@Nullable
private PsiType extractContentTypeFromType(
PsiType collectionType) {
if (!(collectionType instanceof PsiClassType)) {
return null;
}
final PsiClassType classType = (PsiClassType)collectionType;
final PsiType[] parameterTypes = classType.getParameters();
if (parameterTypes.length == 0) {
return null;
}
final PsiType parameterType = parameterTypes[0];
if (parameterType == null) {
return null;
}
if (parameterType instanceof PsiWildcardType) {
final PsiWildcardType wildcardType =
(PsiWildcardType)parameterType;
return wildcardType.getExtendsBound();
}
else if (parameterType instanceof PsiCapturedWildcardType) {
final PsiCapturedWildcardType capturedWildcardType =
(PsiCapturedWildcardType)parameterType;
final PsiWildcardType wildcardType =
capturedWildcardType.getWildcard();
return wildcardType.getExtendsBound();
}
return parameterType;
}
private static boolean isIndexedListLoopStatement(PsiForStatement forStatement, boolean ignoreUntypedCollections) {
final PsiStatement initialization = forStatement.getInitialization();
if (!(initialization instanceof PsiDeclarationStatement)) {
return false;
}
final PsiDeclarationStatement declaration = (PsiDeclarationStatement)initialization;
final PsiElement[] declaredElements = declaration.getDeclaredElements();
final PsiElement secondDeclaredElement;
if (declaredElements.length == 1) {
secondDeclaredElement = null;
}
else if (declaredElements.length == 2) {
secondDeclaredElement = declaredElements[1];
}
else {
return false;
}
final PsiElement declaredElement = declaredElements[0];
if (!(declaredElement instanceof PsiVariable)) {
return false;
}
final PsiVariable indexVariable = (PsiVariable)declaredElement;
final PsiExpression initialValue = indexVariable.getInitializer();
if (initialValue == null) {
return false;
}
final Object constant = ExpressionUtils.computeConstantExpression(initialValue);
if (!(constant instanceof Number)) {
return false;
}
final Number number = (Number)constant;
if (number.intValue() != 0) {
return false;
}
final PsiExpression condition = forStatement.getCondition();
final Holder collectionHolder = getCollectionFromSizeComparison(condition, indexVariable, secondDeclaredElement);
if (collectionHolder == null) {
return false;
}
final PsiStatement update = forStatement.getUpdate();
if (!VariableAccessUtils.variableIsIncremented(indexVariable, update)) {
return false;
}
final PsiStatement body = forStatement.getBody();
if (!isIndexVariableOnlyUsedAsListIndex(collectionHolder, indexVariable, body)) {
return false;
}
if (collectionHolder != Holder.DUMMY) {
final PsiVariable collection = collectionHolder.getVariable();
final PsiClassType collectionType = (PsiClassType)collection.getType();
final PsiType[] parameters = collectionType.getParameters();
if (ignoreUntypedCollections && parameters.length == 0) {
return false;
}
return !VariableAccessUtils.variableIsAssigned(collection, body);
}
return true;
}
@Nullable
private PsiType extractListTypeFromContainingClass(
PsiElement element) {
PsiClass listClass = PsiTreeUtil.getParentOfType(element,
PsiClass.class);
if (listClass == null) {
return null;
}
final PsiMethod[] getMethods =
listClass.findMethodsByName("get", true);
if (getMethods.length == 0) {
return null;
}
final PsiType type = getMethods[0].getReturnType();
if (!(type instanceof PsiClassType)) {
return null;
}
final PsiClassType classType = (PsiClassType)type;
final PsiClass parameterClass = classType.resolve();
if (parameterClass == null) {
return null;
}
PsiClass subClass = null;
while (listClass != null && !listClass.hasTypeParameters()) {
subClass = listClass;
listClass = listClass.getSuperClass();
}
if (listClass == null || subClass == null) {
return TypeUtils.getObjectType(element);
}
final PsiTypeParameter[] typeParameters =
listClass.getTypeParameters();
if (!parameterClass.equals(typeParameters[0])) {
return TypeUtils.getObjectType(element);
}
final PsiReferenceList extendsList = subClass.getExtendsList();
if (extendsList == null) {
return null;
}
final PsiJavaCodeReferenceElement[] referenceElements =
extendsList.getReferenceElements();
if (referenceElements.length == 0) {
return null;
}
final PsiType[] types =
referenceElements[0].getTypeParameters();
if (types.length == 0) {
return TypeUtils.getObjectType(element);
}
return types[0];
}
private void checkExpression(@NotNull PsiExpression expression) {
if (expression.getParent() instanceof PsiParenthesizedExpression) {
return;
}
final PsiType expressionType = expression.getType();
if (expressionType == null
|| expressionType.equals(PsiType.VOID)
|| !TypeConversionUtil.isPrimitiveAndNotNull(expressionType)) {
return;
}
final PsiPrimitiveType primitiveType = (PsiPrimitiveType) expressionType;
final PsiClassType boxedType = primitiveType.getBoxedType(expression);
if (boxedType == null) {
return;
}
final PsiType expectedType = ExpectedTypeUtils.findExpectedType(expression, false);
if (expectedType == null || ClassUtils.isPrimitive(expectedType)) {
return;
}
if (!expectedType.isAssignableFrom(boxedType)) {
// JLS 5.2 Assignment Conversion
// check if a narrowing primitive conversion is applicable
if (!(expectedType instanceof PsiClassType) || !PsiUtil.isConstantExpression(expression)) {
return;
}
final PsiClassType classType = (PsiClassType) expectedType;
final String className = classType.getCanonicalText();
if (!convertableBoxedClassNames.contains(className)) {
return;
}
if (!PsiType.BYTE.equals(expressionType)
&& !PsiType.CHAR.equals(expressionType)
&& !PsiType.SHORT.equals(expressionType)
&& !PsiType.INT.equals(expressionType)) {
return;
}
}
if (ignoreAddedToCollection && isAddedToCollection(expression)) {
return;
}
registerError(expression);
}