Tagged articles

Apache POI

27 articles · Page 1 of 1

Jun 16, 2026 · Backend Development

Avoid OOM: Stream Massive Excel Files with Minimal Memory Using Excel‑Streaming‑Reader

This article explains how to prevent out‑of‑memory errors when importing huge Excel files in Java by using the open‑source excel‑streaming‑reader library, showing Maven setup, streaming code examples, memory‑saving configurations for shared strings and comments, and tips for handling extremely large workbooks.

Apache POIExcelJava

0 likes · 8 min read

Avoid OOM: Stream Massive Excel Files with Minimal Memory Using Excel‑Streaming‑Reader

Spring Full-Stack Practical Cases

May 6, 2026 · Backend Development

Convert Word to HTML with a Single Spring Boot Line for Online Preview

This article walks through building a Spring Boot 3.5.0 service that uses Apache POI and XDocReport to load a DOCX file, extract images, convert it to HTML, and expose a controller endpoint for instant online preview without external plugins.

Apache POIJavaSpring Boot

0 likes · 7 min read

Convert Word to HTML with a Single Spring Boot Line for Online Preview

Cognitive Technology Team

Dec 6, 2025 · Backend Development

How to Detect and Replace Excel Watermarks with Apache POI in Java

This guide explains how to reliably identify and remove existing watermarks from .xlsx files and then add new, precisely positioned semi‑transparent watermarks using Java's Apache POI library, complete with Maven setup, code examples, and performance tips.

Apache POIExcelFile Processing

0 likes · 10 min read

How to Detect and Replace Excel Watermarks with Apache POI in Java

Java Captain

May 15, 2025 · Backend Development

Generating Temperature Line Charts in Excel with Apache POI (Java)

This tutorial demonstrates how to add Apache POI dependencies via Maven and use Java code to create an Excel workbook containing a multi‑series temperature line chart, including custom font sizes for titles and axes, and finally export the file to disk.

Apache POIData VisualizationExcel

0 likes · 8 min read

Generating Temperature Line Charts in Excel with Apache POI (Java)

Java Architect Essentials

Dec 8, 2024 · Backend Development

Universal Java Class to Excel Export Using Reflection and Apache POI

This article demonstrates how to create a generic utility that, through Java reflection and Apache POI, can export any list of objects—regardless of their class—into a CSV/Excel file, with optional custom column names via annotations.

Apache POIExportJava

0 likes · 11 min read

Universal Java Class to Excel Export Using Reflection and Apache POI

Java Architect Essentials

Oct 31, 2024 · Backend Development

How to Read Excel, Word, PDF, and Text Files in Java

This article explains how to use Java libraries such as Apache POI, PDFBox, and EasyExcel to read Excel, DOC/DOCX, PDF, and plain text files, providing complete code examples, required Maven dependencies, and step‑by‑step usage instructions for each file type.

Apache POIFile I/OJava

0 likes · 13 min read

How to Read Excel, Word, PDF, and Text Files in Java

JD Cloud Developers

Jul 4, 2024 · Backend Development

Why Did My Excel Export Suddenly Fail? Debugging EasyPOI & Apache POI Version Conflicts

A Java developer recounts how an unexpected Excel export failure was traced to mismatched EasyPOI and Apache POI versions, the impact of Maven's -U flag, and the step‑by‑step resolution involving dependency alignment and careful version selection.

Apache POIDependency ConflictEasyPOI

0 likes · 11 min read

Why Did My Excel Export Suddenly Fail? Debugging EasyPOI & Apache POI Version Conflicts

Java Backend Technology

Dec 7, 2023 · Backend Development

Export Any Java Object to CSV/Excel with Reflection – A Universal Utility

This tutorial demonstrates how to create a universal CSV/Excel export utility in Java that can handle objects of any class by using reflection to generate headers and rows, leveraging Apache POI and Spring Boot for seamless file generation.

Apache POICSVExcel

0 likes · 10 min read

Export Any Java Object to CSV/Excel with Reflection – A Universal Utility

IT Services Circle

Nov 24, 2023 · Backend Development

Understanding and Solving Memory Overflow in Apache POI Excel Processing with EasyExcel

The article explains why Apache POI loads entire .xlsx zip files into memory causing OOM, demonstrates the issue with code examples, and shows how switching to EasyExcel's streaming read dramatically reduces memory usage while handling large Excel files in Java.

