### Start Local Development Server (English)

Source: https://github.com/apache/fesod/blob/main/website/README.md

Starts a local development server to preview the English version of the website. Changes are reflected live.

```bash
pnpm start
```

--------------------------------

### Start Local Development Server (Chinese)

Source: https://github.com/apache/fesod/blob/main/website/README.md

Starts a local development server to preview the Chinese version of the website. Changes are reflected live.

```bash
pnpm start --locale zh-cn
```

--------------------------------

### Start Local Development Server

Source: https://github.com/apache/fesod/blob/main/website/community/contribution/contribute-doc.md

Start the Docusaurus local development server. Specify the locale for different language versions.

```bash
# English
pnpm start

# Simplified Chinese
pnpm start --locale zh-cn
```

--------------------------------

### Install Dependencies with PNPM

Source: https://github.com/apache/fesod/blob/main/website/README.md

Installs project dependencies using PNPM. Ensure Node.js v20.0 or above is installed.

```bash
pnpm install
```

--------------------------------

### GPG Key Generation Interactive Prompt

Source: https://github.com/apache/fesod/blob/main/website/community/release/release-version.md

This is an example of the interactive prompt when generating a GPG key. It guides the user through setting key type, size, validity period, and user ID.

```text
gpg (GnuPG) 2.2.4; Copyright (C) 2017 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Please select what kind of key you want:
  (1) RSA and RSA (default)
  (2) DSA and Elgamal
  (3) DSA (sign only)
  (4) RSA (sign only)
Your selection? 1
RSA keys may be between 1024 and 4096 bits long.
What keysize do you want? (2048) 4096
Requested keysize is 4096 bits
Please specify how long the key should be valid.
        0 = key does not expire
     <n>  = key expires in n days
     <n>w = key expires in n weeks
     <n>m = key expires in n months
     <n>y = key expires in n years
Key is valid for? (0)
Key does not expire at all
Is this correct? (y/N) y

GnuPG needs to construct a user ID to identify your key.

Real name: (Set username) (Use Apache ID)
Email address: (Set email address) (Use Apache email)
Comment: (Fill in comments)
You selected this USER-ID:
   "Username (Comment) <Email Address>"

Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? O
You need a Passphrase to protect your secret key. (Set password) (Set password)

```

--------------------------------

### Image Path Example

Source: https://github.com/apache/fesod/blob/main/website/community/contribution/contribute-doc.md

Image files should be stored in the static/img directory and referenced using relative paths.

```markdown
[img](/img/docs/fill/listFill_file.png)
```

--------------------------------

### Write Data with Annotation Styles

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/write/style.md

This example demonstrates how to write data to an Excel file using the styles defined via annotations in the POJO class.

```java
@Test
public void annotationStyleWrite() {
    String fileName = "annotationStyleWrite" + System.currentTimeMillis() + ".xlsx";

    FesodSheet.write(fileName, DemoStyleData.class)
            .sheet()
            .doWrite(data());
}
```

--------------------------------

### Markdown Link Example

Source: https://github.com/apache/fesod/blob/main/website/community/contribution/contribute-doc.md

Use file paths with the .md extension for internal links.

```markdown
[Example](docs/quickstart/example.md)
```

--------------------------------

### Start Vote Email Template

Source: https://github.com/apache/fesod/blob/main/website/community/pmc/nominate-committer.md

Use this template to start the official voting process for a nominated committer. Include a link to the discussion thread and specify voting instructions.

```text
[VOTE] Add candidate ${CANDIDATE_NAME} as a new committer
```

```text
Hi all,
  
This is a VOTE to add candidate ${CANDIDATE_NAME} (GitHub id: ${CANDIDATE_GITHUB_ID}) as a new committer.

This has been discussed here: [Link to DISCUSS thread on lists.apache.org] If you have more to 
add to the discussion, please do so there, rather than in this VOTE thread.

Please vote accordingly:

[ +1 ] Yes, add this committer
[  0 ] Abstain
[ -1 ] No, do not add this committer

Voting ends one week from today, i.e. midnight UTC on YYYY-MM-DD
https://www.timeanddate.com/counters/customcounter.html?year=YYYY&month=MM&day=DD

See voting guidelines at
https://community.apache.org/pmc/adding-committers.html
```

--------------------------------

### Write Excel with Custom Merge Strategy

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/write/merge.md

This example shows how to register and use a `CustomMergeStrategy` when writing an Excel file. This allows for complex, data-driven cell merging.

```java
import com.fesod.FesodSheet;
import org.junit.jupiter.api.Test;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class CustomMergeTest {

    @Test
    public void customMergeWrite() {
        String fileName = "customMergeWrite" + System.currentTimeMillis() + ".xlsx";
        FesodSheet.write(fileName, DemoData.class)
            .registerWriteHandler(new CustomMergeStrategy())
            .sheet()
            .doWrite(data());
    }

    // Assuming DemoData is a placeholder class for demonstration
    public static class DemoData {
        // ... fields ...
    }

    private List<DemoData> data() {
        List<DemoData> list = new ArrayList<>();
        // ... populate data ...
        return list;
    }
}
```

