Code review comment: could set isNull always true in create ArrayType

Code under review:
public Type clickhouseTypeToDoris(JdbcFieldSchema fieldSchema) {
        String ckType = fieldSchema.getDataTypeName();
        boolean isNull = false;
        if (ckType.startsWith("LowCardinality")) {
            ckType = ckType.substring(15, ckType.length() - 1);
            if (ckType.startsWith("Nullable")) {
                isNull = true;
                ckType = ckType.substring(9, ckType.length() - 1);
            }
        } else if (ckType.startsWith("Nullable")) {
            isNull = true;
            ckType = ckType.substring(9, ckType.length() - 1);
        }
        if (ckType.startsWith("Decimal")) {
            String[] accuracy = ckType.substring(8, ckType.length() - 1).split(", ");
            int precision = Integer.parseInt(accuracy[0]);
            int scale = Integer.parseInt(accuracy[1]);
            return createDecimalOrStringType(precision, scale);
        } else if ("String".contains(ckType) || ckType.startsWith("Enum")
                || ckType.startsWith("IPv") || "UUID".contains(ckType)
                || ckType.startsWith("FixedString")) {
            return ScalarType.createStringType();
        } else if (ckType.startsWith("DateTime")) {
            return ScalarType.createDatetimeV2Type(0);
        } else if (ckType.startsWith("Array")) {
            String cktype = ckType.substring(6, ckType.length() - 1);
            fieldSchema.setDataTypeName(cktype);
            Type type = clickhouseTypeToDoris(fieldSchema);
            return ArrayType.create(type, isNull);
        }
        switch (ckType) {
            case "Bool":
                return Type.BOOLEAN;
            case "Int8":
                return Type.TINYINT;
            case "Int16":
            case "UInt8":
                return Type.SMALLINT;
            case "Int32":
            case "UInt16":
                return Type.INT;
            case "Int64":
            case "UInt32":
                return Type.BIGINT;
            case "Int128":
            case "UInt64":
                return Type.LARGEINT;
            case "Int256":
            case "UInt128":
            case "UInt256":
                return ScalarType.createStringType();
            case "Float32":
                return Type.FLOAT;
            case "Float64":
                return Type.DOUBLE;
            case "Date":
            case "Date32":
                return ScalarType.createDateV2Type();
            default:
                return Type.UNSUPPORTED;
        }
        
    }

Line commented on: return ArrayType.create(type, isNull);

Revised code:
public Type clickhouseTypeToDoris(JdbcFieldSchema fieldSchema) {
        String ckType = fieldSchema.getDataTypeName();
        if (ckType.startsWith("LowCardinality")) {
            ckType = ckType.substring(15, ckType.length() - 1);
            if (ckType.startsWith("Nullable")) {
                ckType = ckType.substring(9, ckType.length() - 1);
            }
        } else if (ckType.startsWith("Nullable")) {
            ckType = ckType.substring(9, ckType.length() - 1);
        }
        if (ckType.startsWith("Decimal")) {
            String[] accuracy = ckType.substring(8, ckType.length() - 1).split(", ");
            int precision = Integer.parseInt(accuracy[0]);
            int scale = Integer.parseInt(accuracy[1]);
            return createDecimalOrStringType(precision, scale);
        } else if ("String".contains(ckType) || ckType.startsWith("Enum")
                || ckType.startsWith("IPv") || "UUID".contains(ckType)
                || ckType.startsWith("FixedString")) {
            return ScalarType.createStringType();
        } else if (ckType.startsWith("DateTime")) {
            return ScalarType.createDatetimeV2Type(0);
        } else if (ckType.startsWith("Array")) {
            String cktype = ckType.substring(6, ckType.length() - 1);
            fieldSchema.setDataTypeName(cktype);
            Type type = clickhouseTypeToDoris(fieldSchema);
            return ArrayType.create(type, true);
        }
        switch (ckType) {
            case "Bool":
                return Type.BOOLEAN;
            case "Int8":
                return Type.TINYINT;
            case "Int16":
            case "UInt8":
                return Type.SMALLINT;
            case "Int32":
            case "UInt16":
                return Type.INT;
            case "Int64":
            case "UInt32":
                return Type.BIGINT;
            case "Int128":
            case "UInt64":
                return Type.LARGEINT;
            case "Int256":
            case "UInt128":
            case "UInt256":
                return ScalarType.createStringType();
            case "Float32":
                return Type.FLOAT;
            case "Float64":
                return Type.DOUBLE;
            case "Date":
            case "Date32":
                return ScalarType.createDateV2Type();
            default:
                return Type.UNSUPPORTED;
        }
        
    }