GoGlocalis in the E-Commerce Enablers Industry

GoGlocal

This paper is available on arxiv under CC 4.0 license. Authors: (1) Pietro Ghezzi, Brighton & Sussex Medical School, Falmer, Brighton, UK; (2) Peter G Bannister, Brighton & Sussex Medical School, Falmer, Brighton, UK; (3) Gonzalo Casino, Communication Department, Pompeu Fabra University, Barcelona, Spain and Iberoamerican Cochrane Center, Barcelona, Spain; (4) Alessia Catalani, Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, PU, Italy; (5) Michel Goldman, Institute for Interdisciplinary Innovation in healthcare (I3h), Université libre de Bruxelles; (6) Jessica Morley, Oxford Internet Institute, University of Oxford, Oxford, UK; (7) Marie Neunez, Institute for Interdisciplinary Innovation in healthcare (I3h), Université libre de Bruxelles; (8) Andreu Prados, Communication Department, Pompeu Fabra University, Barcelona, Spain, Iberoamerican Cochrane Center, Barcelona, Spain, Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, PU, Italy, Institute for Interdisciplinary Innovation in healthcare (I3h), Université libre de Bruxelles, Oxford Internet Institute, University of Oxford, Oxford, UK, and Blanquerna School of Health Sciences, Universitat Ramon Llull, Barcelona, Spain; (9) Mariarosaria Taddeo, Oxford Internet Institute, University of Oxford, Oxford, UK, Blanquerna School of Health Sciences, Universitat Ramon Llull, Barcelona, Spain, and The Alan Turing Institute, London, UK; (10) Tania Vanzolini, Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino, PU, Italy; (11) Luciano Floridi, Oxford Internet Institute, University of Oxford, Oxford, UK, Blanquerna School of Health Sciences, Universitat Ramon Llull, Barcelona, Spain, and The Alan Turing Institute, London, UK. Table of Links Abstract and Introduction Methods Web search and content analysis Results Discussion Conclusion and References Table 1. Example of classification of webpages Table 2. Percentage of vaccine-negative webpages in different SERPs Web search and content analysis Searches in English were done from Falmer, Sussex, United Kingdom; in Italian from Urbino, Italy; in French from Bruxelles, Belgium; in Spanish from Barcelona, Spain. Each search was done using a logged-out Chrome browser cleared of cookies and previous search history so that the only identification was the IP address and its geolocalization. Additionally, when available, the local version of each search engine was used (e.g. Google.co.uk and Google.it). For searching Google.com, automatic redirection to google.co.uk was avoided by using the URL Google.com/ncr (no-country-redirect). The first 30 URL results from each search engine result page (SERP), excluding those marked as advertisements, and were transferred to a spreadsheet. When a duplicate URL was encountered, it was excluded. Websites were then visited and the content of each page was coded as vaccine-positive, negative or neutral, depending on the stance taken on the connection between vaccines and autism. Webpages recommending vaccination and/or negating the link with autism were coded as “vaccine-positive”. Those promoting vaccine hesitancy, cautioning about the risk of autism or openly anti-vaccine, were coded as “vaccine-negative”. Additionally, webpages that claimed further studies needed to be conducted to clarify the link between vaccines and autism were also coded as “vaccine-negative”, as previous research by {Browne, 2015 #421} has shown that users perceive this as confirmation of the fact that vaccine safety has not been proven. Webpages simply reporting the history of the anti-vaccine movement or a related legal debate were coded as “vaccine-neutral”. Examples of positive, negative and neutral webpages are provided in Table 1. Coding was completed by two raters for each language and inter-rater agreement was calculated with GraphPad, which uses equations 18.16 to 18.20 from Fleiss 19. On a sample of 59 webpages in English, agreement was 85%, with a Kappa of 0.669 (standard error, 0.077) and a 95% confidence interval from 0.518 to 0.820, a strength of agreement is considered to be 'good' 19. In Italian, agreement was 90%, with a Kappa of 0.818 (standard error, 0.067) and a 95% confidence interval from 0.687 to 0.950, a strength of agreement is considered to be 'very good'. In Spanish, agreement was 83%, with a Kappa of 0.609 (standard error, 0.098) and a 95% confidence interval from 0.418 to 0.801, a strength of agreement is considered to be 'very good'. In French, agreement was 89% with a Kappa of 0.746 (standard error, 0.091) and a 95% confidence interval from 0.568 to 0.924. When frequencies of vaccine-negative webpages was compared across different search engines, we used a two-tailed Fisher’s test corrected for multiple comparison using the method of Benjamini, Krieger and Yekutieli and a false discovery rate (FDR) of 5%.

Online Information of Vaccines: Web Search and Content Analysis

Our users wanted to store app preferences so that every time they use , they can start with the same settings applied. engyne.ai In our case, it was these 3 settings: Author, Publish Status, and Sorting Order. Ideally, once you select these, they should be selected permanently, even if you navigate away or log out. To do this, we decided to build a custom hook that would load and store user preferences from local storage. Since the user can have multiple projects, the preferences should be saved per project. Setting up the Local Storage The name of the key would be: . The subdomain is the project name. For example - engyne-user-prefs-{{subdomain}} engyne-user-prefs-hackernoon. This way, each key would have its own . This type represents the settings that will be stored. UserPrefsType export type UserPrefsType = {
  sortType: string,
  publishingStatusFilter: string,
  authorFilter: string,
} Creating the React Hook Now that we know the key/value to store in the local storage, here’s how we create the React hook called to both save and get value from the local storage. useUserPrefs Note that you can only store strings in the local storage, so all JSON has to be stringified when saving and parsed when retrieving. We also specify a default value in case the project to get the user prefs is not specified. //hooks/useUserPrefs.ts

