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While loop in client thread (socket) only entered twice (android)

I'm setting up a client thread for a server/client communication in Android. I can set up the connection juste fine. But when I try looping with the code below the program only enters the while loop twice. (I also tried while(true) but nothing happens...).
I need the thread to wait for the client object to update the sendPicture/sendLinks etc.. to true for to send the example line pw.println("PICTURE").
On the server side (PC) it works juste fine (creating 1 ServerSocket for communication and others for FileTransfers.)
Any help is greatly appreciated.
Already tried: while(true)
public ClientSocketThread(String ip, int port, MainActivity.myClientSocketThreadHandler h, String message, Client c) {
this.IP = ip;
this.message = message;
this.port = port;
this.handler = h;
this.client = c;
this.clientName = c.getClientName();
}
public void run() {
try {
clientSocket = new Socket(this.IP, port);
Scanner is = new Scanner(clientSocket.getInputStream());
pw = new PrintWriter(clientSocket.getOutputStream(), true);
String line = "";
pw.println(message);
while (!line.equals("OVER")) {
Log.i("ClientSocketThread", "------------------In true---------------------------------------------");
if (is.hasNextLine()) {
System.out.println("Has next line");
line = is.nextLine();
}else{
line = "";
}
System.out.println("______________________________Line: " + line);
/**************************
* Connexion établie
*/
if (line.equals("PERMITTED")) {
Message msg = handler.obtainMessage();
msg.what = 1;
Bundle bundle = new Bundle();
bundle.putString("CONNECTION_NAME", this.connectionName);
msg.setData(bundle);
handler.sendMessage(msg);
client.setConnectionAllowed(true);
/**************************
* Connexion refusé
*/
} else if (line.equals("REFUSED")) {
Message msg = handler.obtainMessage();
msg.what = 2;
Bundle bundle = new Bundle();
bundle.putString("CONNECTION_NAME", this.connectionName);
msg.setData(bundle);
handler.sendMessage(msg);
disconnect();
}
/**
* On veut envoyer une image
*/
if (line.startsWith("DSS-PICTURE:")) {
System.out.println("Je suis dans le DDS-PICTURE");
Integer futurServerPort = Integer.valueOf(line.split(":")[1]);
PictureClientSocketThread pictureThread = new PictureClientSocketThread(this.IP, futurServerPort, client.getMyPictureHandler(), "None", client);
pictureThread.run();
}
if (client.getSendLink() == true) {
pw.println("LINK");
System.out.println("_______________________________SEND: LINK");
client.setSendLink(false);
}
if (client.getSendPicture() == true) {
pw.println("PICTURE");
System.out.println("_______________________________SEND: PICTURE");
client.setSendPicture(false);
}
if (client.getSendFile() == true) {
pw.println("FILE");
System.out.println("_______________________________SEND: FILE");
client.setSendFile(false);
}
if (client.getSendVideo() == true) {
pw.println("VIDEO");
System.out.println("_______________________________SEND: VIDEO");
client.setSendVideo(false);
}
}// End while
} catch (
Exception e) {
e.printStackTrace();
}
}
The actual output stops here:
I/---MainActivity: ---------------bind finished
I/ClientSocketThread: ------------------In true---------------------------------------------
I/System.out: Has next line
______________________________Line: PERMITTED
I/ClientSocketThread: ------------------In true---------------------------------------------

https://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#hasNextLine()
This method may block while waiting for input
Probably that's the case.

