Question

I get this exception and I don’t know why, that’s the classes I have:
An activity which starts a service which starts a class which is a ScheduledExecutorService that connect to the db(that’s why the connection thing).

When I tried to connect through my service I understood why I got this exception but now I created a new class/task to do that but I’m still getting this exception.

I didn’t attached code since it’s alot of code and the problem might be in the way I managed this system and not in the code itself, if you would like to see anything else let me know.

---

See Managing a connection to the mysql through a service for more information on why a Thread isn’t appropriate in this case.

EDIT
code attachment:
this is my third class that sends details to the db.

public class SendLocation 
{
    private String lastAddress;
    private int id;
    private Connection conn;
    private PreparedStatement stmt;
    private LocationService ls1;
    private final ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);

    public SendLocation(int id,LocationService ls1)
    {
        this.lastAddress = "";
        this.id = id;
        this.conn = null;
        this.sqlConnect();
        this.sqlInsertStatement();
        this.ls1 = ls1;
    }
    public void send()
    {
        final Runnable sender = new Runnable() 
        {
            public void run() 
            { 
                if(!lastAddress.equals(ls1.getAddress()) && !ls1.getAddress().equals(""))
                {
                    lastAddress = ls1.getAddress();
                    try 
                    {
                        stmt.setInt(1, id);
                        stmt.setString(2, lastAddress);
                        stmt.execute();
                    } 
                    catch (SQLException e) {
                        e.printStackTrace();
                    } 
                }
            }
        };


        final ScheduledFuture sendHandle = 
                scheduler.scheduleAtFixedRate(sender, 1, 1, TimeUnit.SECONDS);

        scheduler.schedule(new Runnable()
        {
            public void run() 
            { 
                sendHandle.cancel(true); 
            }
        }, 60 * 60, TimeUnit.SECONDS);
    }



     public boolean sqlConnect()
        {
            try {
                Class.forName(Config.DRIVER).newInstance();
                DriverManager.setLoginTimeout(100);
                this.conn = DriverManager.getConnection(Config.URL+Config.DBNAME,
                        Config.USERNAME,Config.PASSWORD);
                return true;

            }catch (Exception e) {
                e.printStackTrace();
                return false;
            }
        }
     public void sqlInsertStatement()
     {
         try {
             this.stmt = conn.prepareStatement
                     ("INSERT INTO locations(id, location) VALUES (?,?)");
         }catch (SQLException e1) {
             e1.printStackTrace();
         }
     }
}

EDIT

I changed the task into a thread here is the new code:

public class SendLocation extends Thread
{
    private String lastAddress;
    private int id;
    private Connection conn;
    private PreparedStatement stmt;
    private LocationService ls1;
    private boolean run;

    public SendLocation(int id,LocationService ls1)
    {
        this.lastAddress = "";
        this.id = id;
        this.conn = null;
        this.sqlConnect();
        this.sqlInsertStatement();
        this.ls1 = ls1;
        this.run = true;
    }
    public void run() 
    { 
        while(run)
        {
            if(!lastAddress.equals(ls1.getAddress()) && !ls1.getAddress().equals(""))
            {
                lastAddress = ls1.getAddress();
                try 
                {
                    stmt.setInt(1, id);
                    stmt.setString(2, lastAddress);
                    stmt.execute();
                    sleep(1000);
                } 
                catch (Exception e) {
                    e.printStackTrace();
                } 
            }
        }
    }       
    public void destroy()
    {
        this.run = false;
    }
    public boolean sqlConnect()
    {
        try {
            Class.forName(Config.DRIVER).newInstance();
            DriverManager.setLoginTimeout(100);
            this.conn = DriverManager.getConnection(Config.URL+Config.DBNAME,
                    Config.USERNAME,Config.PASSWORD);
            return true;

        }catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }
     public void sqlInsertStatement()
     {
         try {
             this.stmt = conn.prepareStatement
                     ("INSERT INTO locations(id, location) VALUES (?,?)");
         }catch (SQLException e1) {
             e1.printStackTrace();
         }
     }
}

How come now that I’m getting the NetworkOnMainThread exception??

Answer 1

The exception means that you are performing a long term operation on the UI thread, like a network operation eg. Since android 3, those operations are not allowed and the exception is thrown. So, in order to avoid the exception you should execute your code in a async way. You do not have to create class, but you have to create a class that extend Thread or AsyncTask.