import { useEffect, useState } from "react";
import { PostPublishStatus, PostSortType } from "/types";

export type UserPrefsType = {
  sortType: string,
  publishingStatusFilter: string,
  authorFilter: string,
}

const defaultUserPrefs: UserPrefsType = {
  sortType: PostSortType.NEWEST,
  publishingStatusFilter: PostPublishStatus.ALL,
  authorFilter: "",
}

const getLocalStorage = (key: string): UserPrefsType => {
  let currentValue;
  try {
    currentValue = JSON.parse(
      localStorage.getItem(key) || JSON.stringify(defaultUserPrefs)
    );
  } catch (error) {
    return defaultUserPrefs;
  }

  return currentValue;
}

const useUserPrefs = (subdomain: string) => {
  const key = `engyne-user-prefs-${subdomain}`

  const [value, setValue] = useState<UserPrefsType>(() => {
    if (!subdomain) return defaultUserPrefs;
    return getLocalStorage(key)
  });

  useEffect(() => {
    if (!subdomain) return;
    const currentValue = getLocalStorage(key);
    setValue(currentValue);
  }, [subdomain])

  useEffect(() => {
    if (!subdomain || !value) return;
    localStorage.setItem(key, JSON.stringify(value))
  }, [value])

  const updateUserPrefs = (userPref: Partial<UserPrefsType>) => {
    if (!subdomain) return;
    const currentValue = getLocalStorage(key);
    const updatedUserPrefs = { ...currentValue, ...userPref }
    setValue(updatedUserPrefs);
  }

  return { userPrefs: value, updateUserPrefs };
};

export default useUserPrefs; Use the Hook in the Application Now, we can import this hook into the application and get the saved author value from the local storage. First, we set up the hook to get the specified project’s user prefs, then we set the author value using the . userPrefs.authorFilter The is used whenever the user selects a different author name. updateUserPrefs import {
  Select,
} from "@chakra-ui/react";

const subdomain = "hackernoon"

const { userPrefs, updateUserPrefs } = useUserPrefs(subdomain)
const authorsData = ["Author 1", "Author 2"]

// in component

<Select size="md" color="gray.600" width="unset" variant="unstyled" placeholder="Select author" onChange={(evt) => {
                  updateUserPrefs({ authorFilter: evt.target.value })
                }} value={userPrefs.authorFilter}>
                  {authorsData.map((author: any, i: number) => (
                    <option key={`author_${i}`} value={author.id}>
                      {author.name}
                    </option>
                  ))}
                </Select> This is what the saved user prefs look like in local storage.

How We Store User Prefs in Local Storage Using Hooks in Next.js

Even with the multitude of libraries available today, it can sometimes be challenging to find one that offers the specific functionality needed for a particular task. Instead of spending time searching for the perfect library, I recommend crafting your own implementation; even if it's tailored specifically for one project. Once, I found myself in need of a library that could easily convert data classes into an Excel document for report generation. When I couldn't locate a suitable library, I decided to develop functionality tailored to my specific needs. My ambition was to design a library akin to Jackson, which would use annotations to transform a list of data classes into an Excel document as dictated by the annotations. I want to share the library I created, hoping it may benefit others or inspire them to create their own mapper for their unique tasks. Let's explore how to develop in Java such a data mapper to achieve this: from this: void demoReport() {
    var excelMapper = new ExcelMapperImpl();

    var fileName = "demo-out-" + LocalTime.now() + ".xlsx";
    List<Demo> demos = generateDemos();

    try (Workbook workbook = excelMapper.createWorkbookFromObject(demos);
         var fileOutputStream = new FileOutputStream(fileName)) {
        workbook.write(fileOutputStream);
    }
} Defining Annotations Let's identify the main elements essential for Excel mapping. At its core, we require an Excel column. This foundational component of the report should distinctly showcase the column name and the corresponding value in each row. Moreover, we must incorporate support for formula cells, allowing us to utilize values and present the results dynamically. At the column's end, a concluding formula is essential, whether it represents an average, sum, or any other pertinent metric for the end-user. Beyond mere data cells, we should also integrate features to easily manage cell styling. After identifying the essential elements, the next step is to craft the necessary annotations. The initial annotation will embed metadata about cell styling. This annotation will encompass fundamental attributes along with their default values: @Retention(RetentionPolicy.RUNTIME)
public @interface ColumnExcelStyle {
    ExcelColumnDataFormat cellTypePattern() default ExcelColumnDataFormat.NONE;
    IndexedColors cellColor() default IndexedColors.AUTOMATIC;

    boolean isWrapText() default false;

    boolean isCentreAlignment() default false;

    boolean isFramed() default true;

    ExcelColumnFont fontName() default ExcelColumnFont.DEFAULT;

    short fontSize() default -1;

    boolean isFontBold() default false;

    ExcelColumnCellTextColor fontColor() default ExcelColumnCellTextColor.AUTOMATIC;
} The primary style elements crucial for report creation are conveyed as attributes. Following this, the initiation of an Excel column annotation can be undertaken: @Target({ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
public @interface ColumnExcel {
    String[] applyNames() default {};

    int position();

    ColumnExcelStyle headerStyle() default @ColumnExcelStyle(
            fontColor = ExcelColumnCellTextColor.BLACK,
            isCentreAlignment = true,
            isFontBold = true,
            fontSize = 14,
            isWrapText = true);

    ColumnExcelStyle cellStyle() default @ColumnExcelStyle;
} This annotation encompasses potential column names (for mapping from Excel) and a mandatory field - ' '. This will determine the column's placement and be instrumental in formula calculations. Additionally, it will detail the style of both the header and the cell. position Excellent. Now, let's formulate an annotation specific to Excel formulas. Anticipating a dynamic formula contingent on the row's position, this annotation will be exclusive to methods: @Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface ColumnExcelFormula {
    String name() default "";

    int position();