How to schedule a java code having messageArrived method of MqttCallback

I am new in MQTT world. I have written a code to subscribe a topic and get message from topic and store it in database. Now my problem is how to put this code on server so that it will keep receiving message infinitely. I am trying to create a scheduler but in that case i am Getting Persistence Already in Use error from MQTT. I cannot change the clientId every time it connect. It is a fixed one in my case. Is there any way to get the persistence object which is already connected for a particular clientId?
Please help. Thanks and advance.
Please Find the code subscribe topic and messageArrived method of mqqt to get message from topic
public class AppTest {
private MqttHandler handler;
public void doApp() {
// Read properties from the conf file
Properties props = MqttUtil.readProperties("MyData/app.conf");
String org = props.getProperty("org");
String id = props.getProperty("appid");
String authmethod = props.getProperty("key");
String authtoken = props.getProperty("token");
// isSSL property
String sslStr = props.getProperty("isSSL");
boolean isSSL = false;
if (sslStr.equals("T")) {
isSSL = true;
}
// Format: a:<orgid>:<app-id>
String clientId = "a:" + org + ":" + id;
String serverHost = org + MqttUtil.SERVER_SUFFIX;
handler = new AppMqttHandler();
handler.connect(serverHost, clientId, authmethod, authtoken, isSSL);
// Subscribe Device Events
// iot-2/type/<type-id>/id/<device-id>/evt/<event-id>/fmt/<format-id>
handler.subscribe("iot-2/type/" + MqttUtil.DEFAULT_DEVICE_TYPE
+ "/id/+/evt/" + MqttUtil.DEFAULT_EVENT_ID + "/fmt/json", 0);
}
/**
* This class implements as the application MqttHandler
*
*/
private class AppMqttHandler extends MqttHandler {
// Pattern to check whether the events comes from a device for an event
Pattern pattern = Pattern.compile("iot-2/type/"
+ MqttUtil.DEFAULT_DEVICE_TYPE + "/id/(.+)/evt/"
+ MqttUtil.DEFAULT_EVENT_ID + "/fmt/json");
DatabaseHelper dbHelper = new DatabaseHelper();
/**
* Once a subscribed message is received
*/
#Override
public void messageArrived(String topic, MqttMessage mqttMessage)
throws Exception {
super.messageArrived(topic, mqttMessage);
Matcher matcher = pattern.matcher(topic);
if (matcher.matches()) {
String payload = new String(mqttMessage.getPayload());
// Parse the payload in Json Format
JSONObject contObj = new JSONObject(payload);
System.out
.println("jsonObject arrived in AppTest : " + contObj);
// Call method to insert data in database
dbHelper.insertIntoDB(contObj);
}
}
}
Code to connect to client
public void connect(String serverHost, String clientId, String authmethod,
String authtoken, boolean isSSL) {
// check if client is already connected
if (!isMqttConnected()) {
String connectionUri = null;
//tcp://<org-id>.messaging.internetofthings.ibmcloud.com:1883
//ssl://<org-id>.messaging.internetofthings.ibmcloud.com:8883
if (isSSL) {
connectionUri = "ssl://" + serverHost + ":" + DEFAULT_SSL_PORT;
} else {
connectionUri = "tcp://" + serverHost + ":" + DEFAULT_TCP_PORT;
}
if (client != null) {
try {
client.disconnect();
} catch (MqttException e) {
e.printStackTrace();
}
client = null;
}
try {
client = new MqttClient(connectionUri, clientId);
} catch (MqttException e) {
e.printStackTrace();
}
client.setCallback(this);
// create MqttConnectOptions and set the clean session flag
MqttConnectOptions options = new MqttConnectOptions();
options.setCleanSession(false);
options.setUserName(authmethod);
options.setPassword(authtoken.toCharArray());
//If SSL is used, do not forget to use TLSv1.2
if (isSSL) {
java.util.Properties sslClientProps = new java.util.Properties();
sslClientProps.setProperty("com.ibm.ssl.protocol", "TLSv1.2");
options.setSSLProperties(sslClientProps);
}
try {
// connect
client.connect(options);
System.out.println("Connected to " + connectionUri);
} catch (MqttException e) {
e.printStackTrace();
}
}
}

How to do multiple attempts to upload using SFTP protocol?

In case of file upload fails then how to do multiple attempts while doing SFTP by using JSCH API?
How to ensure file is uploaded successfully?
How to create thread-safe file upload utility?

