1 files changed, 327 insertions, 0 deletions
diff --git a/src/main/java/org/openslx/filetransfer/Transfer.java b/src/main/java/org/openslx/filetransfer/Transfer.java
new file mode 100644
index 0000000..34868e3
--- /dev/null
+++ b/src/main/java/org/openslx/filetransfer/Transfer.java
@@ -0,0 +1,327 @@
+package org.openslx.filetransfer;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.net.SocketTimeoutException;
+import java.nio.charset.StandardCharsets;
+
+import javax.net.ssl.SSLContext;
+import javax.net.ssl.SSLSocket;
+import javax.net.ssl.SSLSocketFactory;
+
+import org.apache.log4j.Logger;
+
+public abstract class Transfer
+{
+	protected final SSLSocketFactory sslSocketFactory;
+	protected final SSLSocket satelliteSocket;
+	protected final DataOutputStream dataToServer;
+	protected final DataInputStream dataFromServer;
+	protected String TOKEN = null;
+	protected int[] RANGE = null;
+	protected String ERROR = null;
+
+	protected final Logger log;
+
+	protected Transfer( String ip, int port, SSLContext context, Logger log ) throws IOException
+	{
+		this.log = log;
+		// create socket.
+		sslSocketFactory = context.getSocketFactory();
+
+		satelliteSocket = (SSLSocket)sslSocketFactory.createSocket( ip, port );
+		satelliteSocket.setSoTimeout( 2000 ); // set socket timeout.
+
+		dataToServer = new DataOutputStream( satelliteSocket.getOutputStream() );
+		dataFromServer = new DataInputStream( satelliteSocket.getInputStream() );
+	}
+
+	protected Transfer( SSLSocket socket, Logger log ) throws IOException
+	{
+		this.log = log;
+		satelliteSocket = socket;
+		dataToServer = new DataOutputStream( satelliteSocket.getOutputStream() );
+		dataFromServer = new DataInputStream( satelliteSocket.getInputStream() );
+		sslSocketFactory = null;
+	}
+
+	protected boolean sendRange( int startOffset, int endOffset )
+	{
+		if ( RANGE != null ) {
+			log.warn( "Range already set!" );
+			return false;
+		}
+		try {
+			sendKeyValuePair( "RANGE", startOffset + ":" + endOffset );
+		} catch ( SocketTimeoutException ste ) {
+			ste.printStackTrace();
+			log.info( "Socket timeout occured ... close connection." );
+			this.close();
+		} catch ( IOException e ) {
+			e.printStackTrace();
+			readMetaData();
+			if ( ERROR != null ) {
+				if ( ERROR == "timeout" ) {
+					log.info( "Socket timeout occured ... close connection." );
+					this.close();
+				}
+			}
+			log.info( "Sending RANGE in Uploader failed..." );
+			return false;
+		}
+		return true;
+	}
+
+	/***********************************************************************/
+	/**
+	 * Method for sending token for identification from satellite to master.
+	 * 
+	 * @param token The token to send
+	 */
+	public boolean sendToken( String token )
+	{
+		if ( TOKEN != null ) {
+			log.warn( "Trying to send token while a token is already set! Ignoring..." );
+			return false;
+		}
+		TOKEN = token;
+		try {
+			sendKeyValuePair( "TOKEN", TOKEN );
+		} catch ( SocketTimeoutException ste ) {
+			ste.printStackTrace();
+			log.info( "Socket timeout occured ... close connection." );
+			this.close();
+		} catch ( IOException e ) {
+			e.printStackTrace();
+			readMetaData();
+			if ( ERROR != null ) {
+				if ( ERROR == "timeout" ) {
+					log.info( "Socket timeout occured ... close connection." );
+					this.close();
+				}
+			}
+			log.info( "Sending TOKEN in Downloader failed..." );
+			return false;
+		}
+		return true;
+	}
+
+	/***********************************************************************/
+	/**
+	 * Method for reading incoming token for identification.
+	 * 
+	 */
+	public String getToken()
+	{
+		return TOKEN;
+	}
+
+	private boolean parseRange( String range )
+	{
+		if ( range == null )
+			return true;
+		if ( RANGE != null ) {
+			log.warn( "Warning: RANGE already set when trying to parse from " + range );
+			return false;
+		}
+		String parts[] = range.split( ":", 2 );
+		int ret[] = new int[ 2 ];
+		try {
+			ret[0] = Integer.parseInt( parts[0] );
+			ret[1] = Integer.parseInt( parts[1] );
+		} catch ( Throwable t ) {
+			log.warn( "Not parsable range: '" + range + "'" );
+			return false;
+		}
+		if ( ret[1] <= ret[0] ) {
+			log.warn( "Invalid range. Start >= end" );
+			return false;
+		}
+		RANGE = ret;
+		return true;
+	}
+
+	/***********************************************************************/
+	/**
+	 * Getter for beginning of RANGE.
