Frage zu Firebase Cloud Messaging

Hallo mc,

Herzlich wilkommen hier im Forum

Es gibt meherere Möglichkeiten FCMs aus einer App zu senden.
Die einfachste wird wohl die FCM Admin API sein: https://firebase.google.com/docs/cloud-messaging/admin/send-messages

Wie speicherst du deine RegistrationIDs der Client Apps? In einer eigenen DB oder in einer Firebase DB?
Du kannst nämlich per Firebase Database die IDs auslesen und dann per Firebase Admin die message senden.

Wenn du das senden lieber manuell vornehmen möchtest, bietet sich auch die HTTP Variante an:
https://firebase.google.com/docs/cloud-messaging/send-message

Hallo mc4735 und herzlich Willkommen hier im Forum

Das ist ganz einfach, erst die Klasse für SSL:

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.Socket;
import java.net.SocketAddress;
import java.net.SocketException;
import java.nio.channels.SocketChannel;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import javax.net.ssl.HandshakeCompletedListener;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLSession;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;


public class NoSSLv3SocketFactory extends SSLSocketFactory {
    private final SSLSocketFactory delegate;

    public NoSSLv3SocketFactory() {
        this.delegate = HttpsURLConnection.getDefaultSSLSocketFactory();
    }

    public NoSSLv3SocketFactory(SSLSocketFactory delegate) {
        this.delegate = delegate;
    }

    @Override
    public String[] getDefaultCipherSuites() {
        return delegate.getDefaultCipherSuites();
    }

    @Override
    public String[] getSupportedCipherSuites() {
        return delegate.getSupportedCipherSuites();
    }

    private Socket makeSocketSafe(Socket socket) {
        if (socket instanceof SSLSocket) {
            socket = new NoSSLv3SSLSocket((SSLSocket) socket);
        }
        return socket;
    }

    @Override
    public Socket createSocket(Socket s, String host, int port, boolean autoClose) throws IOException {
        return makeSocketSafe(delegate.createSocket(s, host, port, autoClose));
    }

    @Override
    public Socket createSocket(String host, int port) throws IOException {
        return makeSocketSafe(delegate.createSocket(host, port));
    }

    @Override
    public Socket createSocket(String host, int port, InetAddress localHost, int localPort) throws IOException {
        return makeSocketSafe(delegate.createSocket(host, port, localHost, localPort));
    }

    @Override
    public Socket createSocket(InetAddress host, int port) throws IOException {
        return makeSocketSafe(delegate.createSocket(host, port));
    }

    @Override
    public Socket createSocket(InetAddress address, int port, InetAddress localAddress, int localPort) throws IOException {
        return makeSocketSafe(delegate.createSocket(address, port, localAddress, localPort));
    }

    private class NoSSLv3SSLSocket extends DelegateSSLSocket {

        private NoSSLv3SSLSocket(SSLSocket delegate) {
            super(delegate);

        }

        @Override
        public void setEnabledProtocols(String[] protocols) {
            if (protocols != null && protocols.length == 1 && "SSLv3".equals(protocols[0])) {

                List<String> enabledProtocols = new ArrayList<String>(Arrays.asList(delegate.getEnabledProtocols()));
                if (enabledProtocols.size() > 1) {
                    enabledProtocols.remove("SSLv3");
                    System.out.println("Removed SSLv3 from enabled protocols");
                } else {
                    System.out.println("SSL stuck with protocol available for " + String.valueOf(enabledProtocols));
                }
                protocols = enabledProtocols.toArray(new String[enabledProtocols.size()]);
            }

            super.setEnabledProtocols(protocols);
        }
    }

    public class DelegateSSLSocket extends SSLSocket {

        protected final SSLSocket delegate;

        DelegateSSLSocket(SSLSocket delegate) {
            this.delegate = delegate;
        }

        @Override
        public String[] getSupportedCipherSuites() {
            return delegate.getSupportedCipherSuites();
        }

        @Override
        public String[] getEnabledCipherSuites() {
            return delegate.getEnabledCipherSuites();
        }

        @Override
        public void setEnabledCipherSuites(String[] suites) {
            delegate.setEnabledCipherSuites(suites);
        }

        @Override
        public String[] getSupportedProtocols() {
            return delegate.getSupportedProtocols();
        }

        @Override
        public String[] getEnabledProtocols() {
            return delegate.getEnabledProtocols();
        }

