cdefgah / bencoder4j

Bit-torrent encoding and decoding implementation for Java programming language.

Bencode Serializer and Deserializer

Bit-torrent encoding and decoding implementation for the Java programming language.

Simple use case

This project is available as a Maven dependency:

<dependency>
    <groupId>com.github.cdefgah</groupId>
    <artifactId>bencoder4j</artifactId>
    <version>1.1.0</version>
</dependency>

Below, you can see a piece of code that writes a set of arbitrary objects to the file.ben, located in my home Downloads folder.

Bear in mind that provided examples fit my OS (Ubuntu Linux) and environment (path with my user name). Chances are that these parameters slightly differ in your case, so be sure to modify the filePath variable accordingly.

package example;

import com.github.cdefgah.bencoder4j.CircularReferenceException;
import com.github.cdefgah.bencoder4j.model.BencodedByteSequence;
import com.github.cdefgah.bencoder4j.model.BencodedDictionary;
import com.github.cdefgah.bencoder4j.model.BencodedInteger;
import com.github.cdefgah.bencoder4j.model.BencodedList;

import java.io.FileOutputStream;
import java.io.IOException;

public class WriterApp {

    public static void main(String[] args) throws IOException, CircularReferenceException {

        BencodedInteger bencodedInteger = new BencodedInteger(1234567890);
        BencodedByteSequence bencodedByteSequence = new BencodedByteSequence("Hi :)");

        BencodedList bencodedList = new BencodedList();
        BencodedInteger intListElement = new BencodedInteger(1);
        BencodedByteSequence bbsListElement = new BencodedByteSequence("abc");

        bencodedList.add(intListElement);
        bencodedList.add(bbsListElement);

        BencodedDictionary bencodedDictionary = new BencodedDictionary();

        BencodedByteSequence dictKey1 = new BencodedByteSequence("111");
        BencodedByteSequence dictKey2 = new BencodedByteSequence("222");

        BencodedInteger intDictElement = new BencodedInteger(2);
        BencodedByteSequence bbsDictElement = new BencodedByteSequence("xyz");

        bencodedDictionary.put(dictKey1, intDictElement);
        bencodedDictionary.put(dictKey2, bbsDictElement);


        String filePath = "/home/rafael/Downloads/file.ben";
        try (FileOutputStream fos = new FileOutputStream(filePath)) {

            bencodedInteger.writeObject(fos);
            bencodedByteSequence.writeObject(fos);
            bencodedList.writeObject(fos);
            bencodedDictionary.writeObject(fos);

        }
    }
}

Now, as we have the composed file.benin the Downloads folder, we can use the following code to read its contents.

package example;

import com.github.cdefgah.bencoder4j.BencodeFormatException;
import com.github.cdefgah.bencoder4j.io.BencodeStreamIterator;
import com.github.cdefgah.bencoder4j.model.BencodedObject;

import java.io.FileInputStream;
import java.io.IOException;

public class ReaderApp {
    public static void main(String[] args) throws IOException, BencodeFormatException {

        String filePath = "/home/rafael/Downloads/file.ben";
        try(FileInputStream fis = new FileInputStream(filePath)) {
            BencodeStreamIterator bis = new BencodeStreamIterator(fis);

            while (bis.hasNext()) {
                BencodedObject bencodedObject = bis.next();
                System.out.println(bencodedObject);
            }
        }
    }
}

Use cases given above are the most basic, simple examples. For more please refer to the tests for the project.

Documentation

API Documentation

Changelog

Licensing

MIT License