android: cannot resolve method sendMessage(androd.os.message) - android-handler

Question

I am stuck when learning handlers. The following is my simple code:
public class MainActivity extends AppCompatActivity {
Thread thread;
public Handler handler;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.content_main);
thread = new Thread(new MyThread());
thread.start();
handler=new Handler() {
#Override
public void close() {
}
#Override
public void flush() {
}
#Override
public void publish(LogRecord record) {
}
};
}
class MyThread implements Runnable{
#Override
public void run(){
Message message=Message.obtain();
for(int i=0;i<10000;i++){
handler.sendMessage(message);
}
}
}
}
In the MyThread class, i was trying to type sendMessage after handler. but android studio does not show any such sendMessage option. still i typed it, then it shows in red. and says cannot resolve method.

Answer 1

You have imported wrong handler class
import java.util.logging.Handler;
And sendMessage method does not belong to this class
Try this import android.os.Handler;
Example:
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.ProgressBar;
public class MainActivity extends AppCompatActivity {
Thread thread;
Handler handler;
ProgressBar progressbar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
progressbar = (ProgressBar) findViewById(R.id.progressbar1);
thread = new Thread(new MyThread());
thread.start();
handler = new Handler() {
public void handleMessage(Message msg) {
progressbar.setProgress(msg.arg1);
};
};
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
}
class MyThread implements Runnable {
#Override
public void run() {
Message message = Message.obtain();
Log.d("message", "" + message);
for (int i = 0; i < 100; i++) {
message.arg1 = i;
handler.sendMessage(message);
try {
Thread.sleep(100);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}