        @Override
        public void setEnabledProtocols(String[] protocols) {
            delegate.setEnabledProtocols(protocols);
        }

        @Override
        public SSLSession getSession() {
            return delegate.getSession();
        }

        @Override
        public void addHandshakeCompletedListener(HandshakeCompletedListener listener) {
            delegate.addHandshakeCompletedListener(listener);
        }

        @Override
        public void removeHandshakeCompletedListener(HandshakeCompletedListener listener) {
            delegate.removeHandshakeCompletedListener(listener);
        }

        @Override
        public void startHandshake() throws IOException {
            delegate.startHandshake();
        }

        @Override
        public void setUseClientMode(boolean mode) {
            delegate.setUseClientMode(mode);
        }

        @Override
        public boolean getUseClientMode() {
            return delegate.getUseClientMode();
        }

        @Override
        public void setNeedClientAuth(boolean need) {
            delegate.setNeedClientAuth(need);
        }

        @Override
        public void setWantClientAuth(boolean want) {
            delegate.setWantClientAuth(want);
        }

        @Override
        public boolean getNeedClientAuth() {
            return delegate.getNeedClientAuth();
        }

        @Override
        public boolean getWantClientAuth() {
            return delegate.getWantClientAuth();
        }

        @Override
        public void setEnableSessionCreation(boolean flag) {
            delegate.setEnableSessionCreation(flag);
        }

        @Override
        public boolean getEnableSessionCreation() {
            return delegate.getEnableSessionCreation();
        }

        @Override
        public void bind(SocketAddress localAddr) throws IOException {
            delegate.bind(localAddr);
        }

        @Override
        public synchronized void close() throws IOException {
            delegate.close();
        }

        @Override
        public void connect(SocketAddress remoteAddr) throws IOException {
            delegate.connect(remoteAddr);
        }

        @Override
        public void connect(SocketAddress remoteAddr, int timeout) throws IOException {
            delegate.connect(remoteAddr, timeout);
        }

        @Override
        public SocketChannel getChannel() {
            return delegate.getChannel();
        }

        @Override
        public InetAddress getInetAddress() {
            return delegate.getInetAddress();
        }

        @Override
        public InputStream getInputStream() throws IOException {
            return delegate.getInputStream();
        }

        @Override
        public boolean getKeepAlive() throws SocketException {
            return delegate.getKeepAlive();
        }

        @Override
        public InetAddress getLocalAddress() {
            return delegate.getLocalAddress();
        }

        @Override
        public int getLocalPort() {
            return delegate.getLocalPort();
        }

        @Override
        public SocketAddress getLocalSocketAddress() {
            return delegate.getLocalSocketAddress();
        }

        @Override
        public boolean getOOBInline() throws SocketException {
            return delegate.getOOBInline();
        }

        @Override
        public OutputStream getOutputStream() throws IOException {
            return delegate.getOutputStream();
        }

        @Override
        public int getPort() {
            return delegate.getPort();
        }

        @Override
        public synchronized int getReceiveBufferSize() throws SocketException {
            return delegate.getReceiveBufferSize();
        }

        @Override
        public SocketAddress getRemoteSocketAddress() {
            return delegate.getRemoteSocketAddress();
        }

        @Override
        public boolean getReuseAddress() throws SocketException {
            return delegate.getReuseAddress();
        }

        @Override
        public synchronized int getSendBufferSize() throws SocketException {
            return delegate.getSendBufferSize();
        }

        @Override
        public int getSoLinger() throws SocketException {
            return delegate.getSoLinger();
        }

        @Override
        public synchronized int getSoTimeout() throws SocketException {
            return delegate.getSoTimeout();
        }

        @Override
        public boolean getTcpNoDelay() throws SocketException {
            return delegate.getTcpNoDelay();
        }

        @Override
        public int getTrafficClass() throws SocketException {
            return delegate.getTrafficClass();
        }

        @Override
        public boolean isBound() {
            return delegate.isBound();
        }

        @Override
        public boolean isClosed() {
            return delegate.isClosed();
        }

        @Override
        public boolean isConnected() {
            return delegate.isConnected();
        }

        @Override
        public boolean isInputShutdown() {
            return delegate.isInputShutdown();
        }

        @Override
        public boolean isOutputShutdown() {
            return delegate.isOutputShutdown();
        }

        @Override
        public void sendUrgentData(int value) throws IOException {
            delegate.sendUrgentData(value);
        }