--------------------------------

### Write Spreadsheet Data with Fesod

Source: https://github.com/apache/fesod/blob/main/website/docs/quickstart/example.md

Prepare data using a sample data class and write it to a spreadsheet file. This example demonstrates creating a 'Template' sheet and performing the write operation.

```java
// Sample data class
public class DemoData {
    @ExcelProperty("String Title")
    private String string;
    @ExcelProperty("Date Title")
    private Date date;
    @ExcelProperty("Number Title")
    private Double doubleData;
    @ExcelIgnore
    private String ignore;
}

// Prepare data to write
private static List<DemoData> data() {
    List<DemoData> list = new ArrayList<>();
    for (int i = 0; i < 10; i++) {
        DemoData data = new DemoData();
        data.setString("String" + i);
        data.setDate(new Date());
        data.setDoubleData(0.56);
        list.add(data);
    }
    return list;
}

public static void main(String[] args) {
    String fileName = "demo.xlsx";
    // Create a "Template" sheet and write data
    FesodSheet.write(fileName, DemoData.class).sheet("Template").doWrite(data());
}
```

--------------------------------

### Write Excel with Strategy-Based Merging

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/write/merge.md

This example demonstrates writing to an Excel file using a `LoopMergeStrategy` to merge every 2 rows in column 0. This strategy is flexible and can be configured at runtime.

```java
import com.fesod.FesodSheet;
import com.fesod.write.handler.impl.LoopMergeStrategy;
import org.junit.jupiter.api.Test;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

public class StrategyMergeTest {

    @Test
    public void strategyMergeWrite() {
        String fileName = "strategyMergeWrite" + System.currentTimeMillis() + ".xlsx";

        // Merge every 2 rows in column 0
        LoopMergeStrategy strategy = new LoopMergeStrategy(2, 0);
        FesodSheet.write(fileName, DemoData.class)
            .registerWriteHandler(strategy)
            .sheet()
            .doWrite(data());
    }

    // Assuming DemoData is a placeholder class for demonstration
    public static class DemoData {
        // ... fields ...
    }

    private List<DemoData> data() {
        List<DemoData> list = new ArrayList<>();
        // ... populate data ...
        return list;
    }
}
```

--------------------------------

### Write Complex Headers to Excel

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/write/head.md

This example demonstrates how to write data with complex headers defined in a POJO class to an Excel file using Fesod.

```java
@Test
public void complexHeadWrite() {
    String fileName = "complexHeadWrite" + System.currentTimeMillis() + ".xlsx";
    FesodSheet.write(fileName, ComplexHeadData.class)
            .sheet()
            .doWrite(data());
}
```

--------------------------------

### Write Spreadsheet Data with Apache Fesod

Source: https://github.com/apache/fesod/blob/main/README.md

Example of creating a spreadsheet and writing data using FesodSheet. The DemoData class should be defined with @ExcelProperty and @ExcelIgnore annotations as needed.

```java
// Sample data class
public class DemoData {

    @ExcelProperty("String Title")
    private String string;

    @ExcelProperty("Date Title")
    private Date date;

    @ExcelProperty("Number Title")
    private Double doubleData;

    @ExcelIgnore
    private String ignore;
}

// Prepare data to write
private static List<DemoData> data() {
    List<DemoData> list = new ArrayList<>();
    for (int i = 0; i < 10; i++) {
        DemoData data = new DemoData();
        data.setString("String" + i);
        data.setDate(new Date());
        data.setDoubleData(0.56);
        list.add(data);
    }
    return list;
}

public static void main(String[] args) {
    String fileName = "demo.xlsx";
    // Create a "Template" sheet and write data
    FesodSheet.write(fileName, DemoData.class).sheet("Template").doWrite(data());
}
```

--------------------------------

### Example Commit Messages

Source: https://github.com/apache/fesod/blob/main/website/community/contribution/commit-format.md

Illustrates the correct format for various types of commit messages, such as documentation updates, new features, bug fixes, refactoring, style changes, tests, chores, and dependency updates.

```git
docs: update README.md
```

```git
feature: support for xxx
```

```git
fix: fix NPE in the A class
```

```git
refactor: optimise data processing logic
```

```git
style: update code style
```

```git
test: add new test cases
```

```git
chore: improve issue template
```

```git
dependency: upgrade poi version to 5.4.1
```

