Question

Following is my main class.

public class ShareData {

    /**
     * @param args
     */
    public static void main(String[] args) {
        ShareReader aShareReader = new ShareReader("http://test.com:9000", "[e-mail]", "password");
        Thread fileThread = new Thread(aShareReader);
        fileThread.run(); // fileThread.start() not calling the run() method
    }
}

If I type fileThread.run() run method is called. If I call fileThread.start() the run metod is not called. Following is my thread class. I dont know what I am doing wrong.

public class ShareReader implements Runnable {

    private String itsShareURL =    null;
    private String itsUserId        =   null;
    private String itsPassword      =   null;
    private String itsAuthToken     =   null;
    private String itsLoginURL      =   null;
    private String itsChannelUpateURL   =   null;


    /**
     * 
     */
    public ShareReader(String theShareURL, String theUserId, String thePassword) {
        this.itsShareURL    =   theShareURL;
        this.itsUserId          =   theUserId;
        this.itsPassword        =   thePassword;
        this.itsLoginURL        =   itsShareURL + "/v1.0-SNAPSHOT/login";
        this.itsChannelUpateURL =   itsShareURL + "/v1.0-SNAPSHOT/updateChannelSubscription/";
    }

    public void run() {
        JSONObject json;
        JSONArray jsonArray;
itsAuthToken = getToken(itsUserId, itsPassword);
    updateChannelList(itsAuthToken);

    String aURL = "http://test.com:9000/v1.0-SNAPSHOT/userTimeline/"+itsAuthToken+"/";
    try {
        String lat = null;
        String lon = null;
        String udid = null;
        String dateTime =  null;
        String eventID = null;
        aEventBean = new EventBean();
        jsonArray = readJsonArrayFromUrl(aURL);
        for (int i = 0; i < jsonArray.length(); i++) {
            json = jsonArray.getJSONObject(i);
            lat = json.getString("lat");
            lon = json.getString("lon");
            udid = json.getString("udid");
            eventID = json.getString("eventId");
            dateTime = json.getString("dateTime");
            aEventBean.setItsLatitude(lat);
            aEventBean.setItsLongitude(lon);
            aEventBean.setItsUDID(udid);
            aEventBean.setItsEventIdentifier(eventID);
            aEventBean.setItsDateTime(dateTime);
            System.out.println(udid + " ---> " +lat + " ==== " + lon);
            sendData(aEventBean);
        }
    } catch (IOException e) {
        // TODO Auto-generated catch block

        e.printStackTrace();
    } catch (JSONException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } 
}
}

Sorry If I ask so basic question..
Ideally I need to do fileThread.start() to start a thread..
Thanks in advance…

Answer 1

run() is definitely called if you call start() on fileThread. Check your implementation of run()– its very likely that this method completes or terminates before your check for the print statements. Just an fyi, fileThread.run() is a sequential call while fileThread.start() is a parallel call.

Another vague possibility is that you’re not implementing Java’s runnable; instead, that may be some custom Runnable class in your project.

EDIT:

So apparently calling fileThread.join() helped you fix your problem, but why does this work? If you call fileThread.join(), the main thread waits until the target (in this case, your fileThread object) terminates.