Today, when I use Android’s own refresh control, I need a handler for instance calls, but I report an error in my own instance calls
“handler” is abstract; can’t be identified
because there is an error in my import library. I use Android’s handler library instead of Java’s handle library
the solution is as follows
use “import” to import android.os.Handler ; ”Replace “import” java.util.logging .Handler;”

This can be solved, in addition to the reference to this blog