First steps

Download and extraction

The most simple way to get 7-Zip-JBinding to work is to download a pre-compiled binary package for your operating system (download link). All provided packages are Zip-compressed and you will need an extraction utility to expand them. For windows users is securing a copy of 7-Zip is highly recommended. Linux and Mac OS X users may use the corresponding command line tool p7Zip.

Run an example

To use the 7-Zip-JBinding library you will need two JAR-files from lib folder of the distribution in your classpath:

sevenzip-jbinding.jar - java part of 7-Zip-JBinding. (JavaDoc)
sevenzip-jbinding-‹OS›.jar - native libraries for the target operating system ‹OS›

Here is a simple test program that can be used for checking all 7-Zip-JBinding requirements:

import net.sf.sevenzipjbinding.SevenZip;
import net.sf.sevenzipjbinding.SevenZipNativeInitializationException;

public class SevenZipJBindingInitCheck {
    public static void main(String[] args) {
        try {
            SevenZip.initSevenZipFromPlatformJAR();
            System.out.println("7-Zip-JBinding library was initialized");
        } catch (SevenZipNativeInitializationException e) {
            e.printStackTrace();
        }
    }
}

download java code

To run this program correctly you will need to add two 7-Zip-JBinding JAR-files to the classpath. On Linux it could be done as following:

$ java -cp ‹path-to-lib›/sevenzip-jbinding.jar:\ 
  ‹path-to-lib›/sevenzipjbinding-Linux-i686.jar:. \ 
  SevenZipJBindingInitCheck

Windows users can do the same with (written in a single line)

C:\Test> java -cp ‹path-to-lib›\sevenzip-jbinding.jar; 
  ‹path-to-lib›\sevenzipjbinding-Windows-x86.jar;.
  SevenZipJBindingInitCheck

If the message

7-Zip-JBinding library was initialized

shows up than 7-Zip-JBinding is working properly and is ready for use.

Opening an archive

Before you can do any operation on an archive file, you have to open it. In order to do this you will need to call one of the corresponding static methods SevenZip.openInArchive(...). The only mandatory parameter is "inStream" - an instance of the IInStream interface.

In many cases the task is to open an archive file from the file system. 7-Zip-JBinding has a standard implementation of IInStream for this purpose: RandomAccessFileInStream. As the name says, this takes an instance of RandomAccessFile and turns it into an instance of IInStream.

Here is a simple example of how to open an archive from the file system:

public void openArchive(String archiveFilename) 
        throws SevenZipException, FileNotFoundException {

    randomAccessFile = new RandomAccessFile(archiveFilename, "r");

    inArchive = SevenZip.openInArchive(null, // Choose format automatically
            new RandomAccessFileInStream(randomAccessFile));
}

download java code

The opened archive can now be used for exploring and extraction operations. The last method called on archive should always be ISevenZipInArchive.close(). This closes the archive and frees system resources. The last, but not least, step is to close the random access file 'randomAccessFile' using close() method of the RandomAccessFile class.

Here is a complete program to print count of items in the archive:

import java.io.IOException;
import java.io.RandomAccessFile;

import net.sf.sevenzipjbinding.ISevenZipInArchive;
import net.sf.sevenzipjbinding.SevenZip;
import net.sf.sevenzipjbinding.SevenZipException;
import net.sf.sevenzipjbinding.impl.RandomAccessFileInStream;

public class PrintCountOfItems {
    public static void main(String[] args) {
        if (args.length == 0) {
            System.out.println("Usage: java PrintCountOfItems <archive-name>");
            return;
        }
        String archiveFilename = args[0];

        RandomAccessFile randomAccessFile = null;
        ISevenZipInArchive inArchive = null;
        try {
            randomAccessFile = new RandomAccessFile(archiveFilename, "r");
            inArchive = SevenZip.openInArchive(null, // autodetect archive type
                    new RandomAccessFileInStream(randomAccessFile));

            System.out.println("Count of items in archive: " 
                    + inArchive.getNumberOfItems());

        } catch (Exception e) {
            System.err.println("Error occurs: " + e);
            System.exit(1);
        } finally {
            if (inArchive != null) {
                try {
                    inArchive.close();
                } catch (SevenZipException e) {
                    System.err.println("Error closing archive: " + e);
                }
            }
            if (randomAccessFile != null) {
                try {
                    randomAccessFile.close();
                } catch (IOException e) {
                    System.err.println("Error closing file: " + e);
                }
            }
        }
    }
}

download java code

If you run this program with

C:\Test> java -cp ‹path-to-lib›\sevenzip-jbinding.jar; 
  ‹path-to-lib›\sevenzipjbinding-Windows-x86.jar;.
  PrintCountOfItems my-test-archive.zip

you should get something like this:

Count of items in archive: 4

Continue with Code snippets to get more examples.