--------------------------------

### Custom Cell Styles with WriteHandler

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/help/faq.md

Customize cell styles during writing by implementing the WriteHandler interface. This example shows how to set a red background for content cells.

```java
public class CustomCellStyleWriteHandler extends AbstractCellStyleStrategy {
    
      @Override
      public int order() {
          // Customize the execution order
          return OrderConstant.SHEET_ORDER;
      }

      @Override
      protected void setHeadCellStyle(CellWriteHandlerContext context) {
          // Customize the head cell style
      }
  
      @Override
      protected void setContentCellStyle(Cell cell, Head head, Integer relativeRowIndex) {
          CellStyle style = cell.getSheet().getWorkbook().createCellStyle();
          style.setFillForegroundColor(IndexedColors.RED.getIndex());
          style.setFillPattern(FillPatternType.SOLID_FOREGROUND);
          cell.setCellStyle(style);
      }
  }
```

--------------------------------

### Set Custom Cell Style

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/help/core-class.md

Implement CellWriteHandler to customize cell styles. This example sets the background to yellow and font to blue for content cells.

```java
import org.apache.commons.lang3.BooleanUtils;
import com.fesod.sheet.handler.CellWriteHandler;
import com.fesod.sheet.handler.CellWriteHandlerContext;
import com.fesod.sheet.write.WriteCellData;
import com.fesod.sheet.write.WriteCellStyle;
import com.fesod.sheet.write.WriteFont;
import com.fesod.sheet.write.style.FillPatternType;
import com.fesod.sheet.write.style.IndexedColors;
import lombok.extern.slf4j.Slf4j;

@Slf4j
public class CustomCellStyleHandler implements CellWriteHandler {

    @Override
    public void afterCellDispose(CellWriteHandlerContext context) {
        // Ensure only content cells (not headers) are operated on
        if (BooleanUtils.isNotTrue(context.getHead())) {
            WriteCellData<?> cellData = context.getFirstCellData();
            WriteCellStyle style = cellData.getOrCreateStyle();

            // Set background color to yellow
            style.setFillForegroundColor(IndexedColors.YELLOW.getIndex());
            style.setFillPatternType(FillPatternType.SOLID_FOREGROUND);

            // Set font color to blue
            WriteFont font = new WriteFont();
            font.setColor(IndexedColors.BLUE.getIndex());
            style.setWriteFont(font);

            log.info("Style set: Row {}, Column {}", context.getRowIndex(), context.getColumnIndex());
        }
    }
}
```

```java
import org.junit.jupiter.api.Test;
import com.fesod.sheet.FesodSheet;
import com.fesod.sheet.demo.DemoData;

public class ExcelWriteTest {

    @Test
    public void customCellStyleWrite() {
        String fileName = "customCellStyleWrite.xlsx";

        FesodSheet.write(fileName, DemoData.class)
                .registerWriteHandler(new CustomCellStyleHandler())
                .sheet("Custom Style")
                .doWrite(data());
    }

    private Object[][] data() {
        return new Object[][]{
                // Add your demo data here
        };
    }
}
```

--------------------------------

### Import GPG KEYS

Source: https://github.com/apache/fesod/blob/main/website/community/release/verify-release.md

Download the KEYS file from the distribution directory and import it into your local GPG keyring. This is necessary for signature verification.

```shell
# Download KEYS
curl https://dist.apache.org/repos/dist/dev/incubator/fesod/KEYS > KEYS

# Import KEYS locally
gpg --import KEYS
```

--------------------------------

### Import GPG Keys

Source: https://github.com/apache/fesod/blob/main/website/docs/download.md

Import the project release KEYS file to your GPG keyring to enable signature verification.

```bash
gpg --import KEYS
```

--------------------------------

### Prepare Release Branch and Tag

Source: https://github.com/apache/fesod/blob/main/website/community/release/release-version.md

Commands to checkout the main branch, pull updates, create a GPG signed tag, and push it to the remote repository.

```bash
# 1. Switch to the main branch and update
git checkout main
git pull

# 2. Create a GPG signed Tag
# Note: Ensure the content in -m is accurate
git tag -s 2.0.0-incubating-rc1 -m "release: release for 2.0.0-incubating RC1"

# 3. Push the Tag to the remote repository
git push git@github.com:apache/fesod.git 2.0.0-incubating-rc1
```

--------------------------------

### Apply Code Formatting with Spotless

Source: https://github.com/apache/fesod/blob/main/website/community/contribution/contribute-code.md

Automatically format your code before submitting changes by running the Spotless Maven plugin.

```bash
mvn spotless:apply
```

--------------------------------

### Upload Source Package to SVN

Source: https://github.com/apache/fesod/blob/main/website/community/release/release-version.md

