Reflective Excel

Reading and writing Excel sheets made easy.

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Reflective Excel is a java library for mapping Excel sheets to Java Objects and vice-versa. It is designed to be versatile and simple to use. Under the hood, it uses Apache POI.

Some supported features:

• Tables with fixed column names.
• Tables with dynamic columns.
• Tables with grouped columns.
• [De]serialization of cell values from/to any java type.
• Styling the table/cell with custom fonts, background colors, and other.
• Reading and writing a table no matter the location in the sheet. For reading, auto-detection of the table is supported.
• Reading and writing a cell value at a fixed location in the sheet.
• For writing, providing a template Excel file.
• Multiple tables in one sheet.

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Development Setup

Prerequisites

• Java 17 or later.
• Project built with Maven.

Setting Up

In the pom.xml file of your project, add the following dependency:

<dependency>
    <groupId>?????</groupId>
    <artifactId>?????</artifactId>
    <version>0.1.0</version>
</dependency>

Examples

Reading an Excel sheet

Let's say we have the following table in the sheet (starting at cell "A1"):

ID	Description	Due date
1	Buy Milk	20/01/2024
2	Become productive	10/12/2099

The corresponding class will look as follows:

class TodoRow {

    @ExcelColumn("ID")
    private Integer id;
    
    @ExcelColumn("Description")
    private String description;
    
    @ExcelColumn("Due date")
    private Date dueDate;
}

Reading the rows:

List<TodoRow> rows = new ReflectiveExcelReader(excelFile).readRows(TodoRow.class);

This was the most trivial table example. Reflective Excel supports reading of more complex sheets and tables as well, including, but not limited to:

• Tables which start anywhere in the sheet.
• Columns which are dynamic. For example, columns which represent the days of a month.
• Grouped columns.
• Deserialization of the cell value to any java type.

For further instructions, see the documentation for the Reflective Excel Reader.

Writing an Excel sheet

Let's say we want to write the following table to the sheet:

ID	Description	Due date
1	Buy Milk	20/01/2024
2	Become productive	10/12/2099

The corresponding class will look as follows:

class TodoRow {

    @ExcelColumn("ID")
    private Integer id;

    @ExcelColumn("Description")
    private String description;

    @ExcelColumn("Due date")
    private LocalDate dueDate;

    // ... all args constructor
}

Writing the rows:

List<TodoRow> rows = List.of(
    new TodoRow(1, "Buy Milk", LocalDate.of(2024, 1, 20)),
    new TodoRow(2, "Become productive", LocalDate.of(2099, 12, 10))
);
new ReflectiveExcelWriter(outputFile).writeRows(rows, TodoRow.class);

This was the most trivial table example. Reflective Excel supports writing of more complex sheets and tables as well, including, but not limited to:

• Table and cell styling.
• Columns which are dynamic.
• Grouped columns.
• Serialization of any java type to a cell value.
• Tables which start anywhere in the sheet.

For further instructions, see the documentation for the Reflective Excel Writer.

Contributing

Feel free to provide improvement suggestions, feature ideas, report a bug or even ask a question by creating an issue.

License

This project is licensed under the terms of the MIT license.