Retrofit cannot connect to my local web server on port 3000

Question

My app that is using Retrofit (v1.6.1) to connect to REST web services cannot connect to my local web server (running on localhost), this is the error I am getting.

This is inside Nexus4 (v4.3) emulator, I am using Android Studio for development and I have added android.permission.INTERNET & android.permission.ACCESS_NETWORK_STATE permissions in manifest file.

The error says its waited for 15s but it does not, it errors out right away.

07-13 15:57:53.947      820-840/it.test.android.app.activity D/Retrofit﹕ ---> HTTP POST http://localhost:3000/app/auth/signin
07-13 15:57:54.132      820-840/it.test.android.app.activity D/Retrofit﹕ Content-Type: application/json; charset=UTF-8
07-13 15:57:54.132      820-840/it.test.android.app.activity D/Retrofit﹕ Content-Length: 44
07-13 15:57:54.157      820-840/it.test.android.app.activity D/Retrofit﹕ {"auth":{"email":"steve","password":"pass"}}
07-13 15:57:54.387      820-840/it.test.android.app.activity D/Retrofit﹕ ---> END HTTP (44-byte body)
07-13 15:57:54.657      820-840/it.test.android.app.activity D/Retrofit﹕ ---- ERROR http://localhost:3000/app/auth/signin
07-13 15:57:54.857      820-840/it.test.android.app.activity D/Retrofit﹕ java.net.ConnectException: failed to connect to localhost/127.0.0.1 (port 3000) after 15000ms: isConnected failed: ECONNREFUSED (Connection refused)
            at libcore.io.IoBridge.isConnected(IoBridge.java:223)
            at libcore.io.IoBridge.connectErrno(IoBridge.java:161)
            at libcore.io.IoBridge.connect(IoBridge.java:112)
            at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
            at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
            at java.net.Socket.connect(Socket.java:842)
            at libcore.net.http.HttpConnection.<init>(HttpConnection.java:76)
            at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
            at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)
            at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
            at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
            at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316)
            at libcore.net.http.HttpEngine.connect(HttpEngine.java:311)
            at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
            at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
            at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:81)
            at libcore.net.http.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:197)
            at retrofit.client.UrlConnectionClient.prepareRequest(UrlConnectionClient.java:68)
            at retrofit.client.UrlConnectionClient.execute(UrlConnectionClient.java:37)
            at retrofit.RestAdapter$RestHandler.invokeRequest(RestAdapter.java:321)
            at retrofit.RestAdapter$RestHandler.access$100(RestAdapter.java:220)
            at retrofit.RestAdapter$RestHandler$2.obtainResponse(RestAdapter.java:278)
            at retrofit.CallbackRunnable.run(CallbackRunnable.java:42)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
            at retrofit.Platform$Android$2$1.run(Platform.java:142)
            at java.lang.Thread.run(Thread.java:841)
     Caused by: libcore.io.ErrnoException: isConnected failed: ECONNREFUSED (Connection refused)
            at libcore.io.IoBridge.isConnected(IoBridge.java:208)
            at libcore.io.IoBridge.connectErrno(IoBridge.java:161)
            at libcore.io.IoBridge.connect(IoBridge.java:112)
            at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
            at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
            at java.net.Socket.connect(Socket.java:842)
            at libcore.net.http.HttpConnection.<init>(HttpConnection.java:76)
            at libcore.net.http.HttpConnection.<init>(HttpConnection.java:50)
            at libcore.net.http.HttpConnection$Address.connect(HttpConnection.java:340)
            at libcore.net.http.HttpConnectionPool.get(HttpConnectionPool.java:87)
            at libcore.net.http.HttpConnection.connect(HttpConnection.java:128)
            at libcore.net.http.HttpEngine.openSocketConnection(HttpEngine.java:316)
            at libcore.net.http.HttpEngine.connect(HttpEngine.java:311)
            at libcore.net.http.HttpEngine.sendSocketRequest(HttpEngine.java:290)
            at libcore.net.http.HttpEngine.sendRequest(HttpEngine.java:240)
            at libcore.net.http.HttpURLConnectionImpl.connect(HttpURLConnectionImpl.java:81)
            at libcore.net.http.HttpURLConnectionImpl.getOutputStream(HttpURLConnectionImpl.java:197)
            at retrofit.client.UrlConnectionClient.prepareRequest(UrlConnectionClient.java:68)
            at retrofit.client.UrlConnectionClient.execute(UrlConnectionClient.java:37)
            at retrofit.RestAdapter$RestHandler.invokeRequest(RestAdapter.java:321)
            at retrofit.RestAdapter$RestHandler.access$100(RestAdapter.java:220)
            at retrofit.RestAdapter$RestHandler$2.obtainResponse(RestAdapter.java:278)
            at retrofit.CallbackRunnable.run(CallbackRunnable.java:42)
            at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
            at retrofit.Platform$Android$2$1.run(Platform.java:142)
            at java.lang.Thread.run(Thread.java:841)
07-13 15:57:54.857      820-840/it.test.android.app.activity D/Retrofit﹕ ---- END ERROR

Answer 1

I solved the issue, need to use 10.0.2.2 instead of localhost to connect to my local server.

Found it here - http://developer.android.com/tools/devices/emulator.html#networkaddresses