JetBrains/intellij-community · warning · ConfigurationException

Nothing found to extract

Error message

Nothing found to extract

What it means

ExtractClassDialog.canRun throws ConfigurationException (key dialog.message.nothing.found.to.extract from LangBundle) when the Extract Delegate/Extract Class dialog would run with no members selected: the lists of methods, fields, and inner classes to extract are all empty. The dialog validation prevents launching a refactoring that would create an empty new class.

Source

Thrown at java/java-impl-refactorings/src/com/intellij/refactoring/extractclass/ExtractClassDialog.java:178

                                                                      isExtractAsEnum() ? enumConstants : Collections.emptyList(),
                                                                      createInner.isSelected());
    if (processor.getCreatedClass() == null) {
      Messages.showErrorDialog(myVisibilityPanel, JavaRefactoringBundle.message("extract.delegate.unable.create.warning.message"));
      classNameField.requestFocusInWindow();
      return;
    }
    invokeRefactoring(processor);
  }

  @Override
  protected void canRun() throws ConfigurationException {
    final Project project = sourceClass.getProject();
    final PsiNameHelper nameHelper = PsiNameHelper.getInstance(project);
    final List<PsiMethod> methods = getMethodsToExtract();
    final List<PsiField> fields = getFieldsToExtract();
    final List<PsiClass> innerClasses = getClassesToExtract();
    if (methods.isEmpty() && fields.isEmpty() && innerClasses.isEmpty()) {
      throw new ConfigurationException(LangBundle.message("dialog.message.nothing.found.to.extract"));
    }

    final String className = getClassName();
    if (className.isEmpty() || !nameHelper.isIdentifier(className)) {
      throw new ConfigurationException(JavaBundle.message("invalid.extracted.class.name", className));
    }

    /*final String packageName = getPackageName();
    if (packageName.length() == 0 || !nameHelper.isQualifiedName(packageName)) {
      throw new ConfigurationException("\'" + packageName + "\' is invalid extracted class package name");
    }*/
    for (PsiClass innerClass : innerClasses) {
      if (className.equals(innerClass.getName())) {
        throw new ConfigurationException(
          JavaBundle.message("extracted.class.should.have.unique.name", className));
      }
    }
  }

View on GitHub (pinned to be881553f2)

Solutions

1. Select at least one field, method, or inner class in the members table before running.
2. Use 'Select All'/checkbox shortcuts if you intend to move everything.
3. If the table is empty, verify you invoked Extract Class on a class that actually has extractable members (not an interface with no fields or a class whose members are all inherited).

if (getMethodsToExtract().isEmpty() && getFieldsToExtract().isEmpty() && getClassesToExtract().isEmpty()) {
  // disable OK / show hint: at least one member must be selected
}

try { dialog.canRun(); } catch (ConfigurationException e) { /* nothing selected: check at least one member and retry */ }

When it happens

Trigger: Opening Extract Class (or Extract Delegate on a class) and pressing OK/Run without ticking any checkbox in the members table, or with all members filtered out (e.g. all are inherited/static-initializer-only and not offered).

Common situations: Users hitting Enter expecting the dialog to preselect everything; member lists appearing empty because the class has only constructors or members not eligible for extraction; misunderstanding that at least one member must be chosen.

Related errors

• ''{0}'' is invalid extracted class name
• Extracted class should have unique name. Name ''{0}'' is alr
• Invalid package name: {0}
• ''{0}'' is invalid field name for delegation
• ''{0}'' is invalid parameter name

AI-assisted analysis of JetBrains/intellij-community@be881553f2 (2026-08-14). Data as JSON: /api/errors/35bdf66c57b9aa00. Report an issue: GitHub.