Create a common static utility method which can be invoked from the external class. This method has a map argument to persist the values of sFTPUser, sFTPHost, sFTPPort, sFTPPwd, destinationLocation and uploadedFileName :
public static void doSFTP(Map<String, String> ftpParameters) {
if (ftpParameters.get("ID_NAME").equals(
NAPSCommonConstants.MFT_NAPSGPCS_INTF)) {
// do sftp for NAPS GPCS Interface.
uploadUsingSFTP(ftpParameters);
}
}
Use synchronized method to ensure thread safety:
private static synchronized void uploadUsingSFTP(
Map<String, String> ftpPrameterList) {
new SFTPUtility().uploadFileMFT(ftpPrameterList.get("sFTPUser"),
ftpPrameterList.get("sFTPHost"), new Integer(ftpPrameterList
.get("sFTPPort")), ftpPrameterList.get("sFTPPwd"),
ftpPrameterList.get("sourceLocation"), ftpPrameterList
.get("destinationLocation"), ftpPrameterList
.get("uploadedFileName"));
}
Responsible method to upload files using SFTP with 5 attempts:
private void uploadFileMFT(String sFTPUser, String sFTPHost, int sFTPPort,
String sFTPPwd, String sourceLocation, String destinationLocation,
String uploadedFileName) {
LOG.info("Inside uploadFileMFT to upload and verify the file.");
JSch jsch = new JSch();
Vector<String> fileList = null;
/** 5 re-attempt logic to get session */
int attempts = 0;
boolean successfulConnect;
do {
try {
successfulConnect = true;
session = jsch.getSession(sFTPUser, sFTPHost, sFTPPort);
LOG.debug("session connected ...");
session.setPassword(sFTPPwd);
Properties config = new Properties();
config.put("StrictHostKeyChecking", "no");
session.setConfig(config);
session.connect();
LOG.debug("Sftp Session connected ...");
channel = session.openChannel("sftp");
LOG.debug("Sftp Channel opened ...");
channelSftp = (ChannelSftp) channel;
channelSftp.connect();
LOG.info(" Sftp channel opened and connected ...");
channelSftp.put(sourceLocation, destinationLocation);
fileList = channelSftp.ls(destinationLocation);
} catch (JSchException e) {
++attempts;
successfulConnect = false;
LOG.error(e);
} catch (SftpException e) {
++attempts;
successfulConnect = false;
LOG.error(e);
} finally {
if (null != channelSftp) {
channelSftp.exit();
LOG.debug(" sftp Channel exited.");
}
if (null != channel) {
channel.disconnect();
LOG.debug(" Channel disconnected.");
}
if (null != session) {
session.disconnect();
LOG.debug(" Host Session disconnected.");
}
}
} while (attempts < 5 && successfulConnect == false);
fileUploadValidation(fileList, uploadedFileName);
LOG.info("Exiting from method - uploadFileMFT ...");
}
Finally uploaded file can be validated:
private void fileUploadValidation (Vector<String> fileList, String uploadedFileName){
boolean isFileExistis = false;
Object[] objArr = fileList.toArray();
for (int i = 0; i < objArr.length; i++) {
String fileName = objArr[i].toString();
isFileExistis = fileName.contains(uploadedFileName);
if (isFileExistis) {
LOG.info("Uploaded file '" + uploadedFileName + "' was transferred successfull ...");
break;
}else if(i >= objArr.length){
LOG.info("Uploaded file '" + uploadedFileName + "' was failed to transfer ...");
}
}
}

Retrieving emails from Latest to oldest Java Mail API

public class testemail {
Properties properties = null;
private Session session = null;
private Store store = null;
private Folder inbox = null;
private String userName = "xxx#gmail.com"; //
private String password = "xxx";
public testemail() {
}
public void readMails() throws Exception {
properties = new Properties();
properties.setProperty("mail.host", "imap.gmail.com");
properties.setProperty("mail.port", "995");
properties.setProperty("mail.transport.protocol", "imaps");
session = Session.getInstance(properties,
new javax.mail.Authenticator() {
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication(userName, password);
}
});
try {
store = session.getStore("imaps");
store.connect();
inbox = store.getFolder("INBOX");
inbox.open(Folder.READ_ONLY);
Message messages[] = inbox.search(new FlagTerm(
new Flags(Flag.SEEN), false));
System.out.println("Number of mails = " + messages.length);
for ( Message message : messages ) {
Address[] from = message.getFrom();
System.out.println("-------------------------------");
System.out.println("Date : " + message.getSentDate());
System.out.println("From : " + from[0]);
System.out.println("Subject: " + message.getSubject());
System.out.println("Content :");
Object content = message.getContent();
Multipart multiPart = (Multipart) content;
procesMultiPart(multiPart);
System.out.println("--------------------------------");
}
inbox.close(true);
store.close();
}
catch (NoSuchProviderException e)
{
e.printStackTrace();
} catch (MessagingException e) {
e.printStackTrace();
}
}
public void procesMultiPart(Multipart content) throws Exception {
int multiPartCount = content.getCount();
for (int i = 0; i < multiPartCount; i++) {
BodyPart bodyPart = content.getBodyPart(i);
Object o;
o = bodyPart.getContent();
if (o instanceof String) {
System.out.println(o);
} else if (o instanceof Multipart) {
procesMultiPart((Multipart) o);
}
}
}
public static void main(String[] args) throws Exception {
testemail sample = new testemail();
sample.readMails();
}}
In the above code I am able to get emails from oldest to newest on my console from gmail. However I would want it to loop from newest to oldest. Is there any way I could get this achieved. Please Help :)

I don't think there's a parameter or method for this in the JavaMail API. You have to reverse the messages array yourself, e.g. by including the Commons.Lang library:
messages = ArrayUtils.reverse(messages);
or iterating over it in the other direction:
for (int i = messages.length - 1; i >= 0; i--) {
Message message = messages[i];

transfer files from unix to windows using java

I want to get a file from unix system to my local system which is on windows using java. I'm very much new to this concept. Any ideas on how it could be done? Which is the best java API for this task?

