java - 如何通过 java 服务器使用 GCM 向 android 设备发送推送通知？

Question

我正在尝试通过 java 服务器向 android 设备发送推送通知。但是当我部署服务器端代码时，出现以下错误。 java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException:无法启动组件。

package com.avilyne.gcm;

import java.io.IOException;

import java.util.ArrayList;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.google.android.gcm.server.Message;
import com.google.android.gcm.server.MulticastResult;
import com.google.android.gcm.server.Sender;

/**
 * Servlet implementation class GCMBroadcast
 */
@WebServlet("/GCMBroadcast")
public class GCMBroadcast extends HttpServlet {
    private static final long serialVersionUID = 1L;

    // The SENDER_ID here is the "Browser Key" that was generated when I
    // created the API keys for my Google APIs project.
    private static final String SENDER_ID = "AIzaSyD9GblH8c9qCBqDhLPKMca3dH8JsY4cgjg";

    // This is a *cheat*  It is a hard-coded registration ID from an Android device
    // that registered itself with GCM using the same project id shown above.
    private static final String ANDROID_DEVICE = "APA91bEtN2c3FYSFPpW-KuNtkWT6B9NJUviKN0L0DCjviJ2BtMyhZLqsFSFKfsySI1s88I0u68xETjvpqhvepffRSgwoTmpRXAv0Fbr0gH8CLhHO5CJC-M8";

    // This array will hold all the registration ids used to broadcast a message.
    // for this demo, it will only have the ANDROID_DEVICE id that was captured 
    // when we ran the Android client app through Eclipse.
    private List<String> androidTargets = new ArrayList<String>();

    /**
     * @see HttpServlet#HttpServlet()
     */
    public GCMBroadcast() {

        super();

        // we'll only add the hard-coded *cheat* target device registration id 
        // for this demo.
        androidTargets.add(ANDROID_DEVICE);

    }

    // This doPost() method is called from the form in our index.jsp file.
    // It will broadcast the passed "Message" value.
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        // We'll collect the "CollapseKey" and "Message" values from our JSP page
        String collapseKey = "";
        String userMessage = "";

        try {
            userMessage = request.getParameter("Message");
            collapseKey = request.getParameter("CollapseKey");
        } catch (Exception e) {
            e.printStackTrace();
            return;
        }

        // Instance of com.android.gcm.server.Sender, that does the
        // transmission of a Message to the Google Cloud Messaging service.
        Sender sender = new Sender(SENDER_ID);

        // This Message object will hold the data that is being transmitted
        // to the Android client devices.  For this demo, it is a simple text
        // string, but could certainly be a JSON object.
        Message message = new Message.Builder()

        // If multiple messages are sent using the same .collapseKey()
        // the android target device, if it was offline during earlier message
        // transmissions, will only receive the latest message for that key when
        // it goes back on-line.
        .collapseKey(collapseKey)
        .timeToLive(30)
        .delayWhileIdle(true)
        .addData("message", userMessage)
        .build();

        try {
            // use this for multicast messages.  The second parameter
            // of sender.send() will need to be an array of register ids.
            MulticastResult result = sender.send(message, androidTargets, 1);

            if (result.getResults() != null) {
                int canonicalRegId = result.getCanonicalIds();
                if (canonicalRegId != 0) {

                }
            } else {
                int error = result.getFailure();
                System.out.println("Broadcast failure: " + error);
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

        // We'll pass the CollapseKey and Message values back to index.jsp, only so
        // we can display it in our form again.
        request.setAttribute("CollapseKey", collapseKey);
        request.setAttribute("Message", userMessage);

        request.getRequestDispatcher("index.jsp").forward(request, response);

    }

}

Answer 1

试试这个来自谷歌的代码示例

send(String to,String msg){
try {
            // Prepare JSON containing the GCM message content. What to send and where to send.
            JSONObject jGcmData = new JSONObject();
            JSONObject jData = new JSONObject();
            jData.put("message", msg);

             jGcmData.put("to", to);

            // What to send in GCM message.
            jGcmData.put("data", jData);

            // Create connection to send GCM Message request.
            URL url = new URL("https://android.googleapis.com/gcm/send");
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestProperty("Authorization", "key=" + API_KEY);
            conn.setRequestProperty("Content-Type", "application/json");
            conn.setRequestMethod("POST");
            conn.setDoOutput(true);

            // Send GCM message content.
            OutputStream outputStream = conn.getOutputStream();
            outputStream.write(jGcmData.toString().getBytes());

            // Read GCM response.
            InputStream inputStream = conn.getInputStream();
            String resp = IOUtils.toString(inputStream);
            System.out.println(resp);
            System.out.println("Check your device/emulator for notification or logcat for " +
                    "confirmation of the receipt of the GCM message.");
        } catch (IOException e) {
            System.out.println("Unable to send GCM message.");
            System.out.println("Please ensure that API_KEY has been replaced by the server " +
                    "API key, and that the device's registration token is correct (if specified).");
            e.printStackTrace();
        }
}