Checkout the SVN dev repository, create a version directory, copy release artifacts, and commit to SVN.

```bash
# 1. Checkout SVN dev repository
svn co https://dist.apache.org/repos/dist/dev/incubator/fesod/
cd fesod-dev

# 2. Create version directory
mkdir 2.0.0-incubating-rc1
cd 2.0.0-incubating-rc1

# 3. Copy files (assuming files are in the parent directory)
cp ../../apache-fesod-2.0.0-incubating-src.tar.gz .
cp ../../apache-fesod-2.0.0-incubating-src.tar.gz.asc .
cp ../../apache-fesod-2.0.0-incubating-src.tar.gz.sha512 .

# 4. Commit to SVN
cd ..
svn add 2.0.0-incubating-rc1
svn commit -m "Add 2.0.0-incubating-rc1 source release"
```

--------------------------------

### Configure CSV Null String

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/read/csv.md

Specify a string that should be interpreted as a null value during CSV parsing. This example maps the string 'N/A' to null.

```java
@Test
public void nullStringDemo() {
    String csvFile = "path/to/your.csv";
    List<DemoData> dataList = FesodSheet.read(csvFile, DemoData.class, new DemoDataListener())
            .csv()
            .nullString("N/A")
            .doReadSync();
}
```

--------------------------------

### Build Static Website

Source: https://github.com/apache/fesod/blob/main/website/README.md

Generates static content into the `build` directory, ready for deployment on any static hosting service.

```bash
pnpm build
```

--------------------------------

### Insert Comment in Header Cell

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/help/core-class.md

Implement RowWriteHandler to insert comments. This example adds a comment to the first row, second column of the header.

```java
import org.apache.commons.lang3.BooleanUtils;
import com.fesod.sheet.handler.RowWriteHandler;
import com.fesod.sheet.handler.RowWriteHandlerContext;
import org.apache.poi.ss.usermodel.Comment;
import org.apache.poi.ss.usermodel.Drawing;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.xssf.usermodel.XSSFClientAnchor;
import org.apache.poi.xssf.usermodel.XSSFRichTextString;
import lombok.extern.slf4j.Slf4j;

@Slf4j
public class CommentRowWriteHandler implements RowWriteHandler {

    @Override
    public void afterRowDispose(RowWriteHandlerContext context) {
        if (BooleanUtils.isTrue(context.getHead())) {
            Sheet sheet = context.getWriteSheetHolder().getSheet();
            Drawing<?> drawing = sheet.createDrawingPatriarch();

            // Create a comment
            Comment comment = drawing.createCellComment(new XSSFClientAnchor(0, 0, 0, 0, (short) 1, 0, (short) 2, 1));
            comment.setString(new XSSFRichTextString("This is a comment"));
            sheet.getRow(0).getCell(1).setCellComment(comment);

            log.info("Comment inserted at first row, second column");
        }
    }
}
```

```java
import org.junit.jupiter.api.Test;
import com.fesod.sheet.FesodSheet;
import com.fesod.sheet.demo.DemoData;

public class ExcelWriteTest {

    @Test
    public void commentWrite() {
        String fileName = "commentWrite.xlsx";

        FesodSheet.write(fileName, DemoData.class)
                .registerWriteHandler(new CommentRowWriteHandler())
                .sheet("Insert Comment")
                .doWrite(data());
    }

    private Object[][] data() {
        return new Object[][]{
                // Add your demo data here
        };
    }
}
```

--------------------------------

### Configure CSV Delimiter

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/read/csv.md

Set a custom delimiter for CSV files when the default comma is not used. This example uses a Unicode empty character as the delimiter.

```java
@Test
public void delimiterDemo() {
    String csvFile = "path/to/your.csv";
    List<DemoData> dataList = FesodSheet.read(csvFile, DemoData.class, new DemoDataListener())
            .csv()
            .delimiter(CsvConstant.UNICODE_EMPTY)
            .doReadSync();
}
```

--------------------------------

### Compile Project with Maven

Source: https://github.com/apache/fesod/blob/main/website/community/contribution/contribute-code.md

Compile the project using Maven. Use '-DskipTests' to skip unit tests and '-T 1C' for parallel build to speed up the process.

```bash
mvn clean install -DskipTests
```

--------------------------------

### Deploy Maven Artifacts for Release

Source: https://github.com/apache/fesod/blob/main/website/community/release/release-version.md

Use this Maven command to clean, deploy, and skip tests for the release. Ensure GPG signing is enabled.

```bash
mvn clean deploy -Papache-release -DskipTests -Dgpg.skip=false
```

--------------------------------

### Configure Maven Settings for Release

Source: https://github.com/apache/fesod/blob/main/website/community/release/release-version.md