Apache POIEasyExcelExcel

0 likes · 8 min read

Understanding and Solving Memory Overflow in Apache POI Excel Processing with EasyExcel

Selected Java Interview Questions

Apr 26, 2023 · Backend Development

Implementing a Flexible Excel Export Utility with Apache POI in Java

This article explains how to build a reusable Java utility for exporting large Excel reports using Apache POI, covering header configuration, data transformation, cell formatting, multithreaded data retrieval, asynchronous handling of long‑running exports, and provides full source snippets and SQL schema examples.

Apache POIBackend DevelopmentExcel Export

0 likes · 13 min read

Implementing a Flexible Excel Export Utility with Apache POI in Java

Java Architect Essentials

Nov 24, 2022 · Backend Development

How to Efficiently Import and Export Millions of Rows with POI and EasyExcel

This article explains how to overcome the limitations of traditional Apache POI when handling massive Excel import/export tasks by comparing POI workbook types, selecting the appropriate one, and using EasyExcel together with batch database queries and JDBC transactions to process up to three million rows efficiently.

Apache POIBatch ProcessingEasyExcel

0 likes · 23 min read

How to Efficiently Import and Export Millions of Rows with POI and EasyExcel

Java Architect Essentials

Nov 14, 2022 · Big Data

Efficient Import and Export of Millions of Records Using Apache POI and EasyExcel

This article explains how to handle massive Excel import and export tasks in Java by comparing traditional POI implementations, selecting the appropriate Workbook type based on data volume, and leveraging Alibaba's EasyExcel library together with batch JDBC operations to process over three million rows with minimal memory usage and high performance.

Apache POIBig DataEasyExcel

0 likes · 22 min read

Efficient Import and Export of Millions of Records Using Apache POI and EasyExcel

Su San Talks Tech

Oct 10, 2022 · Backend Development

How a Massive Excel Import Triggered OOM in Our MQ Consumer—and the Fix

This article walks through a real‑world OOM incident in an MQ consumer caused by large Excel import/export, explains how memory dumps and Prometheus logs pinpointed the culprit, and shows how switching from XSSFWorkbook to SXSSFWorkbook and tuning the thread pool resolved the issue.

Apache POIBackend DevelopmentJava

0 likes · 9 min read

How a Massive Excel Import Triggered OOM in Our MQ Consumer—and the Fix

Su San Talks Tech

Oct 6, 2022 · Backend Development

How to Efficiently Import and Export Millions of Records with EasyExcel and POI

This article explains how to handle massive Excel import and export tasks in Java by comparing POI's HSSFWorkbook, XSSFWorkbook, and SXSSFWorkbook, selecting the right implementation, and using Alibaba's EasyExcel together with batch queries and JDBC batch inserts to process three million rows efficiently without memory overflow.

Apache POIEasyExcelJava

0 likes · 20 min read

How to Efficiently Import and Export Millions of Records with EasyExcel and POI

Selected Java Interview Questions

Sep 4, 2022 · Backend Development

Resolving OutOfMemory Errors When Using Apache POI for Large Excel Exports

This article analyzes why Apache POI runs out of memory when writing hundreds of thousands of rows to an Excel file, examines the underlying HSSFWorkbook implementation, and demonstrates how switching to the streaming SXSSFWorkbook API provides a stable, low‑memory solution for large‑scale Excel generation.

Apache POIExcelLargeData

0 likes · 6 min read

Resolving OutOfMemory Errors When Using Apache POI for Large Excel Exports

Java Architect Essentials

Jun 7, 2022 · Backend Development

Locking Cells, Setting Column Width, Row Height, Font, and Merging Cells in Excel with Apache POI

This tutorial demonstrates how to use Apache POI in Java to protect Excel sheets, unlock specific cells, adjust column widths and row heights, apply custom fonts and colors, and merge cells, providing complete code examples for each step.

Apache POICell ProtectionCell Style

0 likes · 8 min read

Locking Cells, Setting Column Width, Row Height, Font, and Merging Cells in Excel with Apache POI

Sohu Tech Products

Feb 9, 2022 · Backend Development

Java Excel Export Utility: Design, Implementation, and Usage with Apache POI

This article explains how to build a flexible Java utility for exporting large volumes of report data to Excel using Apache POI, covering customizable headers, field formatting, multithreaded data retrieval, asynchronous processing, and deployment steps.

Apache POIExcelJava

0 likes · 13 min read

Java Excel Export Utility: Design, Implementation, and Usage with Apache POI

Programmer DD

Nov 5, 2021 · Backend Development

Generate Word Docs with POI‑TL: A Minimal‑Code Template Engine for Java

This article introduces POI‑TL, a lightweight Java template engine built on Apache POI that lets developers generate Word documents with a single line of code, explains its core API, configuration options, rendering pipeline, and provides practical code examples for quick adoption.