    ColumnExcelStyle headerStyle() default @ColumnExcelStyle(
            fontColor = ExcelColumnCellTextColor.BLACK,
            isCentreAlignment = true,
            isFontBold = true,
            fontSize = 14,
            isWrapText = true);

    ColumnExcelStyle cellStyle() default @ColumnExcelStyle;
} Lastly, let’s introduce an annotation for the culminating formula, which typically occupies the final row in Excel, summarizing or illustrating the cumulative result for a column. Given that the formula's annotation also mandates its applicability solely to methods: @Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface ColumnExcelTotalFormula {
    boolean useValue() default false;

    int position();

    ColumnExcelStyle cellStyle() default @ColumnExcelStyle;
} Building an Excel Reporting Service With Apache POI After the creation of all necessary annotations, crafting a service class becomes the next step. The core library utilized will be , effective for working with .xls and .xlsx files. This class will use annotations’ attributes to generate an Excel report. Apache POI The primary method accepts a list of objects as input and returns a prepared workbook. For added flexibility, an overloaded method will be introduced to enable the specification of both the file name and the sheet name for report generation: <T> Workbook createWorkbookFromObject(List<T> reportObjects) {
    return createWorkbookFromObject(reportObjects, 0, "Report");
}

<T> Workbook createWorkbookFromObject(List<T> reportObjects, 
                                      int startRowNumber, 
                                      String sheetName) {
...
} To extract information about the class using reflection, any element from the array is selected. After accessing the class details, the first row can be established. Utilizing data from the annotation allows for the creation of cells with their respective names. If a name is absent, the class field's name can serve as an alternative: private <T> void createHeaderFromDeclaredExcelColumns(Row row, Class<T> clazz, PropertyDescriptor propertyDescriptor) {
    try {
        Field field = clazz.getDeclaredField(propertyDescriptor.getName());

        ColumnExcel columnExcel = field.getDeclaredAnnotation(ColumnExcel.class);
        if (nonNull(columnExcel)) {
            String headerName = columnExcel.applyNames().length > 0 ? columnExcel.applyNames()[0] : field.getName();
            createHeader(row, columnExcel.position(), headerName, columnExcel.headerStyle());
        }
    } catch (NoSuchFieldException e) {
        log.debug(e.getLocalizedMessage());
    }
} When fashioning the header, remember to assign a style to every cell. Style parameters can be derived from the annotation: @ColumnExcelStyle private void createHeader(Row row, int position, String name, ColumnExcelStyle columnExcelStyle) {
    Cell cell = row.createCell(position);
    cell.setCellValue(name);

    setCellFormatting(cell, columnExcelStyle);
    row.getSheet().autoSizeColumn(cell.getColumnIndex());
} The process then turns to generating rows in the report based on data from the provided array. By iterating over the data, successive rows are formed: for (T report : reportObjects) {
    Row bodyRow = sheet.createRow(proceedRowNumber);
    createCellsFromDeclaredExcelColumns(bodyRow, report);
    proceedRowNumber++;
} Property descriptors are procured to utilize getters instead of granting direct access to fields: private <T> void createCellsFromDeclaredExcelColumns(Row row, T tObject) {
    try {
        PropertyDescriptor[] propertyDescriptors = Introspector.getBeanInfo(tObject.getClass()).getPropertyDescriptors();

        for (var propertyDescriptor : propertyDescriptors) {
            createCellFromDeclaredExcelColumns(row, tObject, propertyDescriptor);
        }
    } catch (IntrospectionException ex) {
        log.debug(ex.getLocalizedMessage());
    }
} With the property descriptor, a cell is formed: private <T> void createCellFromDeclaredExcelColumns(Row row, T tObject, PropertyDescriptor propertyDescriptor) {
    try {
        Field field = tObject.getClass().getDeclaredField(propertyDescriptor.getName());
        Method readMethod = propertyDescriptor.getReadMethod();

        ColumnExcel columnExcel = field.getDeclaredAnnotation(ColumnExcel.class);
        if (nonNull(columnExcel)) {
            Class<?> returnType = readMethod.getReturnType();
            Cell cell = row.createCell(columnExcel.position());

            Object invokeResult = readMethod.invoke(tObject);
            if (nonNull(invokeResult)) {
                defineAndAssignCellValue(returnType, cell, invokeResult, readMethod);
            }
            setCellFormatting(cell, columnExcel.cellStyle());
        }
    } catch (NoSuchFieldException | InvocationTargetException | IllegalAccessException e) {
        log.debug(e.getLocalizedMessage());
    }
} Next, let’s turn our attention to processing the annotations. Crafting formulas proves slightly more complex than simply extracting a value from a field. A method is expected to generate a formula, which is subsequently assigned to the cell. @ColumnExcelFormula The method should consistently return a string and accept the row number as an argument, ensuring accurate data usage from adjacent cells. Thus, it falls on the handler to verify these conditions are met before forming the cell with the specified formula: private <T> void createCellFromDeclaredExcelFormula(Row row, T tObject, Method readMethod) throws IllegalAccessException, InvocationTargetException {
    ColumnExcelFormula columnExcelFormula = readMethod.getDeclaredAnnotation(ColumnExcelFormula.class);
    if (columnExcelFormula != null) {
        Class<?> returnType = readMethod.getReturnType();
        Cell cell = row.createCell(columnExcelFormula.position());

