public static void fillCompletionVariants(
      CompletionParameters parameters, CompletionResultSet result) {
    if (parameters.getCompletionType() != CompletionType.BASIC
        && parameters.getCompletionType() != CompletionType.SMART) {
      return;
    }

    PsiElement position = parameters.getPosition();
    if (psiElement(PsiIdentifier.class)
        .withParents(PsiJavaCodeReferenceElement.class, PsiTypeElement.class, PsiClass.class)
        .andNot(JavaCompletionData.AFTER_DOT)
        .andNot(psiElement().afterLeaf(psiElement().inside(PsiModifierList.class)))
        .accepts(position)) {
      suggestGeneratedMethods(result, position);
    } else if (psiElement(PsiIdentifier.class)
        .withParents(
            PsiJavaCodeReferenceElement.class,
            PsiAnnotation.class,
            PsiModifierList.class,
            PsiClass.class)
        .accepts(position)) {
      PsiAnnotation annotation =
          ObjectUtils.assertNotNull(PsiTreeUtil.getParentOfType(position, PsiAnnotation.class));
      int annoStart = annotation.getTextRange().getStartOffset();
      suggestGeneratedMethods(
          result.withPrefixMatcher(
              annotation.getText().substring(0, parameters.getOffset() - annoStart)),
          position);
    }
  }
 public static String findAlphanumericPrefix(CompletionParameters parameters) {
   return findIdentifierPrefix(
       parameters.getPosition().getContainingFile(),
       parameters.getOffset(),
       character().letterOrDigit(),
       character().letterOrDigit());
 }
  @Override
  public void fillCompletionVariants(
      final CompletionParameters parameters, final CompletionResultSet _result) {
    if (parameters.getCompletionType() != CompletionType.BASIC) {
      return;
    }

    final PsiElement position = parameters.getPosition();
    if (!isInJavaContext(position)) {
      return;
    }

    if (AFTER_NUMBER_LITERAL.accepts(position)
        || UNEXPECTED_REFERENCE_AFTER_DOT.accepts(position)) {
      _result.stopHere();
      return;
    }

    final CompletionResultSet result = JavaCompletionSorting.addJavaSorting(parameters, _result);

    if (ANNOTATION_ATTRIBUTE_NAME.accepts(position)
        && !JavaCompletionData.isAfterPrimitiveOrArrayType(position)) {
      JavaCompletionData.addExpectedTypeMembers(parameters, result);
      completeAnnotationAttributeName(result, position, parameters);
      result.stopHere();
      return;
    }

    final InheritorsHolder inheritors = new InheritorsHolder(position, result);
    if (JavaSmartCompletionContributor.IN_TYPE_ARGS.accepts(position)) {
      new TypeArgumentCompletionProvider(false, inheritors)
          .addCompletions(parameters, new ProcessingContext(), result);
    }

    PrefixMatcher matcher = result.getPrefixMatcher();
    if (JavaSmartCompletionContributor.AFTER_NEW.accepts(position)) {
      new JavaInheritorsGetter(ConstructorInsertHandler.BASIC_INSTANCE)
          .generateVariants(parameters, matcher, inheritors);
    }

    if (IMPORT_REFERENCE.accepts(position)) {
      result.addElement(LookupElementBuilder.create("*"));
    }

    addKeywords(parameters, result);

    Set<String> usedWords = addReferenceVariants(parameters, result, inheritors);

    if (psiElement().inside(PsiLiteralExpression.class).accepts(position)) {
      PsiReference reference = position.getContainingFile().findReferenceAt(parameters.getOffset());
      if (reference == null || reference.isSoft()) {
        WordCompletionContributor.addWordCompletionVariants(result, parameters, usedWords);
      }
    }

    JavaGenerateMemberCompletionContributor.fillCompletionVariants(parameters, result);

    addAllClasses(parameters, result, inheritors);

    final PsiElement parent = position.getParent();
    if (parent instanceof PsiReferenceExpression
        && !((PsiReferenceExpression) parent).isQualified()
        && parameters.isExtendedCompletion()
        && StringUtil.isNotEmpty(matcher.getPrefix())) {
      new JavaStaticMemberProcessor(parameters).processStaticMethodsGlobally(matcher, result);
    }
    result.stopHere();
  }
 @Nullable
 public static String findReferencePrefix(CompletionParameters parameters) {
   return CompletionData.getReferencePrefix(parameters.getPosition(), parameters.getOffset());
 }
 public static String findJavaIdentifierPrefix(CompletionParameters parameters) {
   return findJavaIdentifierPrefix(parameters.getPosition(), parameters.getOffset());
 }