7z Compression of files using Apache Commons Compress API

Here is a demo program to demonstrate archiving of files to 7z format using Apache Commons Compress API

List of Jars required:

• xz-1.4.jar
• commons-compress-1.8.jar
  
  

  package demo.sevenzcompression.examples;
  
  import java.io.*;
  import java.text.SimpleDateFormat;
  import java.util.ArrayList;
  import java.util.Date;
  
  import org.apache.commons.compress.archivers.sevenz.*;
  
  public class SevenZCompressionDemo {
  
  	public static void main(String args[]) {
  
  		// set the files to be archived
  		File file1 = new File("Demo1.csv");
  		File file2 = new File("Demo2.csv");
  		File file3 = new File("Demo3.csv");
  		File file4 = new File("Demo4.csv");
  
  		// add files to an array list
  		ArrayList<File> filesToArchive = new ArrayList<File>();
  		filesToArchive.add(file1);
  		filesToArchive.add(file2);
  		filesToArchive.add(file3);
  		filesToArchive.add(file4);
  
  		// get formatted file name with system date (ex: Archive_20140709.7z)
  		String sevenZarchiveFileName = getFormattedFileName();
  		File sevenZFile = new File(sevenZarchiveFileName);
  		SevenZOutputFile sevenZOutput = null;
  
  		System.out.println("Attempting to create " + sevenZarchiveFileName
  				+ ".......");
  
  		try {
  			sevenZOutput = new SevenZOutputFile(sevenZFile);
  		} catch (IOException e1) {
  
  			System.out.println(e1.getMessage());
  			System.exit(0);
  		}
  		for (int i = 0; i < filesToArchive.size(); i++) {
  			try {
  
  				SevenZArchiveEntry entry = sevenZOutput.createArchiveEntry(
  						filesToArchive.get(i), filesToArchive.get(i).getName());
  				sevenZOutput.putArchiveEntry(entry);
  				FileInputStream in = new FileInputStream(filesToArchive.get(i));
  				byte[] b = new byte[1024];
  				int count = 0;
  				while ((count = in.read(b)) > 0) {
  					sevenZOutput.write(b, 0, count);
  				}
  				sevenZOutput.closeArchiveEntry();
  				in.close();
  
  			} catch (IOException e) {
  
  				System.out.println(e.getMessage());
  				System.exit(0);
  			}
  		}
  		try {
  			sevenZOutput.close();
  			System.out.println("Archive " + sevenZarchiveFileName
  					+ " created successfully.......");
  
  		} catch (IOException e) {
  
  			System.out.println(e.getMessage());
  
  		}
  
  	}
  
  	private static String getFormattedFileName() {
  
  		long millis = System.currentTimeMillis();
  		Date date = new Date(millis);
  		SimpleDateFormat df = new SimpleDateFormat("yyyyMMdd");
  		String filename = "Archive_" + df.format(date) + ".7z";
  		return filename;
  	}
  
  }