        if (returnType.isAssignableFrom(String.class)) {
            cell.setCellFormula((String) readMethod.invoke(tObject, row.getRowNum()));
        } else {
            log.debug(" Return type for the method: " + readMethod.getName() + " with @ColumnExcelFormula annotation has to be String " +
                    "and now it's: " + returnType.getName() + " method is ignored for the reason");
        }
        setCellFormatting(cell, columnExcelFormula.cellStyle());
    }
} The final step involves creating a row to display the concluding results. Importantly, this row should be generated only once, irrespective of the number of objects relayed to the handler. An annotation in a static method is anticipated for this purpose. This method receives both the number of the initial row and the current row where the cell will be instantiated as arguments. Provision of the initial row's number is vital, enabling the method to devise a formula that leverages the aggregate result for the entire column: private <T> void createTotalFormula(Class<T> tClazz, Row row, int firstRowNum) {
    Method[] methods = tClazz.getDeclaredMethods();
    for (Method method : methods) {
        ColumnExcelTotalFormula columnExcelTotalFormula = method.getAnnotation(ColumnExcelTotalFormula.class);
        if (columnExcelTotalFormula != null
                && method.getReturnType().isAssignableFrom(String.class)
                && method.getParameters().length == 2
                && Modifier.isStatic(method.getModifiers())
                && !Modifier.isPrivate(method.getModifiers())
        ) {
            String cellFormula = (String) method.invoke(tClazz, firstRowNum, row.getRowNum());
            Cell cell = row.createCell(columnExcelTotalFormula.position());
            cell.setCellFormula(cellFormula);

            if (columnExcelTotalFormula.useValue()) {
                cell = applyFormulasValue(cell);
            }
            setCellFormatting(cell, columnExcelTotalFormula.cellStyle());
        }
    }
} Making a Report The main functionality is now in place, and it's time to see it in action. Let's construct a simple report to demonstrate its operation. For this, let’s create a ' ' class and incorporate all the necessary annotations: Sales @Data
@Accessors(chain = true)
public class Sales {

    @ColumnExcel(
            position = 0, applyNames = {"Date"},
            headerStyle = @ColumnExcelStyle(
                              fontColor = WHITE, 
                              cellColor = DARK_BLUE, 
                              isCentreAlignment = true),
            cellStyle = @ColumnExcelStyle(
                            cellColor = GREY_25_PERCENT, 
                            cellTypePattern = DATE))
    private LocalDate date;

    @ColumnExcel(
            position = 1, applyNames = {"Sold"},
            headerStyle = @ColumnExcelStyle(
                            fontColor = WHITE, 
                            cellColor = DARK_BLUE, 
                            isCentreAlignment = true),
            cellStyle = @ColumnExcelStyle(
                          cellColor = GREY_25_PERCENT))
    private Integer sold;

    @ColumnExcel(
            position = 2, 
            applyNames = {"Price Per Unit (USD)"},
            headerStyle = @ColumnExcelStyle(
                            fontColor = WHITE, 
                            cellColor = DARK_BLUE, 
                            isCentreAlignment = true),
            cellStyle = @ColumnExcelStyle(
                          cellColor = GREY_25_PERCENT, 
                          cellTypePattern = USD))
    private Double pricePerUnit;

    @ColumnExcelFormula(
            position = 3, 
            name = "Total Sales (USD)",
            headerStyle = @ColumnExcelStyle(
                             fontColor = WHITE, 
                             cellColor = DARK_BLUE, 
                             isCentreAlignment = true),
            cellStyle = @ColumnExcelStyle(
                            cellColor = GREY_25_PERCENT, 
                            cellTypePattern = USD))
    public String sales(int rowNum) {
        return new CellAddress(rowNum, 1).formatAsString()
                + "*"
                + new CellAddress(rowNum, 2).formatAsString();
    }

    @ColumnExcelTotalFormula(
            position = 0,
            cellStyle = @ColumnExcelStyle(
                           cellColor = LIGHT_BLUE))
    public static String total(int firstRowNum, int lastRowNum) {
        return "CONCATENATE(\"Total\")";
    }

    @ColumnExcelTotalFormula(
            position = 1,
            cellStyle = @ColumnExcelStyle(
                          cellColor = LIGHT_BLUE))
    public static String unitsSold(int firstRowNum, int lastRowNum) {
        return "SUM(" + new CellAddress(firstRowNum, 1).formatAsString() + ":"
                + new CellAddress(lastRowNum - 1, 1).formatAsString() + ")";
    }


    @ColumnExcelTotalFormula(
            position = 3,
            cellStyle = @ColumnExcelStyle(
                          isCentreAlignment = false, 
                          cellColor = LIGHT_BLUE, 
                          cellTypePattern = USD))
    public static String totalSales(int firstRowNum, int lastRowNum) {
        return "SUM(" + new CellAddress(firstRowNum, 3).formatAsString() + ":"
                + new CellAddress(lastRowNum - 1, 3).formatAsString() + ")";
    }
} The class comprises three fields: , , and . Additionally, it has a sales formula and a concluding line with the totals: and . The fields utilize the annotation, denoting the column's position and name. date sold pricePerUnit unitsSold totalSales @ColumnExcel The annotation defines the style for both the header and individual data cells: @ColumnExcelStyle @ColumnExcel(
        position = 0, 
        applyNames = {"Date"},
        headerStyle = @ColumnExcelStyle(
                          fontColor = WHITE, 
                          cellColor = DARK_BLUE, 
                          isCentreAlignment = true),
        cellStyle = @ColumnExcelStyle(
                          cellColor = GREY_25_PERCENT, 
                          cellTypePattern = DATE)
) As previously discussed, when creating a formula, the method must accept a parameter indicating the row number. This requirement is evident in the method's signature: public String sales(int rowNum) {
        return new CellAddress(rowNum, 1).formatAsString()
                + "*"
                + new CellAddress(rowNum, 2).formatAsString();
    } Given the row number and column indices, crafting any specific formula becomes feasible. Within the class, methods intended for the concluding formulas are static and require two parameters: the starting row's number and the ending row's number: public static String unitsSold(int firstRowNum, int lastRowNum) {
        return "SUM(" + 
                new CellAddress(firstRowNum, 1).formatAsString() + 
                ":" + 
                new CellAddress(lastRowNum - 1, 1).formatAsString() + 
                ")";
    } Now, let's launch the method: void salesReport() {
    var excelMapper = new ExcelMapperImpl();

