Add a tool to watch for broadcasts of rotation transactions.

tools/src/main/java/com/google/bitcoin/tools/WatchMempool.java

@@ -0,0 +1,32 @@
+package com.google.bitcoin.tools;
+
+import com.google.bitcoin.core.*;
+import com.google.bitcoin.discovery.DnsDiscovery;
+import com.google.bitcoin.params.MainNetParams;
+import com.google.bitcoin.utils.BriefLogFormatter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class WatchMempool {
+    private static Logger log = LoggerFactory.getLogger(WatchMempool.class);
+
+    public static void main(String[] args) {
+        BriefLogFormatter.init();
+        NetworkParameters params = MainNetParams.get();
+        PeerGroup peerGroup = new PeerGroup(params);
+        peerGroup.addPeerDiscovery(new DnsDiscovery(params));
+        peerGroup.addEventListener(new AbstractPeerEventListener() {
+            @Override
+            public void onTransaction(Peer peer, Transaction tx) {
+                try {
+                    if (tx.getOutputs().size() != 1) return;
+                    if (!tx.getOutput(0).getScriptPubKey().isSentToRawPubKey()) return;
+                    log.info("Saw raw pay to pubkey {}", tx);
+                } catch (ScriptException e) {
+                    e.printStackTrace();
+                }
+            }
+        });
+        peerGroup.start();
+    }
+}