private static String generateParameterText(GrTableParameterInfo info) {
    StringBuilder builder = new StringBuilder();
    final PsiTypeCodeFragment typeFragment = info.getTypeFragment();
    String typeText = typeFragment != null ? typeFragment.getText().trim() : GrModifier.DEF;
    if (typeText.length() == 0) typeText = GrModifier.DEF;
    builder.append(typeText).append(' ');
    final GroovyCodeFragment nameFragment = info.getNameFragment();
    builder.append(nameFragment != null ? nameFragment.getText().trim() : "");
    final GroovyCodeFragment defaultInitializer = info.getDefaultInitializerFragment();

    final String defaultInitializerText =
        defaultInitializer != null ? defaultInitializer.getText().trim() : "";
    if (defaultInitializerText.length() > 0) {
      builder.append(" = ").append(defaultInitializerText);
    }
    return builder.toString();
  }
  private boolean validateInputData() {
    if (!isGroovyMethodName(getNewName())) {
      showErrorHint(message("name.is.wrong", getNewName()));
      return false;
    }

    if (!checkType(myReturnTypeCodeFragment, true)) {
      showErrorHint(message("return.type.is.wrong"));
      return false;
    }

    List<GrTableParameterInfo> parameterInfos = myParameterModel.getParameterInfos();
    for (int i = 0; i < parameterInfos.size(); i++) {
      GrTableParameterInfo info = parameterInfos.get(i);
      if (!StringUtil.isJavaIdentifier(info.getName())) {
        showErrorHint(message("name.is.wrong", info.getName()));
        return false;
      }
      if (!checkType(info.getTypeFragment(), i == parameterInfos.size() - 1)) {
        showErrorHint(message("type.for.parameter.is.incorrect", info.getName()));
        return false;
      }
      String defaultValue = info.getDefaultValue();
      final String initializer = info.getDefaultInitializerFragment().getText();
      if (info.getOldIndex() < 0
          && defaultValue.trim().length() == 0
          && initializer.trim().length() == 0) {
        showErrorHint(message("specify.default.value", info.getName()));
        return false;
      }
    }

    ThrownExceptionInfo[] exceptionInfos = myExceptionTableModel.getThrownExceptions();
    PsiTypeCodeFragment[] typeCodeFragments = myExceptionTableModel.getTypeCodeFragments();
    for (int i = 0; i < exceptionInfos.length; i++) {
      ThrownExceptionInfo exceptionInfo = exceptionInfos[i];
      PsiTypeCodeFragment typeCodeFragment = typeCodeFragments[i];
      try {
        PsiType type = typeCodeFragment.getType();
        if (!(type instanceof PsiClassType)) {
          showErrorHint(
              GroovyRefactoringBundle.message(
                  "changeSignature.wrong.type.for.exception", typeCodeFragment.getText()));
          return false;
        }

        PsiClassType throwable =
            JavaPsiFacade.getInstance(myMethod.getProject())
                .getElementFactory()
                .createTypeByFQClassName("java.lang.Throwable", myMethod.getResolveScope());
        if (!throwable.isAssignableFrom(type)) {
          showErrorHint(
              GroovyRefactoringBundle.message(
                  "changeSignature.not.throwable.type", typeCodeFragment.getText()));
          return false;
        }
        exceptionInfo.setType((PsiClassType) type);
      } catch (PsiTypeCodeFragment.TypeSyntaxException e) {
        showErrorHint(
            GroovyRefactoringBundle.message(
                "changeSignature.wrong.type.for.exception", typeCodeFragment.getText()));
        return false;
      } catch (PsiTypeCodeFragment.NoTypeException e) {
        showErrorHint(GroovyRefactoringBundle.message("changeSignature.no.type.for.exception"));
        return false;
      }
    }

    return true;
  }