    var fileName = "sales-out-" + LocalTime.now() + ".xlsx";
    List<Sales> sales = List.of(
                new Sales().setDate(LocalDate.of(2023, 1, 1))
                        .setSold(50)
                        .setPricePerUnit(10d),
                new Sales().setDate(LocalDate.of(2023, 1, 2))
                        .setSold(40)
                        .setPricePerUnit(11d),
                new Sales().setDate(LocalDate.of(2023, 1, 3))
                        .setSold(55)
                        .setPricePerUnit(9d);

    try (Workbook workbook = excelMapper.createWorkbookFromObject(sales);
         var fileOutputStream = new FileOutputStream(fileName)) {
        workbook.write(fileOutputStream);
    }
} And examine the generated report: Conclusion Writing a specialized library for a specific task proved to be straightforward. The library crafted meets the requirements and includes the planned functionality. The approach utilizing annotations facilitates quick and convenient customization of cell styles, modification of formulas, and dynamic report creation from varied data sources. Hence, the next time a suitable library is elusive, considering the development of a personalized one might be beneficial. Naturally, presenting every line of code in this article was not feasible; thus, only the primary methods essential to the mapper's operation were highlighted. The complete code is available on my . GitHub page

From Data Classes to Excel: Building a Java Mapper With Annotations

ডেটা ক্লাস থেকে এক্সেল পর্যন্ত: টীকা সহ একটি জাভা ম্যাপার তৈরি করা

Von Datenklassen bis Excel: Erstellen eines Java-Mappers mit Anmerkungen

De clases de datos a Excel: creación de un asignador de Java con anotaciones

Des classes de données à Excel : créer un mappeur Java avec des annotations

डेटा क्लास से एक्सेल तक: एनोटेशन के साथ जावा मैपर का निर्माण

データ クラスから Excel へ: 注釈を備えた Java マッパーの構築

데이터 클래스에서 Excel까지: 주석을 사용하여 Java 매퍼 구축

Das classes de dados ao Excel: construindo um mapeador Java com anotações

От классов данных к Excel: создание Java Mapper с аннотациями

Veri Sınıflarından Excel'e: Ek Açıklamalarla Java Eşleyici Oluşturma

Từ các lớp dữ liệu đến Excel: Xây dựng trình ánh xạ Java bằng chú thích

从数据类到 Excel：使用注释构建 Java 映射器

In the ever-evolving landscape of cyber threats, ransomware has proven to be one of the most notorious and damaging forms of attack. Among the various ransomware variants, RagnarLocker has garnered significant attention for its sophisticated tactics and impact on critical infrastructure sectors. In this blog post, we delve into the world of RagnarLocker ransomware, exploring its indicators of compromise (IOCs), technical intricacies, and the havoc it wreaks on targeted systems. 💥🔓 Ransomware Strikes Israeli Hospital: Ragnar_Locker Takes Responsibility 🏥 In a chilling turn of events, RagnarLocker’s menace struck closer to home as it targeted Mayanei Hayeshua Medical Center in Bnei Brak, Israel a few days ago. The ransomware attack wreaked havoc on the hospital’s administrative computer systems. The aftermath was devastating — medical treatments were disrupted, and the emergency room was compelled to redirect patients to other hospitals for urgent care. Emerging from the chaos, Ragnar_Locker took responsibility for this audacious attack. However, I’ve made a detailed investigation that yielded no signs of any leaked data or information on the group’s Onion site or Telegram group. This marks an unusual departure from the norm, where cybercriminals often flaunt their exploits on such platforms. This incident serves as a grim reminder of the vulnerabilities lurking in critical infrastructure sectors, with healthcare being no exception. It underscores the pressing need for fortified cybersecurity measures to shield essential services from such malicious onslaughts. As the investigation into this unsettling event progresses, the global cybersecurity community will undoubtedly be closely monitoring further developments. 🌐🔒🦠 The Emergence of RagnarLocker 🌄💻 The first traces of RagnarLocker ransomware came to light in April 2020, catching the attention of cybersecurity experts and organizations worldwide. Notably, the Federal Bureau of Investigation (FBI) issued an initial report detailing known IOCs associated with RagnarLocker. Over time, this ransomware variant has evolved, refining its obfuscation techniques and evading traditional detection methods. 🚀🔍 A Persistent Threat 🎯🌐 As of January 2022, the FBI has identified over 52 entities spanning across 10 critical infrastructure sectors affected by RagnarLocker ransomware. These sectors encompass critical manufacturing, energy, financial services, government, and information technology, underscoring the ransomware’s indiscriminate targeting. 💼🏢🔒 Technical Insights 🔍💡 Ransom Note and Identification: RagnarLocker is recognizable by the “.RGNR_<ID>” extension appended to encrypted files. The actors, self-identifying as “RAGNAR_LOCKER,” accompany this extension with a .txt ransom note, containing instructions for payment and data decryption. 💰🔐📄 Advanced Packing Techniques: The ransomware employs advanced techniques like VMProtect, UPX, and custom packing algorithms, adding layers of complexity to its execution. This obfuscation serves to complicate detection efforts. 🧩🔒🔍 Geographical Targeting: RagnarLocker uses the Windows API GetLocaleInfoW to identify the infected machine’s location. If the victim’s location falls within certain geopolitical areas, the ransomware terminates its processes, potentially hinting at the attackers’ geopolitical motivations. 🗺️🌍🔍 Selective Encryption: Instead of opting for a widespread encryption approach, RagnarLocker selectively encrypts files. It designates folders it won’t encrypt, allowing the system to function “normally” while encrypting files with valuable data. This method minimizes disruptions while maximizing the potential payout. 📁🔒🤖 Before encryption, Ragnar Locker spawns the following child processes: This system command deletes all shadow copies on the victim’s system, preventing data recovery by the victim : wmic.exe shadowcopy delete This system command also deletes shadow copies, preventing data recovery by the victim : vssadmin delete shadows /all /quiet This command launches Notepad.exe to show the ransom note to the victim. : notepad.exe [User path]\RGNR_AABBCCDD.txt After the ransom note is created, the actual file encryption process initiates using the __ __algorithm. It excludes files ending in . Salsa20 db, .sys, .dll, lnk, .msi, .drv and .exe. Neutralizing Defenses 🛡️🚫 Service Termination: RagnarLocker goes a step further in its attack strategy by identifying and terminating services commonly used by managed service providers (MSPs) for remote network administration. This further hampers recovery efforts. 💔🔧 Shadow Copy Deletion: Preventing victim recovery efforts, the ransomware erases Volume Shadow Copies, a mechanism used to restore files to previous states. The malware employs various methods, including >vssadmin delete shadows /all /quiet and >wmic.exe.shadowcopy.delete. 🗑️🔮 Conclusion 📢🔐 RagnarLocker ransomware presents a multifaceted threat that combines advanced technical techniques with an intricate attack strategy. Its evolution since its discovery in 2020, along with its targeting of critical infrastructure sectors, underscores the urgency of bolstering cybersecurity measures to defend against this and similar threats. As organizations and security experts continue to dissect RagnarLocker’s mechanisms, it becomes increasingly evident that the fight against ransomware demands a proactive and collaborative approach, where vigilance and innovation go hand in hand. 🛡️🌐🔒 References: https://www.timesofisrael.com/liveblog_entry/bnei-brak-hospital-bracing-for-release-of-sensitive-patient-information-after-hack/ https://www.ic3.gov/Media/News/2022/220307.pdf https://www.linkedin.com/showcase/dailydarkweb/ https://www.pcrisk.com/removal-guides/17018-ragnar-locker-ransomware Also published . here

