Add IP discovery.

Before a client wants to join a network, it may send a HTTP "ping"
request to a known participant. The participant will send a HTTP "pong"
request in response, which informs the client of its IP address.

The IP address of a client is automatically retrieved from the first
HTTP request received by Jetty.

3 files changed, 42 insertions, 14 deletions

diff --git a/jsonrpc/src/main/java/com/orbekk/rpc/App.java b/jsonrpc/src/main/java/com/orbekk/rpc/App.java
index d92003e..0e9dce3 100644
--- a/jsonrpc/src/main/java/com/orbekk/rpc/App.java
+++ b/jsonrpc/src/main/java/com/orbekk/rpc/App.java
@@ -28,7 +28,7 @@ public class App {
                 SameService.class);   
     
         Server server = new Server(port);
-        RpcHandler rpcHandler = new RpcHandler(jsonServer, service);
+        RpcHandler rpcHandler = new RpcHandler(jsonServer, sameState);
         server.setHandler(rpcHandler);
 
         try {
diff --git a/jsonrpc/src/main/java/com/orbekk/rpc/Client.java b/jsonrpc/src/main/java/com/orbekk/rpc/Client.java
index ea63fd7..2ec6c89 100644
--- a/jsonrpc/src/main/java/com/orbekk/rpc/Client.java
+++ b/jsonrpc/src/main/java/com/orbekk/rpc/Client.java
@@ -5,6 +5,7 @@ import com.orbekk.same.ConnectionManagerImpl;
 import com.orbekk.same.SameState;
 import com.orbekk.same.SameService;
 import com.orbekk.same.SameServiceImpl;
+import com.orbekk.net.HttpUtil;
 import java.net.MalformedURLException;
 import java.net.URL;
 import org.eclipse.jetty.server.Server;
@@ -33,7 +34,7 @@ public class Client {
                 SameService.class);   
     
         Server server = new Server(port);
-        RpcHandler rpcHandler = new RpcHandler(jsonServer, service);
+        RpcHandler rpcHandler = new RpcHandler(jsonServer, sameState);
         server.setHandler(rpcHandler);
 
         try {
@@ -42,11 +43,20 @@ public class Client {
             System.out.println("Could not start jetty server.");
             e.printStackTrace();
         }
+
+        while (sameState.getUrl() == null) {
+            HttpUtil.sendHttpRequest(remoteAddr + "ping?port=" + port);
+            try {
+                Thread.sleep(500);
+            } catch (InterruptedException e) {
+                // Ignore interrupt in wait loop.
+            }
+        }
         
         SameService remoteService = connections.getConnection(remoteAddr);
         remoteService.notifyNetwork("NoNetwork");
         remoteService.participateNetwork("FirstNetwork",
-                sameState.getClientId(), "", port);
+                sameState.getClientId(), sameState.getUrl());
 
         try {
             server.join();
diff --git a/jsonrpc/src/main/java/com/orbekk/rpc/RpcHandler.java b/jsonrpc/src/main/java/com/orbekk/rpc/RpcHandler.java
index 39676fe..0bafad4 100644
--- a/jsonrpc/src/main/java/com/orbekk/rpc/RpcHandler.java
+++ b/jsonrpc/src/main/java/com/orbekk/rpc/RpcHandler.java
@@ -1,34 +1,52 @@
 package com.orbekk.rpc;
 
+import com.googlecode.jsonrpc4j.JsonRpcServer;
+import com.orbekk.net.HttpUtil;
+import com.orbekk.same.UrlReceiver;
 import java.io.IOException;
-
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
-
 import org.eclipse.jetty.server.Request;
 import org.eclipse.jetty.server.handler.AbstractHandler;
-
-import com.googlecode.jsonrpc4j.JsonRpcServer;
-import com.orbekk.same.CallerInfoListener;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 public class RpcHandler extends AbstractHandler {
+    private Logger logger = LoggerFactory.getLogger(getClass());
     private JsonRpcServer rpcServer;
-    private CallerInfoListener callerInfoListener;
+    private UrlReceiver urlReceiver;
     
     public RpcHandler(JsonRpcServer rpcServer,
-            CallerInfoListener callerInfoListener) {
+            UrlReceiver urlReceiver) {
         this.rpcServer = rpcServer;
-        this.callerInfoListener = callerInfoListener;
+        this.urlReceiver = urlReceiver;
     }
     
     @Override
     public synchronized void handle(String target, Request baseRequest,
             HttpServletRequest request, HttpServletResponse response)
             throws IOException, ServletException {
-        if (callerInfoListener != null) {
-            callerInfoListener.setCaller(request.getRemoteAddr());
+        logger.info("Handling request to target: " + target);
+
+        if (urlReceiver != null) {
+            String sameServiceUrl = "http://" + request.getLocalAddr() + 
+                ":" + request.getLocalPort() + "/SameService.json";
+            urlReceiver.setUrl(sameServiceUrl);
+            urlReceiver = null;
+        }
+
+        if (target.equals("/ping")) {
+            int remotePort = Integer.parseInt(request.getParameter("port"));
+            String pongUrl = "http://" + request.getRemoteAddr() + ":" +
+                remotePort + "/pong";
+            logger.info("Got ping. Sending pong to {}", pongUrl);
+            HttpUtil.sendHttpRequest(pongUrl);
+        } else if (target.equals("/pong")) {
+            logger.info("Received pong from {}", request.getRemoteAddr());
+        } else {
+            rpcServer.handle(request, response);
         }
-        rpcServer.handle(request, response);
+        baseRequest.setHandled(true);
     }
 }