto/EnvironmentDTO.java b/cloudesire-api-client-dto/src/main/java/com/cloudesire/platform/apiclient/dto/model/dto/EnvironmentDTO.java
index 9fda3d87f..2d8e700c8 100644
--- a/cloudesire-api-client-dto/src/main/java/com/cloudesire/platform/apiclient/dto/model/dto/EnvironmentDTO.java
+++ b/cloudesire-api-client-dto/src/main/java/com/cloudesire/platform/apiclient/dto/model/dto/EnvironmentDTO.java
@@ -1526,19 +1526,19 @@ public SelfBilling getSelfBilling()
         public void setSelfBilling( Object selfBilling )
         {
             /* @deprecated */
-            if ( selfBilling instanceof Boolean && (Boolean) selfBilling )
+            if ( selfBilling instanceof Boolean bSelfBilling && bSelfBilling )
             {
                 this.selfBilling = SelfBilling.PER_PLAN;
             }
 
-            if ( selfBilling instanceof String )
+            if ( selfBilling instanceof String sSelfBilling )
             {
-                this.selfBilling = SelfBilling.valueOf( (String) selfBilling );
+                this.selfBilling = SelfBilling.valueOf( sSelfBilling );
             }
 
-            if ( selfBilling instanceof SelfBilling )
+            if ( selfBilling instanceof SelfBilling oSelfBilling )
             {
-                this.selfBilling = (SelfBilling) selfBilling;
+                this.selfBilling = oSelfBilling;
             }
         }
 
diff --git a/cloudesire-api-client-dto/src/main/java/com/cloudesire/platform/apiclient/dto/model/dto/MailEnvironmentDTO.java b/cloudesire-api-client-dto/src/main/java/com/cloudesire/platform/apiclient/dto/model/dto/MailEnvironmentDTO.java
index dc8e7e629..fcbb5c94f 100644
--- a/cloudesire-api-client-dto/src/main/java/com/cloudesire/platform/apiclient/dto/model/dto/MailEnvironmentDTO.java
+++ b/cloudesire-api-client-dto/src/main/java/com/cloudesire/platform/apiclient/dto/model/dto/MailEnvironmentDTO.java
@@ -367,8 +367,7 @@ public MailConfiguration getCouponConfiguration( CouponType couponType )
                     return getDiscountCoupon();
                 case FIXED_PRICE:
                     return getFixedPriceCoupon();
-                case TRIAL:
-                case EXTENDED_TRIAL:
+                case TRIAL, EXTENDED_TRIAL:
                     return getTrialCoupon();
                 default:
                     return null;
diff --git a/cloudesire-api-client/pom.xml b/cloudesire-api-client/pom.xml
index 1e89602ea..355f4aa59 100644
--- a/cloudesire-api-client/pom.xml
+++ b/cloudesire-api-client/pom.xml
@@ -6,7 +6,7 @@
 	<parent>
 		<groupId>com.cloudesire.platform</groupId>
 		<artifactId>cloudesire-api-client-root</artifactId>
-		<version>3.9.1-SNAPSHOT</version>
+		<version>4.0.0-SNAPSHOT</version>
 	</parent>
 
 	<artifactId>cloudesire-api-client</artifactId>
@@ -15,12 +15,12 @@
 		<dependency>
 			<groupId>com.cloudesire.platform</groupId>
 			<artifactId>base-api-client</artifactId>
-			<version>3.9.1-SNAPSHOT</version>
+			<version>4.0.0-SNAPSHOT</version>
 		</dependency>
 		<dependency>
 			<groupId>com.cloudesire.platform</groupId>
 			<artifactId>cloudesire-api-client-dto</artifactId>
-			<version>3.9.1-SNAPSHOT</version>
+			<version>4.0.0-SNAPSHOT</version>
 		</dependency>
 		<dependency>
 			<groupId>ch.qos.logback</groupId>
diff --git a/common-dto/pom.xml b/common-dto/pom.xml
index 4099142f1..892bf6080 100644
--- a/common-dto/pom.xml
+++ b/common-dto/pom.xml
@@ -5,7 +5,7 @@
 	<parent>
 		<groupId>com.cloudesire.platform</groupId>
 		<artifactId>cloudesire-api-client-root</artifactId>
-		<version>3.9.1-SNAPSHOT</version>
+		<version>4.0.0-SNAPSHOT</version>
 	</parent>
 
 	<artifactId>common-dto</artifactId>
diff --git a/common-dto/src/main/java/com/liberologico/cloudesire/common/validators/ApplicationFileURLValidator.java b/common-dto/src/main/java/com/liberologico/cloudesire/common/validators/ApplicationFileURLValidator.java
index e0ec40854..8777c633b 100644
--- a/common-dto/src/main/java/com/liberologico/cloudesire/common/validators/ApplicationFileURLValidator.java
+++ b/common-dto/src/main/java/com/liberologico/cloudesire/common/validators/ApplicationFileURLValidator.java
@@ -4,6 +4,7 @@
 
 import jakarta.validation.ConstraintValidator;
 import jakarta.validation.ConstraintValidatorContext;
+
 import java.net.MalformedURLException;
 import java.net.URL;
 
@@ -17,7 +18,7 @@ public void initialize( ApplicationFileURL constraintAnnotation )
 
     public boolean isValid( CharSequence value, ConstraintValidatorContext constraintValidatorContext )
     {
-        if ( value == null || value.length() == 0 ) return true;
+        if ( value == null || value.isEmpty() ) return true;
 
         if ( value.toString().startsWith( DockerConstants.SCHEMA ) )
         {
diff --git a/pom.xml b/pom.xml
index 70c87ed40..11ca8c4e6 100644
--- a/pom.xml
+++ b/pom.xml
@@ -8,16 +8,16 @@
 
 	<groupId>com.cloudesire.platform</groupId>
 	<artifactId>cloudesire-api-client-root</artifactId>
-	<version>3.9.1-SNAPSHOT</version>
+	<version>4.0.0-SNAPSHOT</version>
 
 	<name>cloudesire-api-client-root</name>
 	<description>Java API client for Cloudesire platform</description>
-	<url>http://github.com/cloudesire/java-api-client</url>
+	<url>https://github.com/cloudesire/java-api-client</url>
 
 	<scm>
 		<connection>scm:git:git@github.com:ClouDesire/java-api-client.git</connection>
 		<developerConnection>scm:git:git@github.com:ClouDesire/java-api-client.git</developerConnection>
-		<url>http://github.com/cloudesire/java-api-client/tree/master</url>
+		<url>https://github.com/cloudesire/java-api-client/tree/master</url>
 	</scm>
 
 	<modules>