Add key information to your Maven settings.xml file for signed releases, including GPG key details and repository URLs.

```xml
<settings>
    <profiles>
        <profile>
            <id>signed_release</id>
            <properties>
                <mavenExecutorId>forked-path</mavenExecutorId>
                <gpg.keyname>yourKeyName</gpg.keyname>
          <deploy.url>https://dist.apache.org/repos/dist/dev/incubator/fesod/</deploy.url>
            </properties>
        </profile>
    </profiles>
    <servers>
        <server>
            <id>apache.snapshots.https</id>
            <username>yourApacheID</username>
            <password>yourApachePassword</password>
        </server>
        <server>
            <id>apache.releases.https</id>
            <username>yourApacheID</username>
            <password>yourApachePassword</password>
        </server>
        <server>
            <id>gpg.passphrase</id>
            <passphrase>yourKeyPassword</passphrase>
        </server>
    </servers>
</settings>
```

--------------------------------

### Download Release Artifacts

Source: https://github.com/apache/fesod/blob/main/website/community/release/verify-release.md

Download the release candidate artifacts. The SVN checkout method is recommended as it includes the KEYS file.

```shell
# Option 1: SVN checkout (Recommended, includes KEYS file)
svn co https://dist.apache.org/repos/dist/dev/incubator/fesod/${RELEASE_VERSION}-${RC_VERSION}/ fesod-dist-dev
```

```shell
# Option 2: Wget individual files
wget https://dist.apache.org/repos/dist/dev/incubator/fesod/${RELEASE_VERSION}-${RC_VERSION}/apache-fesod-${RELEASE_VERSION}-src.tar.gz
```

--------------------------------

### Add Dropdown List to Cells

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/help/core-class.md

Implement SheetWriteHandler to add data validation dropdown lists. This example creates a dropdown for the first column of the first two rows.

```java
import com.fesod.sheet.handler.SheetWriteHandler;
import com.fesod.sheet.handler.SheetWriteHandlerContext;
import org.apache.poi.ss.usermodel.DataValidation;
import org.apache.poi.ss.usermodel.DataValidationConstraint;
import org.apache.poi.ss.usermodel.DataValidationHelper;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.util.CellRangeAddressList;
import lombok.extern.slf4j.Slf4j;

@Slf4j
public class DropdownSheetWriteHandler implements SheetWriteHandler {

    @Override
    public void afterSheetCreate(SheetWriteHandlerContext context) {
        Sheet sheet = context.getWriteSheetHolder().getSheet();

        // Create dropdown list range
        CellRangeAddressList range = new CellRangeAddressList(1, 2, 0, 0);
        DataValidationHelper helper = sheet.getDataValidationHelper();
        DataValidationConstraint constraint = helper.createExplicitListConstraint(new String[]{"Option 1", "Option 2"});
        DataValidation validation = helper.createValidation(constraint, range);
        sheet.addValidationData(validation);

        log.info("Dropdown list added to the first column of the first two rows");
    }
}
```

```java
import org.junit.jupiter.api.Test;
import com.fesod.sheet.FesodSheet;
import com.fesod.sheet.demo.DemoData;

public class ExcelWriteTest {

    @Test
    public void dropdownWrite() {
        String fileName = "dropdownWrite.xlsx";

        FesodSheet.write(fileName, DemoData.class)
                .registerWriteHandler(new DropdownSheetWriteHandler())
                .sheet("Add Dropdown")
                .doWrite(data());
    }

    private Object[][] data() {
        return new Object[][]{
                // Add your demo data here
        };
    }
}
```

--------------------------------

### Getting Approximate Total Rows

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/help/faq.md

Obtain an approximate total row count for a sheet within a listener using `context.readSheetHolder().getApproximateTotalRowNumber()`. This is useful for progress tracking or estimations.

```java
@Override
public void doAfterAllAnalysed(AnalysisContext context) {
    int totalRows = context.readSheetHolder().getApproximateTotalRowNumber();
    System.out.println("Total rows: " + totalRows);
}
```

--------------------------------

### Read Spreadsheet Data with Fesod

Source: https://github.com/apache/fesod/blob/main/website/docs/quickstart/example.md

Implement the ReadListener interface to process data row by row during spreadsheet reading. This example shows how to define a listener and initiate the read operation.

```java
// Implement the ReadListener interface to set up operations for reading data
public class DemoDataListener implements ReadListener<DemoData> {
    @Override
    public void invoke(DemoData data, AnalysisContext context) {
        System.out.println("Parsed a data entry" + JSON.toJSONString(data));
    }

    @Override
    public void doAfterAllAnalysed(AnalysisContext context) {
        System.out.println("All data parsed!");
    }
}

public static void main(String[] args) {
    String fileName = "demo.xlsx";
    // Read file
    FesodSheet.read(fileName, DemoData.class, new DemoDataListener()).sheet().doRead();
}
```

--------------------------------

### Run Markdown Lint Check

Source: https://github.com/apache/fesod/blob/main/website/community/contribution/contribute-doc.md

Check document formatting using markdownlint-cli2. Navigate to the website directory first.

```bash
cd website

pnpm md-lint
```