Uncovering Ragnar_Locker Ransomware: Exploring IOCs

Last week, we described the concept behind : you forward a request to the same upstream because there's context data associated with the session on that node. However, if necessary, you should replicate the data to other upstreams because this one might go down. In this post, we are going to illustrate it with a demo. sticky sessions Content Overview The overall design The heart of the application Configuring Spring Session with Hazelcast Configuring Spring Security Putting our design to the test Conclusion The overall design Design options are limitless. I'll keep myself to a familiar stack, the JVM. Also, as mentioned in the previous post, one should only implement sticky sessions with session replication. The final design consists of two components: an instance with sticky sessions configured and two JVM nodes running the same application with session replication. Apache APISIX The application uses the following: Dependency Description Spring Boot Eases the usage of Spring libraries Spring MVC Allows offering HTTP endpoints Thymeleaf View technology Spring Session Offers an abstraction over session replication Hazelcast (embedded) Implements session replication Spring Security Binds an identity to a user session The design looks like the following: and are two instances of the same app; I didn't want to overcrowd the diagram with redundant data. app1 app2 The heart of the application The heart of the application is a session-scoped bean that wraps a counter, which can only be incremented: @Component
@SessionScope
public class Counter implements Serializable {              //1

    private int value = 0;

    public int getValue() {
        return value;
    }

    public void incrementValue() {
        value++;
    }
} Necessary for Hazelcast serialization to work We can use this bean in the controller: @Controller
public class IndexController {

    private final Counter counter;

    public IndexController(Counter counter) {               //1
        this.counter = counter;
    }

