P2P File Sharing Guide

How To Use

Basic Program Compilation

1. Navigate to the src folder and run the following command:

   javac -cp . ./Main/Main.java ./discovery/.java ./discovery/messages/.java ./p2p/.java ./testing/.java

2. Start the central server:

   java -cp . Main.Main central <!CentralServerIP!> <!CentralServerPort!>

3. Start a peer:

   java -cp . Main.Main peer <!PeerIP!> <!PeerPort!> <!CentralServerIP!> <!CentralServerPort!>

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How To Upload a File

1. Run the peer command as shown above.
2. Use the following command to upload a file:

   upload <!FILEPATHINOS!>

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How To Download a File

1. Run the peer command as shown above.
2. Use the following command to download a file:

   download

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How to Test

1. In the test directory, add a file containing the paths of all the files to be tested.
2. Run the following command to start testing:

   java -cp . Main.Main testing <!test Name!>

   Currently, the test will use a three-node setup to perform the testing.

Project Structure

• src/

  • Main/
    • Main.java: Entry point. Parses CLI, adapts peer/central roles, and user commands.
  • discovery/
    • CentralRegistry.java: Central server logic for file and peer discovery.
    • Handshake.java: Session setup and request/response coordination between peers and central.
    • FileData.java: Metadata for files (name, size, hash) used across discovery and transfer.
    • Node.java: Represents a peer (IP, port, identity).
    • messages/: Serializable message types exchanged over the network
      • CentralRegistryRequest.java, CentralRegistryResponse.java
      • FileRequest.java, FileResponse.java
      • TransferRequest.java, TransferResponse.java
      • BroadcastBeacon.java: Beacon used for UDP broadcast transfers.
  • p2p/
    • ConnectionHandlerSequential.java: Encrypted sequential TCP file send/receive.
    • ConnectionHandlerParallel.java: Simpler TCP send/receive variant.
    • FileReciever.java: High-level download flow (queries registry, selects peer, saves to downloads dir).
    • ObjectTransfer.java: Object serialization over TCP and UDP broadcast helpers.
    • BroadCastTransfer.java: File broadcasting and reception over UDP using beacons.
  • testing/
    • FileTesting.java: Test harness that spins up central, sender, receiver from a list of file paths.
  • utils/
    • UserExperience.java: Console progress bar utilities for transfers.
    • Config.java: Centralized config loader; provides getTestDir() and getDownloadsDir().
  • test/
    • Test input lists (e.g., unit.txt, big.txt, encryption.txt) consumed in testing mode.
  • downloads/
    • Default downloads target directory (configurable via config.properties).

• bin/

  • Compiled .class files organized mirroring src/ packages.

• config.properties

  • Repository-level configuration for directories:
    • test.dir: Directory containing test list files (default ./src/test).
    • downloads.dir: Directory where downloads are saved (default ./src/downloads).