This is an I2P port of snark [http://klomp.org/snark], a GPL'ed bittorrent client

The build in tracker has been removed for simplicity.

Example usage:
  java -jar lib/i2psnark.jar myFile.torrent

or, a more verbose setting:
  java -jar lib/i2psnark.jar --eepproxy 127.0.0.1 4444 \
       --i2cp 127.0.0.1 7654 "inbound.length=2 outbound.length=2" \
       --debug 6 myFile.torrent

apps/i2psnark/java/src/org/klomp/snark/I2PSnarkUtil.java

@@ -0,0 +1,165 @@
+package org.klomp.snark;
+
+import net.i2p.I2PAppContext;
+import net.i2p.I2PException;
+import net.i2p.util.EepGet;
+import net.i2p.data.Base64;
+import net.i2p.data.DataFormatException;
+import net.i2p.data.Destination;
+import net.i2p.client.streaming.I2PServerSocket;
+import net.i2p.client.streaming.I2PSocket;
+import net.i2p.client.streaming.I2PSocketManager;
+import net.i2p.client.streaming.I2PSocketManagerFactory;
+import net.i2p.util.Log;
+
+import java.io.*;
+import java.util.Properties;
+
+/**
+ * I2P specific helpers for I2PSnark
+ */
+public class I2PSnarkUtil {
+    private I2PAppContext _context;
+    private Log _log;
+    private static I2PSnarkUtil _instance = new I2PSnarkUtil();
+    public static I2PSnarkUtil instance() { return _instance; }
+    
+    private boolean _shouldProxy;
+    private String _proxyHost;
+    private int _proxyPort;
+    private String _i2cpHost;
+    private int _i2cpPort;
+    private Properties _opts;
+    private I2PSocketManager _manager;
+    
+    private I2PSnarkUtil() {
+        _context = I2PAppContext.getGlobalContext();
+        _log = _context.logManager().getLog(Snark.class);
+        setProxy("127.0.0.1", 4444);
+        setI2CPConfig("127.0.0.1", 7654, null);
+    }
+    
+    /**
+     * Specify what HTTP proxy tracker requests should go through (specify a null
+     * host for no proxying)
+     *
+     */
+    public void setProxy(String host, int port) {
+        if ( (host != null) && (port > 0) ) {
+            _shouldProxy = true;
+            _proxyHost = host;
+            _proxyPort = port;
+        } else {
+            _shouldProxy = false;
+            _proxyHost = null;
+            _proxyPort = -1;
+        }
+    }
+    
+    public void setI2CPConfig(String i2cpHost, int i2cpPort, Properties opts) {
+        _i2cpHost = i2cpHost;
+        _i2cpPort = i2cpPort;
+        if (opts != null)
+            _opts = opts;
+    }
+    
+    /**
+     * Connect to the router, if we aren't already
+     */
+    boolean connect() {
+        if (_manager == null) {
+            _manager = I2PSocketManagerFactory.createManager(_i2cpHost, _i2cpPort, _opts);
+        }
+        return (_manager != null);
+    }
+    
+    /** connect to the given destination */
+    I2PSocket connect(PeerID peer) throws IOException {
+        try {
+            return _manager.connect(peer.getAddress());
+        } catch (I2PException ie) {
+            throw new IOException("Unable to reach the peer " + peer + ": " + ie.getMessage());
+        }
+    }
+    
+    /**
+     * fetch the given URL, returning the file it is stored in, or null on error
+     */
+    File get(String url) {
+        File out = null;
+        try {
+            out = File.createTempFile("i2psnark", "url");
+        } catch (IOException ioe) {
+            ioe.printStackTrace();
+            return null;
+        }
+        EepGet get = new EepGet(_context, _shouldProxy, _proxyHost, _proxyPort, 1, out.getAbsolutePath(), url);
+        if (get.fetch()) {
+            return out;
+        } else {
+            out.delete();
+            return null;
+        }
+    }
+    
+    I2PServerSocket getServerSocket() { 
+        return _manager.getServerSocket();
+    }
+    
+    String getOurIPString() {
+        return _manager.getSession().getMyDestination().toBase64();
+    }
+    Destination getDestination(String ip) {
+        if (ip == null) return null;
+        if (ip.endsWith(".i2p")) {
+            Destination dest = _context.namingService().lookup(ip);
+            if (dest != null) {
+                return dest;
+            } else {
+                try {
+                    return new Destination(ip.substring(0, ip.length()-4)); // sans .i2p
+                } catch (DataFormatException dfe) {
+                    return null;
+                }
+            }
+        } else {
+            try {
+                return new Destination(ip);
+            } catch (DataFormatException dfe) {
+                return null;
+            }
+        }
+    }
+
+    /**
+     * Given http://blah.i2p/foo/announce turn it into http://i2p/blah/foo/announce
+     */
+    String rewriteAnnounce(String origAnnounce) {
+        int destStart = "http://".length();
+        int destEnd = origAnnounce.indexOf(".i2p");
+        int pathStart = origAnnounce.indexOf('/', destEnd);
+        return "http://i2p/" + origAnnounce.substring(destStart, destEnd) + origAnnounce.substring(pathStart);
+    }
+    
+    /** hook between snark's logger and an i2p log */
+    void debug(String msg, int snarkDebugLevel, Throwable t) {
+        switch (snarkDebugLevel) {
+            case 0:
+            case 1:
+                _log.error(msg, t);
+                break;
+            case 2:
+                _log.warn(msg, t);
+                break;
+            case 3:
+            case 4:
+                _log.info(msg, t);
+                break;
+            case 5:
+            case 6:
+            default:
+                _log.debug(msg, t);
+                break;
+        }
+    }
+}