    @GetMapping("/")
    public String index(Model model) {                      //2
        counter.incrementValue();
        model.addAttribute("counter", counter.getValue());
        return "index";
    }
} Inject the session-scoped bean in the singleton controller thanks to Spring's magic When we send a request to the root, increment the counter value and pass it to the model GET Finally, we display the bean's value on the Thymeleaf page: <!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org" lang="en">
<body>
<div th:text="${counter}">3</div> Configuring Spring Session with Hazelcast Spring Session offers a filter that wraps the original to override the method. This method returns a specific implementation backed by the implementation configured with Spring Session, in our case, HttpServletRequest getSession() Session Hazelcast. We need only a few tweaks to configure Spring Session with Hazelcast. First, annotate the Spring Boot application class with the relevant annotation: @SpringBootApplication
@EnableHazelcastHttpSession
public class SessionApplication {
    ...
} Hazelcast requires a specific configuration as well. We can use XML, YAML, or code. Since it's a demo, I can choose whatever I want, so let's code it. Spring Boot requires either an Hazelcast object or a configuration object. The latter is enough: @Bean
public Config hazelcastConfig() {
  var config = new Config();
  var networkConfig = config.getNetworkConfig();
  networkConfig.setPort(0);                                                      //1
  networkConfig.getJoin().getAutoDetectionConfig().setEnabled(true);              //2
  var attributeConfig = new AttributeConfig()                                     //3
          .setName(HazelcastIndexedSessionRepository.PRINCIPAL_NAME_ATTRIBUTE)
          .setExtractorClassName(PrincipalNameExtractor.class.getName());
  config.getMapConfig(HazelcastIndexedSessionRepository.DEFAULT_SESSION_MAP_NAME) //3
          .addAttributeConfig(attributeConfig)
          .addIndexConfig(new IndexConfig(
            IndexType.HASH,
            HazelcastIndexedSessionRepository.PRINCIPAL_NAME_ATTRIBUTE
  ));
  var serializerConfig = new SerializerConfig();
  serializerConfig.setImplementation(new HazelcastSessionSerializer())            //3
                  .setTypeClass(MapSession.class);
  config.getSerializationConfig().addSerializerConfig(serializerConfig);
  return config;
} Choose a random port to avoid port conflict Allow Hazelcast to search for other instances and automagically form a cluster. It's going to be necessary when deployed as per our design Copy-pasted from the Spring Session documentation Configuring Spring Security Most Spring Session examples somehow use Spring Security, and though it's not strictly necessary, it makes the design easier. I want to explain why first. One can think about sessions as a gigantic hash table. In regular applications, the key is the cookie value, the value, and another hash table of session data. However, the is specific to the node. The app will give a different if one uses another node. Since the key is different, there's no way to access the session data, even if the session data is shared across nodes. To prevent this loss, we need to come up with a different key. Spring Security allows using a principal (or the login name) as the session data key. JSESSIONID JSESSIONID JSESSIONID Here's how I set up a basic Spring Security configuration: @Bean
public SecurityFilterChain securityFilterChain(UserDetailsService service, HttpSecurity http) throws Exception {
  return http.userDetailsService(service)                                    //1
             .authorizeHttpRequests(authorize -> authorize.requestMatchers(
                 PathRequest.toStaticResources().atCommonLocations())        //2
                            .permitAll()                                     //2
                            .anyRequest().authenticated()                    //3
             ).formLogin(form -> form.permitAll()
                                     .defaultSuccessUrl("/")                 //4
             ).build();
} The default in-memory user details service doesn't allow custom user details classes. I had to provide my own. Allow everybody to access static resources at "common" locations All other requests must be authenticated Allow everybody to access the authentication form Redirect to the root if successful, which maps the above controller Putting our design to the test Besides the counter, I want to display two additional pieces of data: the hostname and the logged-in user. For the hostname, I add the following method to the controller: @ModelAttribute("hostname")
private String hostname() throws UnknownHostException {
    return InetAddress.getLocalHost().getHostName();
} Displaying the logged-in user requires an additional dependency: <dependency>
    <groupId>org.thymeleaf.extras</groupId>
    <artifactId>thymeleaf-extras-springsecurity6</artifactId>
</dependency> On the page, it's straightforward: <!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org"
      xmlns:sec="http://www.thymeleaf.org/extras/spring-security">  
<body>
<td sec:authentication="principal.label">Me</td>                     Add the namespace. It's not necessary but may help the IDE to help you sec Require the underlying implementation to have a method UserDetail getLabel() Last but not least, we need to configure Apache APISIX with sticky sessions, as we saw last week: routes:
  - uri: /*
    upstream:
      nodes:
        "webapp1:8080": 1
        "webapp2:8080": 1
      type: chash
      hash_on: cookie
      key: cookie_JSESSIONID
#END Here's the design implemented on Docker Compose: services:
  apisix:
    image: apache/apisix:3.3.0-debian
    volumes:
      - ./apisix/config.yml:/usr/local/apisix/conf/config.yaml:ro
      - ./apisix/apisix.yml:/usr/local/apisix/conf/apisix.yaml:ro    #1
    ports:
      - "9080:9080"                                                  #2
    depends_on:
      - webapp1
      - webapp2
  webapp1:
    build: ./webapp
    hostname: webapp1                                                #3
  webapp2:
    build: ./webapp
    hostname: webapp2                                                #3 Use the previous configuration file Only expose the API Gateway to the outside world Set the hostname to display it on the page We can log in using one of the two hard-coded accounts. I'm using , with password and label . Notice that Apache APISIX sets me on a node and keeps using the same if I refresh. john john John Doe We can try to log in with the other account ( / ) from a private window and check the counter starts from 0. jane jane Now comes the fun part. Let's stop the node which should be hosting the session data, here and refresh the page: webapp2 docker compose stop webapp2 We can see exciting things in the logs. Apache APISIX can no longer find the , so it forwards the request to the other upstream that it knows, . webapp2 webapp1 The request is still authenticated; it goes through Spring Security The framework gets the principal out of the request It queries Spring Session And gets the correct counter value that Hazelcast replicated from the other node The only side-effect is an increased latency because of Apache APISIX timeout. It's 5 seconds by default, but you can configure it to a lower value if needed. When we start again, everything works as expected again. webapp2 Conclusion In this post, I described a possible setup for sticky sessions with Apache APISIX and replication involving the Spring ecosystem and Hazelcast. Many other options are available depending on your stack and framework of choices. The complete source code for this post can be found on . GitHub To go further: Spring Session and Spring Security with Hazelcast Spring Session Hazelcast Originally published at on July 2nd, 2023 A Java Geek

Demo: Sticky Sessions with Apache APISIX for Improved Load Balancing

Building Your Own Programming Language From Scratch: Part IX - Hybrid Inheritance

Building Your Own Programming Language From Scratch: Part VII - Classes

Construyendo su propio lenguaje de programación desde cero: Parte VII - Clases

Construire votre propre langage de programmation à partir de zéro : partie VII - Classes

