Java 11 compatibility

klab.engine.diff

diff --git a/klab.engine/src/main/java/org/integratedmodelling/klab/cli/commands/Who.java b/klab.engine/src/main/java/org/integratedmodelling/klab/cli/commands/Who.java
index fb5d33ede..242f56343 100644
--- a/klab.engine/src/main/java/org/integratedmodelling/klab/cli/commands/Who.java
+++ b/klab.engine/src/main/java/org/integratedmodelling/klab/cli/commands/Who.java
@@ -1,6 +1,7 @@
 package org.integratedmodelling.klab.cli.commands;
 
 import java.util.Map;
+import java.util.stream.Collectors;
 
 import org.integratedmodelling.kim.api.IServiceCall;
 import org.integratedmodelling.klab.Network;
@@ -19,7 +20,7 @@ public class Who implements ICommand {
 
 		String ret = "Session ID = " + session.getId() + "\n" + session.getUser().getUsername() + " ("
 				+ session.getUser().getEmailAddress() + ") "
-				+ session.getUser().getGroups().stream().map((g) -> g.getId()).toList();
+				+ session.getUser().getGroups().stream().map((g) -> g.getId()).collect(Collectors.toList());
 
 		if (nodeId != null) {
 			INodeIdentity node = Network.INSTANCE.getNode(nodeId);
diff --git a/klab.engine/src/main/java/org/integratedmodelling/klab/engine/runtime/Session.java b/klab.engine/src/main/java/org/integratedmodelling/klab/engine/runtime/Session.java
index 5f06f4bb7..ee9af2c36 100644
--- a/klab.engine/src/main/java/org/integratedmodelling/klab/engine/runtime/Session.java
+++ b/klab.engine/src/main/java/org/integratedmodelling/klab/engine/runtime/Session.java
@@ -170,6 +170,7 @@ import org.integratedmodelling.klab.utils.NameGenerator;
 import org.integratedmodelling.klab.utils.NotificationUtils;
 import org.integratedmodelling.klab.utils.Pair;
 import org.integratedmodelling.klab.utils.Parameters;
+import org.integratedmodelling.klab.utils.StringUtils;
 import org.springframework.security.core.GrantedAuthority;
 import org.springframework.security.core.authority.SimpleGrantedAuthority;
 import org.springframework.security.core.userdetails.UserDetails;
@@ -1026,7 +1027,7 @@ public class Session extends GroovyObjectSupport
 			code.append(token.getValue() + " ");
 		}
 		String cc = code.toString();
-		if (!cc.isBlank() && !cc.contains("?")) {
+		if (!StringUtils.isBlank(cc) && !cc.contains("?")) {
 			try {
 				IObservable observable = Observables.INSTANCE.declare(cc);
 				if (observable != null) {
diff --git a/klab.engine/src/main/java/org/integratedmodelling/klab/owl/syntax/SemanticExpression.java b/klab.engine/src/main/java/org/integratedmodelling/klab/owl/syntax/SemanticExpression.java
index 410931030..dc97a85bf 100644
--- a/klab.engine/src/main/java/org/integratedmodelling/klab/owl/syntax/SemanticExpression.java
+++ b/klab.engine/src/main/java/org/integratedmodelling/klab/owl/syntax/SemanticExpression.java
@@ -28,6 +28,7 @@ import org.integratedmodelling.klab.owl.Concept;
 import org.integratedmodelling.klab.owl.syntax.SemanticScope.Constraint;
 import org.integratedmodelling.klab.rest.StyledKimToken;
 import org.integratedmodelling.klab.utils.StringUtil;
+import org.integratedmodelling.klab.utils.StringUtils;
 import org.integratedmodelling.klab.utils.Utils;
 import org.jgrapht.Graph;
 import org.jgrapht.graph.DefaultDirectedGraph;
@@ -126,7 +127,7 @@ public class SemanticExpression {
 
         public IObservable buildObservable() {
             String declaration = buildDeclaration();
-            if (declaration.isBlank() || declaration.contains("?")) {
+            if (StringUtils.isBlank(declaration) || declaration.contains("?")) {
                 return null;
             }
             try {
diff --git a/klab.engine/src/main/java/org/integratedmodelling/klab/persistence/ModelKbox.java b/klab.engine/src/main/java/org/integratedmodelling/klab/persistence/ModelKbox.java
index 3e606816b..3d9f1a88c 100644
--- a/klab.engine/src/main/java/org/integratedmodelling/klab/persistence/ModelKbox.java
+++ b/klab.engine/src/main/java/org/integratedmodelling/klab/persistence/ModelKbox.java
@@ -9,6 +9,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.h2gis.utilities.SpatialResultSet;
 import org.integratedmodelling.kim.api.IKimConcept.Type;
@@ -272,7 +273,7 @@ public class ModelKbox extends ObservableKbox {
 		List<ModelReference> ret = new ArrayList<>();
 		IUserIdentity user = context.getSession().getParentIdentity(IUserIdentity.class);
 		Collection<IResolutionConstraint> constraints = context.getSession().getState().getResolutionConstraints();
-		Set<String> userPermissions = new HashSet<>(user.getGroups().stream().map((g) -> g.getId()).toList());
+		Set<String> userPermissions = new HashSet<>(user.getGroups().stream().map((g) -> g.getId()).collect(Collectors.toList()));
 
 		if (!database.hasTable("model")) {
 			return ret;