--------------------------------

### Build Fesod from Source

Source: https://github.com/apache/fesod/blob/main/website/community/release/release-version.md

Command to build the Apache Fesod project from source using Maven wrapper, skipping tests. Requires JDK 8+ and Apache Maven 3.6.0+.

```bash
./mvnw clean package -DskipTests
```

--------------------------------

### Configure CSV Record Separator

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/read/csv.md

Define the record separator for CSV files, which can vary by operating system. This example sets the record separator to LF, commonly used in Unix/Linux systems.

```java
@Test
public void recordSeparatorDemo() {
    String csvFile = "path/to/your.csv";
    List<DemoData> dataList = FesodSheet.read(csvFile, DemoData.class, new DemoDataListener())
            .csv()
            .recordSeparator(CsvConstant.LF)
            .doReadSync();
}
```

--------------------------------

### Override onException Method in Listener

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/read/exception.md

Override the onException method to handle exceptions during data reading. This example shows how to log general exceptions and specifically catch ExcelDataConvertException for detailed error information.

```java
import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.event.AnalysisEventListener;
import com.alibaba.excel.exception.ExcelDataConvertException;
import lombok.extern.slf4j.Slf4j;

@Slf4j
public class DemoExceptionListener extends AnalysisEventListener<ExceptionDemoData> {
    @Override
    public void onException(Exception exception, AnalysisContext context) {
        log.error("Failed: {}", exception.getMessage());
        if (exception instanceof ExcelDataConvertException) {
            ExcelDataConvertException ex = (ExcelDataConvertException) exception;
            log.error("Row {}, Column {} exception, data: {}", ex.getRowIndex(), ex.getColumnIndex(), ex.getCellData());
        }
    }

    @Override
    public void invoke(ExceptionDemoData data, AnalysisContext context) {}

    @Override
    public void doAfterAllAnalysed(AnalysisContext context) {}
}
```

--------------------------------

### Read Spreadsheet Data with Apache Fesod

Source: https://github.com/apache/fesod/blob/main/README.md

Example of reading spreadsheet data using FesodSheet. Implement the ReadListener interface to process each row. Ensure DemoData class is defined with appropriate annotations.

```java
// Implement the ReadListener interface to set up operations for reading data
public class DemoDataListener implements ReadListener<DemoData> {

    @Override
    public void invoke(DemoData data, AnalysisContext context) {
        System.out.println("Parsed a data entry" + JSON.toJSONString(data));
    }

    @Override
    public void doAfterAllAnalysed(AnalysisContext context) {
        System.out.println("All data parsed!");
    }
}

public static void main(String[] args) {
    String fileName = "demo.xlsx";
    // Read spreadsheet file
    FesodSheet.read(fileName, DemoData.class, new DemoDataListener()).sheet().doRead();
}
```

--------------------------------

### Writing Excel with Merging

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/write/extra.md

Demonstrates how to write Excel files using both annotation-based and custom merge strategies. Ensure data is provided to the doWrite method.

```java
@Test
public void mergeWrite() {
    String fileName = "mergeWrite" + System.currentTimeMillis() + ".xlsx";

    // Annotation approach
    FesodSheet.write(fileName, DemoMergeData.class)
        .sheet("合并示例")
        .doWrite(data());

    // Custom merge strategy
    FesodSheet.write(fileName, DemoData.class)
        .registerWriteHandler(new CustomMergeStrategy())
        .sheet("自定义合并")
        .doWrite(data());
}
```

--------------------------------

### Verify Release Artifacts

Source: https://github.com/apache/fesod/blob/main/website/community/release/release-version.md

Verify the integrity and authenticity of the downloaded source package using GPG and SHA512 checksums.

```bash
gpg --verify apache-fesod-2.0.0-incubating-src.tar.gz.asc apache-fesod-2.0.0-incubating-src.tar.gz
sha512sum -c apache-fesod-2.0.0-incubating-src.tar.gz.sha512
```

--------------------------------

### Read Merged Cells with Listener - Java

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/read/extra.md

Implement a ReadListener to process merged cell range information. The `extra` method checks for `CellExtraTypeEnum.MERGE` and logs the start and end row indices of the merged area.

```java
@Slf4j
public class DemoMergeExtraListener implements ReadListener<DemoData> {
    @Override
    public void invoke(DemoData data, AnalysisContext context) {}

    @Override
    public void doAfterAllAnalysed(AnalysisContext context) {}

    @Override
    public void extra(CellExtra extra, AnalysisContext context) {
        log.info("Read extra information: {}", JSON.toJSONString(extra));
        if(CellExtraTypeEnum.MERGE == extra.getType()) {
            log.info("Merged cell range: {} - {}", extra.getFirstRowIndex(), extra.getLastRowIndex());
        }
    }
}
```

