View & Export MPP Files via Open Source Java Library

Getting Started with mpp-viewer

mpp-viewer is a standalone Java application available on GitHub. You can download the latest release from the mpp-viewer GitHub repository, or build it from source using Maven. The project includes pre-built JAR files for immediate use. Simply download the JAR, ensure Java 8 or higher is installed, and run it with java -jar mpp-viewer.jar. No installation or configuration is required — making it ideal for quick project plan reviews on Windows, macOS, or Linux. Its lightweight footprint ensures fast startup and smooth performance even with large MPP files.

java -jar mpp-viewer.jar

View MPP Files with Full Task Hierarchy

mpp-viewer displays Microsoft Project tasks in a structured, hierarchical tree view, preserving the original WBS (Work Breakdown Structure) and parent-child relationships. Each task shows key details such as name, start date, end date, duration, % complete, and predecessor links. Resources assigned to tasks are also listed, giving users a comprehensive view of workload distribution. The interface mimics Microsoft Project’s familiar layout, reducing the learning curve for existing users. This makes it especially useful for project managers who need to quickly review project timelines and dependencies without opening the full Microsoft Project application.

// mpp-viewer is launched via GUI; no code needed for basic viewing
// However, internally it uses MPXJ library to parse MPP files:
// net.sf.mpxj.reader.MPPReader reader = new MPPReader();
// ProjectFile project = reader.read(new File("project.mpp"));

Highlight Completed and Delayed Tasks

mpp-viewer automatically highlights tasks based on their status — completed tasks appear in green, while delayed (overdue) tasks are shown in red. This visual cue helps project managers quickly identify at-risk items and track progress at a glance. The highlighting logic uses the task’s % complete and actual finish date compared to the baseline schedule. Users can customize or toggle highlighting via the UI settings. This real-time status visualization enhances decision-making and status reporting, especially during project reviews or stakeholder meetings where quick insights are critical.

// Highlighting is handled internally by the UI renderer:
// if (task.getActualFinish() != null && task.getActualFinish().before(today)) {
//     style = Style.COMPLETED;
// } else if (task.getFinish().before(today) && task.getPercentComplete() < 100) {
//     style = Style.DELAYED;
// }
// No user code required — highlighting is automatic.

Export MPP Data to Excel

mpp-viewer includes a built-in export feature that converts MPP project data into Excel (XLS/XLSX) format. This is invaluable for sharing project timelines with stakeholders who don’t have access to Microsoft Project. The export preserves key fields like task name, dates, duration, resources, and predecessors in a structured spreadsheet layout. Users can select specific tasks or export the entire project. The resulting Excel file is ready for further analysis, reporting, or integration into other tools like Power BI or Excel PivotTables — making mpp-viewer a powerful bridge between enterprise project planning and business intelligence workflows.

// Export is triggered via UI menu: File → Export → Excel
// Internally, Apache POI is used:
// Workbook workbook = new XSSFWorkbook();
// Sheet sheet = workbook.createSheet("Tasks");
// // Write header and task rows...
// try (FileOutputStream fos = new FileOutputStream("export.xlsx")) {
//     workbook.write(fos);
// }

Search and Copy Task Information

mpp-viewer provides a fast search bar to locate tasks by name, ID, or resource — ideal for large projects with hundreds of tasks. Results are highlighted in the task list, and users can click to jump directly to the task. Additionally, you can select and copy any task detail (e.g., dates, predecessors, notes) to the clipboard for use in emails, reports, or documentation. This eliminates manual retyping and reduces errors. The combination of search and copy functionality significantly improves productivity during project audits, status updates, or cross-team coordination.

// Search is handled via UI input field:
// List results = project.getTasks().stream()
//     .filter(t -> t.getName().toLowerCase().contains(query))
//     .collect(Collectors.toList());
// Copy uses standard Java Toolkit:
// Toolkit.getDefaultToolkit().getSystemClipboard()
//     .setContents(new StringSelection(task.getName()), null);