Add Log based transaction observer

convex-gui/src/main/java/convex/gui/manager/windows/peer/ObserverPanel.java

@@ -7,6 +7,7 @@
 import javax.swing.JPanel;
 import javax.swing.JRadioButton;
 
+import convex.observer.LogObserver;
 import convex.observer.StrimziKafka;
 import convex.peer.Server;
 import convex.peer.TransactionHandler;
@@ -26,6 +27,7 @@ public ObserverPanel(Server server) {
 
 		this.setLayout(new MigLayout("wrap 2"));
 
+		add(new JLabel("Transactions"),"span 2");
 		JRadioButton noneButton=addButton("Transactions",new JLabel("None"),()->{
 			server.getTransactionHandler().setRequestObserver(null);
 			server.getTransactionHandler().setResponseObserver(null);
@@ -42,6 +44,17 @@ public ObserverPanel(Server server) {
 		});
 		add(strmButton);
 		add(new JLabel("Strimzi"));	
+
+		JRadioButton tlogButton=addButton("Transactions",new JLabel("Logs"),()->{
+			TransactionHandler th=server.getTransactionHandler();
+			LogObserver ob=new LogObserver(server);
+			th.setRequestObserver(ob.getTransactionRequestObserver());
+			th.setResponseObserver(ob.getTransactionResponseObserver());
+		});
+		add(tlogButton);
+		add(new JLabel("SLF4J Logging"));	
+
+
 	}
 
 	private JRadioButton addButton(String bgName,JLabel jLabel, Runnable action) {

convex-observer/src/main/java/convex/observer/LogObserver.java

@@ -0,0 +1,34 @@
+package convex.observer;
+
+import java.util.function.BiConsumer;
+import java.util.function.Consumer;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import convex.core.Result;
+import convex.core.data.SignedData;
+import convex.core.transactions.ATransaction;
+import convex.peer.Server;
+
+public class LogObserver {
+	static final Logger log = LoggerFactory.getLogger(LogObserver.class.getName());
+
+	protected Server server;
+
+	public LogObserver(Server server) {
+		this.server=server;
+	}
+
+	public Consumer<SignedData<ATransaction>> getTransactionRequestObserver() {
+		return stx->{
+			log.info("TX Request: {}",stx);
+		};
+	}
+
+	public BiConsumer<SignedData<ATransaction>,Result> getTransactionResponseObserver() {
+		return (tx,r)->{
+			log.info("TX Response: {} for tx {}",r,tx);
+		};
+	}
+}