C2DM, IOException when sending message

I can't get the sending part of C2DM to work. I get IOException at OutputStream out = conn.getOutputStream();

public void sendMessage() throws IOException{       
                String key = readFileAsString("acct/"+to+"/key");

                StringBuilder postDataBuilder = new StringBuilder();
                postDataBuilder.append("registration_id").append("=").append(key);
                postDataBuilder.append("&").append("collapse_key").append("=").append("0");
                postDataBuilder.append("&").append("data.payload").append("=").append(URLEncoder.encode(to+"--"+"acct/"+to+"/1", UTF8));
                byte[] postData = postDataBuilder.toString().getBytes(UTF8);

                URL url = new URL("https://android.apis.google.com/c2dm/send");

                HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                conn.setDoOutput(true);
                conn.setUseCaches(false);
                conn.setRequestMethod("POST");
                conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
                conn.setRequestProperty("Content-Length", Integer.toString(postData.length));                   
                conn.setRequestProperty("Authorization", "GoogleLogin auth=" + cl);

             //------------------
                OutputStream out = conn.getOutputStream();
             //--------------------------
                out.write(postData);
                out.close();

                int sw =conn.getResponseCode();
                System.out.println(""+sw);
                switch (sw) {
                    case 200:
                        System.out.println("Success, but check for errors in the body");
                        break;
                    case 503:
 开发者_StackOverflow社区                       System.out.println("Service unavailable");
                        break;
                    case 401:
                        System.out.println(" Invalid authentication token");
                        break;
                 }

            }

Thank you!

The solution most commonly given to resolve the error message you are receiving is to define a custom Hostname validation. The main problem that you are facing is that the domain name returned by Google's Android URL is *.google.com. Unfortunately, this causes some issues as the Android SDK is at android.apis.google.com. The JVM will not validate this combination by default (*.sdk.google.com would be acceptable).

Here is an example of how you can create your own hostname validator:

    URL url = new URL("https://android.apis.google.com/c2dm/send");

    HostnameVerifier hVerifier = new HostnameVerifier() {
        public boolean verify(String hostname, SSLSession
                session) {
            return true;
        }
    };

    HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
    conn.setHostnameVerifier(hVerifier);

If you change your code to something similar to above, the error you mentioned should be corrected.

EDIT
Here is some test code that is fully functional in my dev environment. Just updated the authentication information with your application specific information to run:

public class C2DMTest {


    public static void main(String... args) throws Exception {
        String auth = authorize();
        if (auth == null) {
            System.out.println("No authorization returned");
            System.exit(1);
        }
        sendMessage(auth);
    }

    /**
     * Perform an authorization request to access Google's C2DM
     * API.
     *
     * @return The retrieved authorization request.
     */
    private static String authorize() throws Exception {
        String accountType = "GOOGLE";
        String service = "ac2dm";

        String source = "replace-me";
        String email = "replace-me";
        String passwd = "replace-me";


        StringBuilder params = new StringBuilder();
        params.append("accountType=").append(accountType)
                .append("&Email=").append(URLEncoder.encode(email, UTF8))
                .append("&Passwd=").append(URLEncoder.encode(passwd, UTF8))
                .append("&service=").append(service)
                .append("&source=").append(source);
        byte[] postData = params.toString().getBytes(UTF8);

        URL url = new URL("https://www.google.com/accounts/ClientLogin");
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setDoOutput(true);
        conn.setDoInput(true);
        conn.setRequestMethod("POST");
        conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
        conn.setRequestProperty("Content-Length", Integer.toString(postData.length));

        //------------------
        OutputStream out = conn.getOutputStream();
        //--------------------------
        out.write(postData);
        out.close();

        int sw = conn.getResponseCode();
        System.out.println("" + sw);

        switch (sw) {
            case 503:
                System.out.println("Service unavailable");
                break;
            case 401:
                System.out.println(" Invalid authentication token");
                break;
            default:
                ByteArrayOutputStream baos = new ByteArrayOutputStream();
                InputStream in = conn.getInputStream();
                byte[] bytes = new byte[100];
                int len = -1;
                while ((len = in.read(bytes)) != -1) {
                    baos.write(bytes, 0, len);
                }
                in.close();
                String input = baos.toString();
                Map<String, String> res = parseResponse(input);
                return res.get("Auth");
        }
        return null;
    }

    /**
     * Parses a response string into a usable data map.
     *
     * @param response The response from Google
     * @return A Map representation.
     */
    private static Map<String, String> parseResponse(String response) {
        Map<String, String> map = new HashMap<String, String>();
        if (response != null) {
            String[] lines = response.split("\n");
            for (String line : lines) {
                String[] parts = line.split("=");
                if (parts.length == 2) {
                    map.put(parts[0], parts[1]);
                }
            }
        }
        return map;
    }

    private static String UTF8 = "UTF-8";


    /**
     * Send message to mobile device.
     *
     * @param cl Google API auth code.
     */
    public static void sendMessage(String cl) throws IOException {
        String key = "invalid";

        StringBuilder postDataBuilder = new StringBuilder();
        postDataBuilder.append("registration_id").append("=").append(key);
        postDataBuilder.append("&").append("collapse_key").append("=").append("0");
        postDataBuilder.append("&").append("data.payload").append("=").append(URLEncoder.encode("test-content", UTF8));
        byte[] postData = postDataBuilder.toString().getBytes(UTF8);

        URL url = new URL("https://android.apis.google.com/c2dm/send");

        HostnameVerifier hVerifier = new HostnameVerifier() {
            public boolean verify(String hostname, SSLSession
                    session) {
                return true;
            }
        };

        HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
        conn.setHostnameVerifier(hVerifier);
        conn.setDoOutput(true);
        conn.setUseCaches(false);
        conn.setRequestMethod("POST");
        conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
        conn.setRequestProperty("Content-Length", Integer.toString(postData.length));
        conn.setRequestProperty("Authorization", "GoogleLogin auth="+cl);

        //------------------
        OutputStream out = conn.getOutputStream();
        //--------------------------
        out.write(postData);
        out.close();

        int sw = conn.getResponseCode();
        System.out.println("" + sw);
        switch (sw) {
            case 200:
                System.out.println("Success, but check for errors in the body");
                break;
            case 503:
                System.out.println("Service unavailable");
                break;
            case 401:
                System.out.println(" Invalid authentication token");
                break;
        }

    }
}