ZipHelper Tutorial

This tutorial provides an overview of the ZipHelper class, which is part of the lightweight-component/aj-util library. The ZipHelper class provides utility methods for ZIP compression and decompression operations.

Introduction

The ZipHelper class contains static methods for working with ZIP files, including compression, decompression, and file type detection.

Main Features

• ZIP file decompression with directory handling
• File and directory compression (with STORED or DEFLATED options)
• Recursive directory compression
• ZIP file detection (magic number check)
• CRC32 checksum calculation
• Automatic directory creation

Methods

1. Decompression

1. unzip(String save, String zipFile) - Decompress ZIP file to target directory

2. Compression

1. zipFile(File[] fileContent, String saveZip, boolean useStore) - Compress files to ZIP
2. zipDirectory(String sourceDir, String saveZip, boolean useStore) - Compress directory to ZIP

3. Utility Methods

1. initFolder(File file) - Ensure parent directories exist for a file
2. initFolder(String file) - String version of initFolder
3. isZipFile(String filePath) - Check if file is a valid ZIP file
4. getFileCRCCode(File file) - Calculate CRC32 checksum for a file

Usage Examples

Decompression

ZipHelper.unzip("C:/extracted", "C:/archive.zip");

File Compression

File[] files = {new File("file1.txt"), new File("file2.txt")};
ZipHelper.zipFile(files, "archive.zip", false); // Use DEFLATED compression

Directory Compression

ZipHelper.zipDirectory("C:/data", "backup.zip", true); // Use STORED (no compression)

ZIP File Detection

boolean isZip = ZipHelper.isZipFile("unknown.zip");

Directory Creation

ZipHelper.initFolder("C:/new/path/file.txt"); // Creates C:/new/path if needed

Compression Methods

The class supports two compression methods:

1. DEFLATED (default) - Standard ZIP compression
2. STORED - No compression, files are stored as-is

Error Handling

The methods handle common IO errors and log warnings when issues occur during compression/decompression.

Conclusion

The ZipHelper class provides comprehensive utility methods for working with ZIP files, making compression and decompression operations more convenient in Java applications.