If the Unix machine supports SFTP, JSch is an option. You could adapt the following code to meet your needs:
private static final String USER_PROMPT = "Enter username#hostname:port";
private static final boolean USE_GUI = true;
public static void main(final String[] arg) {
Session session = null;
ChannelSftp channelSftp = null;
try {
final JSch jsch = new JSch();
final String defaultInput = System.getProperty("user.name") + "#localhost:22";
String input = (USE_GUI) ? JOptionPane.showInputDialog(USER_PROMPT, defaultInput) : System.console().readLine("%s (%s): ", USER_PROMPT, defaultInput);
if (input == null || input.trim().length() == 0) {
input = defaultInput;
}
final int indexOfAt = input.indexOf('#');
final int indexOfColon = input.indexOf(':');
final String user = input.substring(0, indexOfAt);
final String host = input.substring(indexOfAt + 1, indexOfColon);
final int port = Integer.parseInt(input.substring(indexOfColon + 1));
jsch.setKnownHosts("/path/to/known_hosts");
// if you have set up authorized_keys on the server, using that identitiy
// with the code on the next line allows for password-free, trusted connections
// jsch.addIdentity("/path/to/id_rsa", "id_rsa_password");
session = jsch.getSession(user, host, 22);
final UserInfo ui = new MyUserInfo();
session.setUserInfo(ui);
session.connect();
channelSftp = (ChannelSftp) session.openChannel("sftp");
channelSftp.connect();
channelSftp.get("/remotepath/remotefile.txt", "/localpath/localfile.txt");
} finally {
if (channelSftp != null) {
channelSftp.exit();
}
if (session != null) {
session.disconnect();
}
}
}
public static class MyUserInfo implements UserInfo {
private String password;
#Override
public String getPassword() {
return password;
}
#Override
public boolean promptYesNo(final String str) {
final Object[] options = {"yes", "no"};
final boolean yesNo = (USE_GUI) ? JOptionPane.showOptionDialog(null, str, "Warning", JOptionPane.DEFAULT_OPTION, JOptionPane.WARNING_MESSAGE, null, options, options[0]) == 0 : System.console().readLine("Enter y or n: ").equals("y");
return yesNo;
}
#Override
public String getPassphrase() {
return null;
}
#Override
public boolean promptPassphrase(final String message) {
return true;
}
#Override
public boolean promptPassword(final String message) {
if (!USE_GUI) {
password = new String(System.console().readPassword("Password: "));
return true;
} else {
final JTextField passwordField = new JPasswordField(20);
final Object[] ob = {passwordField};
final int result = JOptionPane.showConfirmDialog(null, ob, message, JOptionPane.OK_CANCEL_OPTION);
if (result == JOptionPane.OK_OPTION) {
password = passwordField.getText();
return true;
} else {
return false;
}
}
}
#Override
public void showMessage(final String message) {
if (!USE_GUI) {
System.console().printf(message);
} else {
JOptionPane.showMessageDialog(null, message);
}
}
}

I have found JSch to be very useful and straight foreword. Below is a snippet of code written to put all .txt files in a given folder on the sftp server.
public static void sftpConnection() {
// Object Declaration.
JSch jsch = new JSch();
Session session = null;
Channel channel = null;
// Variable Declaration.
String user = "foo";
String host = "10.9.8.7";
Integer port = 22;
String password = "test123";
String watchFolder = "\\localhost\textfiles";
String outputDir = "/remote/textFolder/";
String filemask = "*.txt";
try {
session = jsch.getSession(user, host, port);
/*
* StrictHostKeyChecking Indicates what to do if the server's host
* key changed or the server is unknown. One of yes (refuse connection),
* ask (ask the user whether to add/change the key) and no
* (always insert the new key).
*/
session.setConfig("StrictHostKeyChecking", "no");
session.setPassword(password);
session.connect();
channel = session.openChannel("sftp");
channel.connect();
ChannelSftp sftpChannel = (ChannelSftp)channel;
// Go through watch folder looking for files.
File[] files = findFile(watchFolder, filemask);
for(File file : files) {
// Upload file.
putFile(file, sftpChannel, outputDir);
}
} finally {
sftpChannel.exit();
session.disconnect();
}
}
public static void putFile(File file, ChannelSftp sftpChannel, String outputDir) {
FileInputStream fis = null;
try {
// Change to output directory.
sftpChannel.cd(outputDir);
// Upload file.
fis = new FileInputStream(file);
sftpChannel.put(fis, file.getName());
fis.close();
} catch{}
}
public static File[] findFile(String dirName, final String mask) {
File dir = new File(dirName);
return dir.listFiles(new FilenameFilter() {
public boolean accept(File dir, String filename)
{ return filename.endsWith(mask); }
} );
}

First thing that goes into my mind is FTP.

There are multiple choices to do that. First one simple socket communication between a java client and a server. If you want to go with this approach then follow this:
http://mrbool.com/file-transfer-between-2-computers-with-java/24516
Then there are other high level protocols implementations that can be used such as FTP, HTTP, etc
Follow a related SO post for java FTP client server: FTP client server model for file transfer in Java