According to NodeTypeManager, this is a code sample to create node type:
    import javax.jcr.PropertyType;
    import javax.jcr.Session;
    import javax.jcr.nodetype.NodeType;
    import javax.jcr.nodetype.NodeTypeManager;
    import javax.jcr.nodetype.NodeTypeTemplate;
    import javax.jcr.nodetype.PropertyDefinitionTemplate;
    /**
     *
     * @author Aroniaina
     */
    public class FileType {
        public static void RegisterFileType(Session session) throws Exception {        
            NodeTypeManager nodeTypeManager = session.getWorkspace().getNodeTypeManager();
            NodeTypeTemplate nodeType = nodeTypeManager.createNodeTypeTemplate();
            nodeType.setName("FileType");
            String[] str = {"nt:resource"};        
            nodeType.setDeclaredSuperTypeNames(str);
            nodeType.setMixin(false);
            nodeType.setQueryable(true);
            PropertyDefinitionTemplate path = nodeTypeManager.createPropertyDefinitionTemplate();
            path.setName("jcr:path");
            path.setRequiredType(PropertyType.PATH);
            path.setQueryOrderable(false);
            path.setFullTextSearchable(false);
            nodeType.getPropertyDefinitionTemplates().add(path);
            PropertyDefinitionTemplate nom = nodeTypeManager.createPropertyDefinitionTemplate();
            nom.setName("jcr:nom");
            nom.setRequiredType(PropertyType.STRING);
            nom.setQueryOrderable(true);
            nom.setFullTextSearchable(true);
            nodeType.getPropertyDefinitionTemplates().add(nom);
            PropertyDefinitionTemplate description = nodeTypeManager.createPropertyDefinitionTemplate();
            description.setName("jcr:description");
            description.setRequiredType(PropertyType.STRING);
            description.setQueryOrderable(true);
            description.setFullTextSearchable(true);
            nodeType.getPropertyDefinitionTemplates().add(description);
            PropertyDefinitionTemplate motsCles = nodeTypeManager.createPropertyDefinitionTemplate();
            motsCles.setName("jcr:motsCles");
            motsCles.setRequiredType(PropertyType.STRING);
            motsCles.setQueryOrderable(true);
            motsCles.setFullTextSearchable(true);
            nodeType.getPropertyDefinitionTemplates().add(motsCles);
            PropertyDefinitionTemplate size = nodeTypeManager.createPropertyDefinitionTemplate();
            size.setName("jcr:size");
            size.setRequiredType(PropertyType.STRING);
            size.setQueryOrderable(true);
            size.setFullTextSearchable(false);
            nodeType.getPropertyDefinitionTemplates().add(size);
            PropertyDefinitionTemplate users = nodeTypeManager.createPropertyDefinitionTemplate();
            users.setName("jcr:users");
            users.setRequiredType(PropertyType.STRING);
            users.setQueryOrderable(true);
            users.setFullTextSearchable(false);
            nodeType.getPropertyDefinitionTemplates().add(users);
            PropertyDefinitionTemplate groupe = nodeTypeManager.createPropertyDefinitionTemplate();
            groupe.setName("jcr:groupe");
            groupe.setRequiredType(PropertyType.STRING);
            groupe.setQueryOrderable(true);
            groupe.setFullTextSearchable(false);
            nodeType.getPropertyDefinitionTemplates().add(groupe);
            NodeType newnodetype = nodeTypeManager.registerNodeType(nodeType, true);             
            session.save();        
        }
    }