void (@NotNull Project project, @NotNull Sdk jdk) { ProjectRootManagerEx rootManager = ProjectRootManagerEx.getInstanceEx(project); rootManager.setProjectSdk(jdk); JavaSdkVersion version = JavaSdk.getInstance().getVersion(jdk); if (version != null) { LanguageLevel maxLevel = version.getMaxLanguageLevel(); LanguageLevelProjectExtension extension = LanguageLevelProjectExtension.getInstance(ProjectManager.getInstance().getDefaultProject()); LanguageLevelProjectExtension ext = LanguageLevelProjectExtension.getInstance(project); if (extension.isDefault() || maxLevel.compareTo(ext.getLanguageLevel()) < 0) { ext.setLanguageLevel(maxLevel); ext.setDefault(true); } } }