स्क्रैच से अपनी खुद की प्रोग्रामिंग लैंग्वेज बनाना: भाग VII - कक्षाएं

ゼロから独自のプログラミング言語を構築する: パート VII - クラス

Construindo sua própria linguagem de programação do zero: Parte VII - Aulas

Xây dựng ngôn ngữ lập trình của riêng bạn từ đầu: Phần VII - Các lớp học

从头开始构建您自己的编程语言：第七部分 - 类

In this article, I’ll make an overview of what I’ve learned from Alexis Roussel, the COO of Nym, who read the lecture “Nym technologies and how they protect your privacy” for Shipyard Academy students on November, 10. Privacy and who needs it Privacy is a broad term, but, briefly speaking, it is the ability to share what you want with whom you want and how you want to do it. So, privacy is about the selective disclosure of your personal information. You may think of privacy as a synonym for seclusion, but there is one interesting thing about it. As Alexis said, in Nym they have a motto “Privacy loves company”, because a lot of people are needed to hide the communication between them. The larger we are, the better anonymity and privacy we’ll have. Imagine you are alone in the park, speaking to your friend. If someone wants to overhear what you are discussing, they can easily do it, because you are visible and hearable very well. But if there are 10 people around, seeing and hearing becomes more difficult. And what if you are surrounded by 1000 people, all wearing the same clothes and facial masks, and all of them speaking loudly? It’ll become almost impossible to overhear you chatting with your friend. So, privacy is about making sure that we are hidden in the sea of anonymity. For some people, this is crucial to protect themselves against the threats they encounter in their lives. One example is women in the US, looking for health advice about abortions, as they are illegal in some states. Also, journalists in places where there is no freedom of speech. Or transgender people, as they are threatened in some cultures. Speaking about organizations, many businesses also need privacy, because when you are doing business, your connections are being looked at. You need private communications with your service providers and other parties. In fact, all of us need privacy, because the internet, which we are using, is built on surveillance. Large corporations like Google, Meta, Apple, etc. provide free services in exchange for harvesting your personal data and selling them to third parties. That’s why personal data has become “the new oil of the digital era”. What has been done to protect us and why is it not enough Cryptography is widely used nowadays to hide data via end-to-end encryption, especially in the finance, healthcare, and communications industries. For example, WhatsApp has adopted the to encrypt the data and thus prevent third parties from having plain-text access to messages or calls. Also, SSL certificates have been made compulsory for sites to be considered trustworthy, so almost all the sites on the web use https instead of http. Signal protocol But encryption of data alone is not enough. Besides cookies (information about pages visited, date of the visit, and even passwords in some cases), which are collected by websites and stored on your hard drive, there is also metadata that needs to be protected. Metadata shows who is communicating with whom at what point, and hiding it is one problem that mixnets can handle with. What is a mixnet Internet is made of layers, suggests 7 layers, ranging from the physical to the application layer. The network layer is the place where all communications are made when you connect to the website or message your friend. There are packets that go through the network and reach destinations. They proceed on a very precise route that can be monitored. OSI model Mixnet is an overlay network, based on the existing network of packets. Using it, instead of sending packets on the internet in a normal way, we are sending them through another network, built on top of this system. On their way, the packets are encrypted, mixed, and proceed to a lot of different hubs on their way. In the end, no one knows what is happening, as the message is sent in a completely disorganized way. The first mixnets Surprisingly, mixnets are one of the oldest concepts on the Internet, dating back to 1981, when David Chaum, the famous engineer, published about them. a paper The first significant usage of mixnets, their first implementation is called Mixmaster, an anonymous remailer, which appeared around 2000. But it has a problem - using it opened doors to tons of spam. Spammers wanted to hide and find computers allowing them to send emails freely. To prevent this, the remailers, who were using mixnets, had to protect themselves. That’s why Adam Back, who was maintaining an anonymous remailer, invented proof-of-work, which is used today by Bitcoin and other blockchains. Nym vs VPN and Tor Nym is building a decentralized mixnet, providing privacy through anonymity tools. It’s important to note that Nym is not another VPN. VPNs are good for bypassing geolocalization, but bad in terms of privacy because VPN company stores data about you and your actions. Nym can’t collect this info, and it hides not only your IP, but metadata as well. It’s a network of computers, just sending packets to each other. They don’t record any packets, just mix and resend them. is also a mixnet, but it uses very old technology, and its design was meant to hide only IP addresses. Also, Tor does not protect you from “the god view”, as corporations may pay for the data collected by it. Tor Unlike Tor, Nym has created a token economy by introducing its utility token, which is used to pay for services. It also helps to fight against attackers, as there is a reputation system, incentivizing good actors and punishing the bad. If someone wants to attack Nym, they will need a large proportion of control in the form of tokens. Nym is like Tor in terms of legality and regulatory space, and Tor has not been subject to legal attacks so far. The thing is, the government may want to destroy privacy, but they need it, too. Think about military or health organizations - they all need their privacy to be protected. If you regulate Nym, you basically regulate something like VPNs, and if you regulate VPNs, many corporations will collapse, because VPNs protect their data. Does the government want to collapse corporations? I don’t think so.

Privacy protection and how Nym can help

GOGLOCAL

goglocal.live

-- employees

Since n.d.

COMPANY RANKING

GOGLOCAL

EVERGREEN INDEX #5080

Representing this company? Click here to claim and customize this page!

GoGlocal WIKI

Apply to get your Tech Company News Page live on HackerNoon.com today!

GOGLOCAL

goglocal.live

-- employees

Since n.d.

COMPANY RANKING

GOGLOCAL

EVERGREEN INDEX #5080

RELATED COMPANIESRANK

STORIES ABOUT GOGLOCAL

Representing this company? Click here to claim and customize this page!

GoGlocal WIKI

Apply to get your Tech Company News Page live on HackerNoon.com today!