--------------------------------

### Custom Merge Strategy Implementation

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/write/merge.md

Implement `AbstractMergeStrategy` to define complex merging logic based on data content or custom rules. This example merges cells in column 0 every two rows.

```java
import com.fesod.write.handler.AbstractMergeStrategy;
import com.fesod.write.handler.Head;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.util.CellRangeAddress;

public class CustomMergeStrategy extends AbstractMergeStrategy {
    @Override
    protected void merge(Sheet sheet, Cell cell, Head head, Integer relativeRowIndex) {
        if (relativeRowIndex != null && relativeRowIndex % 2 == 0 && head.getColumnIndex() == 0) {
            // Note: +1 assumes a single header row. For multi-row headers, use cell.getRowIndex() instead.
            int startRow = relativeRowIndex + 1;
            int endRow = startRow + 1;
            sheet.addMergedRegion(new CellRangeAddress(startRow, endRow, 0, 0));
        }
    }
}
```

--------------------------------

### Compile Source Code

Source: https://github.com/apache/fesod/blob/main/website/community/release/verify-release.md

Compile the source code using Maven, skipping tests. This verifies that the code compiles successfully and downloads necessary dependencies.

```shell
# This may take time depending on network to download dependencies
./mvnw clean install -DskipTests
```

--------------------------------

### POJO with Per-Field Converter Annotation

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/write/converter.md

Annotate a POJO field with `@ExcelProperty` and specify a custom converter class to apply specific data transformations for that field during Excel writing. This example applies `CustomStringStringConverter` to the 'string' field.

```java
@Getter
@Setter
@EqualsAndHashCode
public class ConverterData {
    @ExcelProperty(value = "String Title", converter = CustomStringStringConverter.class)
    private String string;

    @DateTimeFormat("yyyy-MM-dd HH:mm:ss")
    @ExcelProperty("Date Title")
    private Date date;

    @NumberFormat("#.#%\%")
    @ExcelProperty("Number Title")
    private Double doubleData;
}
```

--------------------------------

### Verify GPG Signature

Source: https://github.com/apache/fesod/blob/main/website/docs/download.md

Verify the GPG signature of the downloaded source release using the .asc signature file.

```bash
gpg --verify apache-fesod-X.X.X-incubating-src.tar.gz.asc apache-fesod-X.X.X-incubating-src.tar.gz
```

--------------------------------

### Complex Fill with Large Data and WriteTable

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/fill/fill.md

Optimizes performance for large datasets by placing the template list at the last row and using `WriteTable` for subsequent data. This example fills list data, variables, and statistical information.

```java
@Test
public void complexFillWithTable() {
    String templateFileName = "path/to/complexFillWithTable.xlsx";

    try (ExcelWriter writer = FesodSheet.write("complexFillWithTable.xlsx").withTemplate(templateFileName).build()) {
        WriteSheet writeSheet = FesodSheet.writerSheet().build();

        // Fill list data
        writer.fill(data(), writeSheet);

        // Fill list data
        Map<String, Object> map = new HashMap<>();
        map.put("date", "2024年11月20日");
        writer.fill(map, writeSheet);

        // Fill statistical information
        List<List<String>> totalList = new ArrayList<>();
        totalList.add(Arrays.asList(null, null, null, "统计: 1000"));
        writer.write(totalList, writeSheet);
    }
}
```

--------------------------------

### Upload Public Key to Server

Source: https://github.com/apache/fesod/blob/main/website/community/release/release-version.md

Uploads your public GPG key to the specified public key server. This makes your key available for others to retrieve and verify signatures.

```bash
[root@localhost gpgtest]# gpg --keyserver keys.openpgp.org --send-key XXXXXXXX
gpg: sending key XXXXXXXX to hkp server keys.openpgp.org
```

--------------------------------

### Simple Fill with Object or Map

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/fill/fill.md

Demonstrates filling data into an Excel template using either a POJO or a Map. Specify the output file and the template file path.

```java
@Test
public void simpleFill() {
    String templateFileName = "path/to/simple.xlsx";

    // Approach 1: Fill based on object
    FillData fillData = new FillData();
    fillData.setName("张三");
    fillData.setNumber(5.2);
    FesodSheet.write("simpleFill.xlsx")
            .withTemplate(templateFileName)
            .sheet()
            .doFill(fillData);

    // Approach 2: Fill based on Map
    Map<String, Object> map = new HashMap<>();
    map.put("name", "张三");
    map.put("number", 5.2);
    FesodSheet.write("simpleFillMap.xlsx")
            .withTemplate(templateFileName)
            .sheet()
            .doFill(map);
}
```

--------------------------------

### Register Custom Converter for Global Write Operation in Java

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/advanced/custom-converter.md