Apache POIDocument AutomationPOI‑TL

0 likes · 9 min read

Generate Word Docs with POI‑TL: A Minimal‑Code Template Engine for Java

Top Architect

Jul 31, 2021 · Backend Development

Java Excel Import/Export Utility with Custom Annotations

This article explains how to create a reusable Java utility for Excel import and export using custom annotations, detailing the required EnableExport, EnableExportField, and ImportIndex annotations, the implementation of parsing and exporting methods with Apache POI, and providing sample code and usage examples.

Apache POIExcelImportExport

0 likes · 8 min read

Java Excel Import/Export Utility with Custom Annotations

Top Architect

Feb 5, 2021 · Backend Development

Using Apache POI to Create and Read Excel Files in Java

This article introduces Apache POI, the Java API for Microsoft Office documents, explains its core components such as Workbook, Sheet, Row, and Cell, and provides detailed code examples for creating, reading, and converting Java object lists to Excel files, including Maven dependencies and annotation usage.

Apache POIExcelJava

0 likes · 11 min read

Using Apache POI to Create and Read Excel Files in Java

Top Architect

Jan 2, 2021 · Backend Development

Optimizing Large-Scale Excel Import/Export with Apache POI to Avoid OOM and Reduce GC

This article explains how to prevent frequent full GC and out‑of‑memory errors when using Apache POI for massive Excel imports and exports by leveraging SXSSFWorkbook for XLSX, choosing appropriate processing models for XLS/XLSX, and provides performance test results and code samples.

Apache POIExcelJava

0 likes · 18 min read

Optimizing Large-Scale Excel Import/Export with Apache POI to Avoid OOM and Reduce GC

Programmer DD

Sep 22, 2020 · Backend Development

Master EasyPOI: Design Complex Excel Templates and Export Images Efficiently

This article explains how to use EasyPOI for Excel template design, covering version compatibility, Maven configuration, template creation for simple and complex reports, expression syntax, image export pitfalls, and Java code examples to render data into templates without common pitfalls.

Apache POIEasyPOIExcel

0 likes · 15 min read

Master EasyPOI: Design Complex Excel Templates and Export Images Efficiently

Java Captain

Feb 29, 2020 · Backend Development

Using Apache POI for Excel Import and Export in Java

This article demonstrates how to use Apache POI in a Maven‑based Java project to read and write both XLS and XLSX Excel files, covering library setup, core APIs, data type handling, and practical import/export implementations with Spring MVC and MyBatis.

Apache POIExcelImportExport

0 likes · 19 min read

Using Apache POI for Excel Import and Export in Java

FunTester

Aug 4, 2019 · Backend Development

Java Method to Read Excel Files and Convert Data to List of Maps

This article presents a Java utility that reads Excel files (both .xls and .xlsx) using Apache POI, extracts headers and numeric data into a nested List‑of‑Map structure, and includes error handling and type conversion details.

Apache POIData ValidationExcel

0 likes · 6 min read

Java Method to Read Excel Files and Convert Data to List of Maps

FunTester

Aug 4, 2019 · Fundamentals

Java Method for Writing Data to XLSX Files Using Apache POI

This article presents a Java method that uses Apache POI to write data into XLSX files, detailing the implementation steps, code example, and practical considerations for generating test reports with Excel in automated testing environments.

Apache POIAutomationExcel

0 likes · 3 min read

Java Method for Writing Data to XLSX Files Using Apache POI

Mafengwo Technology

Feb 18, 2019 · Backend Development

How We Built a Data‑Driven Automated Reconciliation Test Platform for Hotel Finance

This article explains how a hotel finance team tackled multi‑source, high‑volume reconciliation challenges by creating a Java‑based, data‑driven automated testing platform using Maven, TestNG, and Apache POI, improving efficiency, accuracy, and maintainability while outlining the framework architecture and future enhancements.

Apache POIBackend testingData-Driven

0 likes · 8 min read

How We Built a Data‑Driven Automated Reconciliation Test Platform for Hotel Finance

Java Captain

Jun 20, 2018 · Backend Development

Export Excel Files in Java Using Apache POI

This article demonstrates how to use Apache POI in Java to export collections of JavaBean objects to Excel files, covering generic reflection‑based implementation, styling, handling of dates, booleans, images, and integration with a servlet for download.

Apache POIExcel ExportJava

0 likes · 12 min read

Export Excel Files in Java Using Apache POI