+	 * 
+	 * @return
+	 */
+	public int getStartOfRange()
+	{
+		if ( RANGE != null ) {
+			return RANGE[0];
+		}
+		return -1;
+	}
+
+	/***********************************************************************/
+	/**
+	 * Getter for end of RANGE.
+	 * 
+	 * @return
+	 */
+	public int getEndOfRange()
+	{
+		if ( RANGE != null ) {
+			return RANGE[1];
+		}
+		return -1;
+	}
+
+	/***********************************************************************/
+	/**
+	 * Method for returning difference of current Range.
+	 * 
+	 * @return
+	 */
+	public int getDiffOfRange()
+	{
+		int diff = Math.abs( getEndOfRange() - getStartOfRange() );
+		return diff;
+	}
+
+	/***********************************************************************/
+	/**
+	 * Method for reading MetaData, like TOKEN and FileRange.
+	 * Split incoming bytes after first '=' and store value to specific
+	 * variable.
+	 * 
+	 * @return true on success, false if reading failed
+	 */
+	public boolean readMetaData()
+	{
+		try {
+			while ( true ) {
+				byte[] incoming = new byte[ 255 ];
+
+				// First get length.
+				int retLengthByte;
+				retLengthByte = dataFromServer.read( incoming, 0, 1 );
+				if ( retLengthByte != 1 ) {
+					this.close();
+					return false;
+				}
+
+				int length = incoming[0] & 0xFF;
+				log.debug( "length (downloader): " + length );
+
+				if ( length == 0 )
+					break;
+
+				/*
+				 * Read the next available bytes and split by '=' for
+				 * getting TOKEN or RANGE.
+				 */
+				int hasRead = 0;
+				while ( hasRead < length ) {
+					int ret = dataFromServer.read( incoming, hasRead, length - hasRead );
+					if ( ret == -1 ) {
+						log.warn( "Error occured while reading Metadata." );
+						this.close();
+						return false;
+					}
+					hasRead += ret;
+				}
+
+				String data = new String( incoming, 0, length, StandardCharsets.UTF_8 );
+
+				String[] splitted = data.split( "=", 2 );
+				if ( splitted.length != 2 ) {
+					log.warn( "Invalid key value pair received (" + data + ")" );
+					continue;
+				}
+				if ( splitted[0].equals( "TOKEN" ) ) {
+					if ( TOKEN != null ) {
+						log.warn( "Received a token when a token is already set!" );
+						this.close();
+						return false;
+					}
+					TOKEN = splitted[1];
+					log.debug( "TOKEN: " + TOKEN );
+				}
+				else if ( splitted[0].equals( "RANGE" ) ) {
+					if ( !parseRange( splitted[1] ) ) {
+						this.close();
+						return false;
+					}
+					log.debug( "RANGE: '" + splitted[1] + "'" );
+				}
+				else if ( splitted[0].equals( "ERROR" ) ) {
+					ERROR = splitted[1];
+					log.debug( "ERROR: " + ERROR );
+				}
+			}
+		} catch ( SocketTimeoutException ste ) {
+			ste.printStackTrace();
+			sendErrorCode( "timeout" );
+			log.info( "Socket Timeout occured in Downloader." );
+			this.close();
+			return false;
+		} catch ( Exception e ) {
+			e.printStackTrace();
+			this.close();
+			return false;
+		}
+		return true;
+	}
+
+	private void sendKeyValuePair( String key, String value ) throws IOException
+	{
+		byte[] data = ( key + "=" + value ).getBytes( StandardCharsets.UTF_8 );
+		dataToServer.writeByte( data.length );
+		dataToServer.write( data );
+	}
+
+	/***********************************************************************/
+	/**
+	 * Method for sending error Code to server. For example in case of wrong
+	 * token, send code for wrong token.
+	 * 
+	 */
+	public Boolean sendErrorCode( String errString )
+	{
+		try {
+			sendKeyValuePair( "ERROR", errString );
+		} catch ( IOException e ) {
+			e.printStackTrace();
+			this.close();
+			return false;
+		}
+		return true;
+	}
+
+	/***********************************************************************/
+	/**
+	 * Method for closing connection, if download has finished.
+	 * 
+	 */
+	public void close()
+	{
+		try {
+			if ( satelliteSocket != null ) {
+				this.satelliteSocket.close();
+			}
+			if ( dataFromServer != null )
+				dataFromServer.close();
+			if ( dataToServer != null )
+				dataToServer.close();
+		} catch ( IOException e ) {
+			e.printStackTrace();
+		}
+	}
+
+	/**
+	 * Returns whether this transfer/connection is considered valid or usable,
+	 * which means the socket is still properly connected to the remote peer.
+	 * 
+	 * @return true or false
+	 */
+	public boolean isValid()
+	{
+		return satelliteSocket.isConnected() && !satelliteSocket.isClosed()
+				&& !satelliteSocket.isInputShutdown() && !satelliteSocket.isOutputShutdown();
+	}
+
+}