EasyExcel Dynamic Columns [Application Scenario] Export Excel Files

# 1. Introduction

## 1.1 What is EasyExcel?

In the process of handling Excel files, EasyExcel is an open-source Java library for server-side Excel operations, featuring ease of use and efficiency, which allows for rapid reading and writing of Excel files. It offers a rich set of APIs, supporting the import of Excel while exporting dynamic columns as needed, facilitating development when dynamic column processing is required.

## 1.2 Why is dynamic column export needed for Excel files?

In actual project development, there is sometimes a need to dynamically generate Excel files with varying numbers of columns based on different business requirements, such as exporting different columns as reports based on various query conditions. Traditional static template methods may not be able to meet the needs of such flexibility, making dynamic column export a common requirement in development.

## 1.3 Overview of this article

This article will first introduce the basics of the EasyExcel library, including its definition, features, and installation configuration. Next, we will delve into the principles of dynamic column export for Excel files and demonstrate how to use EasyExcel to dynamically export data to Excel files through examples. Then, we will explore the application scenarios of dynamic column export for Excel files in various industries, and provide you with a practical guide on how to use EasyExcel for dynamic column export. Finally, we will summarize the advantages, limitations, and future development trends of EasyExcel's dynamic column export. We hope this article will help you better understand and apply the technology of dynamic column export for Excel files.

# 2. Introduction to EasyExcel

In this chapter, we will introduce the basic information of the EasyExcel library, including what EasyExcel is, its main features, and how to install and configure the library. Let's dive deep into EasyExcel together.

# 3. Principles of Dynamic Column Export for Excel Files

In this chapter, we will delve into the reasons for using dynamic column export for Excel files and introduce the principles behind this functionality. We will also provide an example demonstrating how to use EasyExcel to dynamically export data to an Excel file.

#### 3.1 Why use dynamic column export for Excel files?

Under normal circumstances, the columns of statically exported Excel files are fixed, and when the data source changes, the export template needs to be modified. This requires maintaining multiple templates and results in cumbersome operations. In contrast, dynamic column export for Excel files can automatically adjust the number and content of columns based on the dynamic changes in the data source, providing greater flexibility and efficiency.

#### 3.2 Introduction to the principles of dynamic column export for Excel files

With EasyExcel, we can dynamically generate Excel files and dynamically adjust columns based on fields in the data source. In essence, this involves dynamically generating Excel headers and data based on the dynamic changes in the data. This way, when the data structure changes, there is no need to modify code or export templates.

// Pseudo-code example
for (int i = 0; i < data.size(); i++) {
    Row row = sheet.createRow(i);
    for (int j = 0; j < columnHeader.size(); j++)