Blockchain in java done (comments pending)

Author: rampatra

src/main/java/com/rampatra/blockchain/Blockchain.java

@@ -135,4 +135,12 @@ private static String bytesToHex(byte[] hash) {
         }
         return hexString.toString();
     }
+
+    @Override
+    public String toString() {
+        final StringBuilder sb = new StringBuilder("Blockchain{");
+        sb.append("blocks=").append(blocks);
+        sb.append('}');
+        return sb.toString();
+    }
 }

src/main/java/com/rampatra/blockchain/P2P.java

@@ -18,6 +18,12 @@ public static Peer addPeer(Blockchain blockchain) {
         peers.add(peer);
         return peer;
     }
+    
+    public static void removePeer(int index) {
+        Peer peer = peers.get(index);
+        peer.stopServer();
+        peers.remove(index);
+    }
 
     public static void removePeer(Peer peer) {
         Iterator<Peer> iterator = peers.iterator();
@@ -29,8 +35,33 @@ public static void removePeer(Peer peer) {
             }
         }
     }
+    
+    public static void removeAllPeers() {
+        Iterator<Peer> iterator = peers.iterator();
+        while (iterator.hasNext()) {
+            Peer peer = iterator.next();
+            peer.stopServer();
+            iterator.remove();
+        }
+    }
+    
+    public static Peer getPeer(int index) {
+        return peers.get(index);
+    }
 
     public static List<Peer> getPeers() {
         return peers;
     }
+    
+    public static void showPeers() {
+        for (int i = 0; i < peers.size(); i++) {
+            System.out.println("Peer " + (i + 1) + ": " + peers.get(i).getPort());
+        }
+    }
+
+    public static void showPeersWithBlockchain() {
+        for (int i = 0; i < peers.size(); i++) {
+            System.out.println("Peer " + (i + 1) + ": " + peers.get(i).getBlockchain());
+        }
+    }
 }

src/main/java/com/rampatra/blockchain/Peer.java

@@ -5,6 +5,7 @@
 import java.net.Socket;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Scanner;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.stream.Collectors;
@@ -39,7 +40,7 @@ private void startServer() {
             throw new RuntimeException(e);
         }
     }
-    
+
     public void stopServer() {
         try {
             if (!server.isClosed()) {
@@ -89,29 +90,76 @@ public void setBlockchain(Blockchain blockchain) {
         this.blockchain = blockchain;
     }
 
+    public int getPort() {
+        return port;
+    }
+
     @Override
     public String toString() {
         final StringBuilder sb = new StringBuilder("Peer{");
-        sb.append("port=").append(port);
+        sb.append("blockchain=").append(blockchain);
+        sb.append(", port=").append(port);
         sb.append('}');
         return sb.toString();
     }
 
     public static void main(String[] args) {
-        Blockchain blockchain = new Blockchain(new ArrayList<>(), 3);
-        Peer peer1 = P2P.addPeer(blockchain);
-        System.out.println("Peers:" + P2P.getPeers());
-        peer1.mine("1st block by p1");
-        System.out.println("Blockchain with p1: " + peer1.getBlockchain().getBlocks());
-        Peer peer2 = P2P.addPeer(blockchain);
-        System.out.println("Peers: " + P2P.getPeers());
-        System.out.println("Blockchain with p1: " + peer1.getBlockchain().getBlocks());
-        System.out.println("Blockchain with p2: " + peer2.getBlockchain().getBlocks());
-        peer2.mine("2nd block by p2");
-        System.out.println("Blockchain with p1: " + peer1.getBlockchain().getBlocks());
-        System.out.println("Blockchain with p2: " + peer2.getBlockchain().getBlocks());
-        peer1.mine("3rd block by p1");
-        System.out.println("Blockchain with p1: " + peer1.getBlockchain().getBlocks());
-        System.out.println("Blockchain with p2: " + peer2.getBlockchain().getBlocks());
+        try {
+            int menuChoice;
+            int peerIndex;
+            String data;
+            Scanner s = new Scanner(System.in);
+            Blockchain blockchain = new Blockchain(new ArrayList<>(), 3);
+
+            while (true) {
+
+                System.out.println("\n======= Welcome to Blockchain in Java =======");
+                System.out.println("1. Add Peer");
+                System.out.println("2. Mine data in peer");
+                System.out.println("3. Remove peer");
+                System.out.println("4. Show peers");
+                System.out.println("5. Exit");
+
+                menuChoice = s.nextInt();
+
+                switch (menuChoice) {
+                    case 1:
+                        P2P.addPeer(blockchain);
+                        System.out.println("New peer added!");
+                        P2P.showPeersWithBlockchain();
+                        break;
+                    case 2:
+                        System.out.println("Choose peer: (ex. 1, 2, etc.)");
+                        P2P.showPeers();
+                        peerIndex = s.nextInt();
+                        Peer p = P2P.getPeer(peerIndex - 1);
+                        System.out.println("Enter data: ");
+                        data = s.next();
+                        p.mine(data);
+                        System.out.println("Data mined!");
+                        P2P.showPeersWithBlockchain();
+                        break;
+                    case 3:
+                        System.out.println("Choose peer: (ex. 1, 2, etc.)");
+                        P2P.showPeers();
+                        peerIndex = s.nextInt();
+                        P2P.removePeer(peerIndex - 1);
+                        System.out.println("Peer " + peerIndex + " removed!");
+                        P2P.showPeersWithBlockchain();
+                        break;
+                    case 4:
+                        P2P.showPeersWithBlockchain();
+                        break;
+                    case 5:
+                        P2P.removeAllPeers();
+                        System.out.println("Bye, see you soon!");
+                        System.exit(0);
+                    default:
+                        System.out.println("Wrong choice!");
+                }
+            }
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
     }
 }