Register a custom converter globally using the Fesod builder to apply it to all fields of the supported type during write operations. This example demonstrates registering `CustomStringStringConverter` before writing data.

```java
@Test
public void customConverterWrite() {
    String fileName = "customConverterWrite" + System.currentTimeMillis() + ".xlsx";

    FesodSheet.write(fileName, DemoData.class)
        .registerConverter(new CustomStringStringConverter())
        .sheet()
        .doWrite(data());
}
```

--------------------------------

### Verify SHA-512 Checksum (Linux)

Source: https://github.com/apache/fesod/blob/main/website/docs/download.md

Verify the SHA-512 checksum of the downloaded source release using the .sha512 checksum file on Linux.

```bash
sha512sum -c apache-fesod-X.X.X-incubating-src.tar.gz.sha512
```

--------------------------------

### Register Custom Converter for Global Read Operation in Java

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/advanced/custom-converter.md

Register a custom converter globally using the Fesod builder to apply it to all fields of the supported type during read operations. This example shows how to register `CustomStringStringConverter` before reading data from an Excel file.

```java
@Test
public void customConverterRead() {
    String fileName = "path/to/demo.xlsx";

    FesodSheet.read(fileName, DemoData.class, new DemoDataListener())
        .registerConverter(new CustomStringStringConverter())
        .sheet()
        .doRead();
}
```

--------------------------------

### Implement Custom String Converter in Java

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/advanced/custom-converter.md

Implement the `Converter` interface to define custom logic for transforming String data between Java and Excel formats. This example shows how to support String type for both Java and Excel and provides custom conversion logic.

```java
public class CustomStringStringConverter implements Converter<String> {
    @Override
    public Class<?> supportJavaTypeKey() {
        return String.class;
    }

    @Override
    public CellDataTypeEnum supportExcelTypeKey() {
        return CellDataTypeEnum.STRING;
    }

    @Override
    public String convertToJavaData(ReadConverterContext<?> context) {
        return "Custom: " + context.getReadCellData().getStringValue();
    }

    @Override
    public WriteCellData<?> convertToExcelData(WriteConverterContext<String> context) {
        return new WriteCellData<>("Custom: " + context.getValue());
    }
}
```

--------------------------------

### Read Excel with Exception Handling

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/read/exception.md

Demonstrates how to initiate an Excel read operation using Fesod, specifying the file, data class, and a custom exception listener to handle potential errors.

```java
import org.junit.Test;

public class DemoTest {
    @Test
    public void exceptionRead() {
        String fileName = "path/to/demo.xlsx";

        FesodSheet.read(fileName, ExceptionDemoData.class, new DemoExceptionListener())
                .sheet()
                .doRead();
    }
}
```

--------------------------------

### Batch Writing Large Excel Files with Compressed Temp Files

Source: https://github.com/apache/fesod/blob/main/website/docs/sheet/advanced/large-file.md

Write large Excel files in batches using Fesod's ExcelWriter. This example demonstrates enabling compressed temporary files for memory optimization, which is useful in disk-constrained environments. Tune the batch size based on your row width and available memory.

```java
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.streaming.SXSSFWorkbook;
import org.junit.jupiter.api.Test;

import com.esotericsoftware.kryo.util.Util;
import com.esotericsoftware.minlog.Log;
import com.fesod.sheet.ExcelWriter;
import com.fesod.sheet.FesodSheet;
import com.fesod.sheet.WriteSheet;
import com.fesod.sheet.handler.WorkbookWriteHandler;
import com.fesod.sheet.handler.WorkbookWriteHandlerContext;

public class LargeFileTest {

    @Test
    public void largeFileWrite() {
        String fileName = "largeFile" + System.currentTimeMillis() + ".xlsx";

        try (ExcelWriter excelWriter = FesodSheet.write(fileName, DemoData.class)
                .registerWriteHandler(new WorkbookWriteHandler() {
                    @Override
                    public void afterWorkbookCreate(WorkbookWriteHandlerContext context) {
                        Workbook workbook = context.getWriteWorkbookHolder().getWorkbook();
                        if (workbook instanceof SXSSFWorkbook) {
                            ((SXSSFWorkbook) workbook).setCompressTempFiles(true);
                        }
                    }
                })
                .build()) {
            WriteSheet writeSheet = FesodSheet.writerSheet("Template").build();
            // Write data in batches — each data() call returns one batch
            for (int i = 0; i < 1000; i++) {
                excelWriter.write(data(), writeSheet);
            }
        }
    }

    // Dummy methods for compilation
    private Object data() {
        return new Object();
    }

    private static class DemoData {
        // Dummy class
    }
}
```

--------------------------------

### Verify SHA512 Checksum (Windows)

Source: https://github.com/apache/fesod/blob/main/website/community/release/verify-release.md

Verify the SHA512 checksum of the source package on Windows using the certUtil command.

```shell
certUtil -hashfile apache-fesod-${RELEASE_VERSION}-src.tar.gz SHA512
```