working on IMAP listener

src/main/java/de/srsoftware/widerhall/Application.java

@@ -0,0 +1,24 @@
+package de.srsoftware.widerhall;
+
+import org.json.simple.JSONObject;
+import org.json.simple.parser.JSONParser;
+import org.json.simple.parser.ParseException;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+
+public class Application {
+
+    public static void main(String[] args) throws IOException, ParseException {
+        var parser = new JSONParser();
+        var config = Files.readString(new File("/tmp/config.json").toPath());
+        JSONObject json = (JSONObject) parser.parse(config);
+
+        //String testSender = (String) json.get("sender");
+        //String testReceiver = (String) json.get("receiver");
+     //   new SmtpClient(json).send(json,testSender,"Stephan Richter",testReceiver,"Test","Dies ist ein Test");
+        MessageHandler forward = new Forwarder();
+       new ImapClient(json).addListener(forward).start();
+    }
+}

src/main/java/de/srsoftware/widerhall/Constants.java

@@ -0,0 +1,9 @@
+package de.srsoftware.widerhall;
+
+public class Constants {
+    public static final String IMAPS = "imaps";
+    public static final String PROTOCOL = "mail.store.protocol";
+    public static final String HOST = "host";
+    public static final String USER = "user";
+    public static final String PASSWORD = "password";
+}

src/main/java/de/srsoftware/widerhall/Forwarder.java

@@ -0,0 +1,15 @@
+package de.srsoftware.widerhall;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.mail.Message;
+import javax.mail.MessagingException;
+
+public class Forwarder implements MessageHandler {
+    private static final Logger LOG = LoggerFactory.getLogger(Forwarder.class);
+    @Override
+    public void onMessageReceived(Message message) throws MessagingException {
+        LOG.debug("forwarding {}",message.getSubject());
+    }
+}

src/main/java/de/srsoftware/widerhall/ImapClient.java

@@ -0,0 +1,129 @@
+package de.srsoftware.widerhall;
+
+import com.sun.mail.iap.ProtocolException;
+import com.sun.mail.imap.IMAPFolder;
+import com.sun.mail.imap.protocol.IMAPProtocol;
+import org.json.simple.JSONObject;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.mail.*;
+import java.util.HashSet;
+import java.util.Properties;
+
+public class ImapClient {
+
+    private static final Logger LOG = LoggerFactory.getLogger(ImapClient.class);
+    private final JSONObject config;
+    private boolean stopped = false;
+    private IMAPFolder inbox;
+    private HashSet<MessageHandler> listeners = new HashSet<>();
+
+
+
+    private class ListeningThread extends Thread {
+
+        private static final Logger LOG = LoggerFactory.getLogger(ListeningThread.class);
+        private final JSONObject config;
+
+        ListeningThread(JSONObject config){
+            this.config = config;
+        }
+
+        @Override
+        public void run() {
+            while (!stopped) {
+                try {
+                    openInbox();
+                } catch (MessagingException e){
+                    LOG.warn("Connection problem:",e);
+                    try {
+                        sleep(1000);
+                    } catch (InterruptedException interruptedException) {
+                        interruptedException.printStackTrace();
+                    }
+                }
+            }
+        }
+
+        private void openInbox() throws MessagingException {
+            String host = (String) config.get(Constants.HOST);
+            String username = (String) config.get(Constants.USER);
+            String password = (String) config.get(Constants.PASSWORD);
+            LOG.debug("Connecting and logging in…");
+            Properties props = imapProps();
+            Session session = Session.getInstance(props);
+            Store store = session.getStore(Constants.IMAPS);
+            store.connect(host,username,password);
+            LOG.debug("Connected, opening inbox:");
+            inbox = (IMAPFolder)store.getFolder("INBOX");
+            inbox.open(IMAPFolder.READ_WRITE);
+
+            while (!stopped){
+                handleMessages();
+                LOG.debug("Idling.");
+                inbox.idle(true);
+            }
+        }
+
+        private void handleMessages() throws MessagingException {
+            LOG.debug("reading email:");
+            if (!inbox.isOpen()){
+                inbox.open(IMAPFolder.READ_WRITE);
+            }
+            for (Message message : inbox.getMessages()){
+                if (message.isSet(Flags.Flag.SEEN)) continue;
+                handle(message);
+                message.setFlag(Flags.Flag.SEEN,true);
+            }
+        }
+
+        private void handle(Message message) throws MessagingException {
+            LOG.debug("Handling {}",message.getSubject());
+            for (MessageHandler listener : listeners) listener.onMessageReceived(message);
+        }
+
+        private Properties imapProps() {
+            Properties props = new Properties();
+            props.put(Constants.PROTOCOL,Constants.IMAPS);
+            return props;
+        }
+    }
+
+    private class Heartbeat extends Thread{
+
+        private static final Logger LOG = LoggerFactory.getLogger(Heartbeat.class);
+        @Override
+        public void run() {
+            while (!stopped){
+                try {
+                    sleep(300034);
+                    if (inbox != null) continue;
+                    LOG.debug("sending NOOP");
+                    inbox.doCommand(protocol -> {
+                            protocol.simpleCommand("NOOP",null);
+                            return null;
+                    });
+                } catch (InterruptedException | MessagingException e) {
+                    e.printStackTrace();
+                }
+            }
+        }
+    }
+    ImapClient(JSONObject config){
+        this.config = config;
+    }
+
+    public void start() {
+        LOG.debug("Creating ListeningThread…");
+        new ListeningThread(config).start();
+        LOG.debug("Creating Heartbeat…");
+        new Heartbeat().start();
+    }
+
+
+    public ImapClient addListener(MessageHandler messageHandler) {
+        listeners.add(messageHandler);
+        return this;
+    }
+}

src/main/java/de/srsoftware/widerhall/MessageHandler.java

@@ -0,0 +1,8 @@
+package de.srsoftware.widerhall;
+
+import javax.mail.Message;
+import javax.mail.MessagingException;
+
+public interface MessageHandler {
+    public void onMessageReceived(Message message) throws MessagingException;
+}

src/main/java/de/srsoftware/widerhall/SmtpClient.java

@@ -62,13 +62,4 @@ public class SmtpClient {
         LOG.debug("…versendet");
     }
 
-    public static void main(String[] args) throws IOException, ParseException, MessagingException {
-        var parser = new JSONParser();
-        var config = Files.readString(new File("/tmp/config.json").toPath());
-        JSONObject json = (JSONObject) parser.parse(config);
-
-        String testSender = (String) json.get("sender");
-        String testReceiver = (String) json.get("receiver");
-        new SmtpClient(json).send(json,testSender,"Stephan Richter",testReceiver,"Test","Dies ist ein Test");
-    }
 }