Android AsyncTask called "multiple" times -

i'm new android programming. have main activity gets data db through service handler (url). want insert data well, on different activity, , want main activity date each time been called (onresume(),onrestart()). i've found on android api reference asynctask: the task can executed once (an exception thrown if second execution attempted.) mean cannot call asynctask whenever activity resumes, or cannot have multiple "instances" of asynctask running @ same time?

it literally means, while asynctask running, cannot launch again. in mainactivity.class have line:

task.execute();  

if task either finished or not , call method again exception thrown.

and put method in onresume() practice. 1 thing notice is: if put in onrestart() remember, callback works when change configuration, not called if create activity.

the doc lifecycle of activity.