        @Override
        public void setKeepAlive(boolean keepAlive) throws SocketException {
            delegate.setKeepAlive(keepAlive);
        }

        @Override
        public void setOOBInline(boolean oobinline) throws SocketException {
            delegate.setOOBInline(oobinline);
        }

        @Override
        public void setPerformancePreferences(int connectionTime, int latency, int bandwidth) {
            delegate.setPerformancePreferences(connectionTime, latency, bandwidth);
        }

        @Override
        public synchronized void setReceiveBufferSize(int size) throws SocketException {
            delegate.setReceiveBufferSize(size);
        }

        @Override
        public void setReuseAddress(boolean reuse) throws SocketException {
            delegate.setReuseAddress(reuse);
        }

        @Override
        public synchronized void setSendBufferSize(int size) throws SocketException {
            delegate.setSendBufferSize(size);
        }

        @Override
        public void setSoLinger(boolean on, int timeout) throws SocketException {
            delegate.setSoLinger(on, timeout);
        }

        @Override
        public synchronized void setSoTimeout(int timeout) throws SocketException {
            delegate.setSoTimeout(timeout);
        }

        @Override
        public void setTcpNoDelay(boolean on) throws SocketException {
            delegate.setTcpNoDelay(on);
        }

        @Override
        public void setTrafficClass(int value) throws SocketException {
            delegate.setTrafficClass(value);
        }

        @Override
        public void shutdownInput() throws IOException {
            delegate.shutdownInput();
        }

        @Override
        public void shutdownOutput() throws IOException {
            delegate.shutdownOutput();
        }

        @Override
        public String toString() {
            return delegate.toString();
        }

        @Override
        public boolean equals(Object o) {
            return delegate.equals(o);
        }
    }
}

und dann die Klasse:

import android.os.AsyncTask;
import android.util.Log;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;

import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocketFactory;

public class FCMSSL extends AsyncTask<String, String, String> {

    private String _postParam = "{\"to\":\"FCM_ID_VOM_EMPFAENGER\",\"data\":{\"title\":\"Nachrichtensystem\"}}";
    private String _url = "https://fcm.googleapis.com/fcm/send";
    private boolean _debug = false;
    private String _contentType = "application/json";
    private int _timeout = 7000;
    private String TAG = FCMSSL.class.getSimpleName();


    @Override
    protected String doInBackground(String... params) {
        URL url;
        try {
            Log.e(TAG, _postParam);
            SSLContext sslcontext = SSLContext.getInstance("TLSv1");
            sslcontext.init(null, null, null);
            SSLSocketFactory NoSSLv3Factory = new NoSSLv3SocketFactory(sslcontext.getSocketFactory());
            HttpsURLConnection.setDefaultSSLSocketFactory(NoSSLv3Factory);
            url = new URL(_url);
            HttpsURLConnection con = (HttpsURLConnection) url.openConnection();

            con.setReadTimeout(_timeout);
            con.setConnectTimeout(_timeout);
            con.setDoOutput(true);
            con.setDoInput(true);
            con.setInstanceFollowRedirects(false);
            con.setRequestMethod("POST");
            if (_postParam != null)
                con.setFixedLengthStreamingMode(_postParam.getBytes().length);
            else
                Log.d(TAG + " - postParam", "Empty");
            con.setRequestProperty("Content-Type", _contentType);
            con.setRequestProperty("Authorization", "key=DEIN_SERVER_KEY");
            // Send
            PrintWriter out = new PrintWriter(con.getOutputStream());
            if (_postParam != null)
                out.print(_postParam);
            else
                Log.d(TAG + " - postParam", "Empty");
            out.close();

            con.connect();
            BufferedReader in = null;
            if (con.getResponseCode() != 200) {
                in = new BufferedReader(new InputStreamReader(con.getErrorStream()));
                Log.d(TAG, "!=200: " + in.readLine());
                return in.readLine();
            } else {
                in = new BufferedReader(new InputStreamReader(con.getInputStream()));
                Log.d(TAG, "POST request send successful: " + in.readLine());
            }
        } catch (IOException e) {
            Log.e(TAG + " - IOException", e.getMessage());
        } catch (NoSuchAlgorithmException e) {
            Log.e(TAG + " - NoSuchAlgorithm", e.getMessage());
        } catch (KeyManagementException e) {
            Log.e(TAG + " - KeyManagement", e.getMessage());
        }
        return null;
    }
}