java中this和Thread.currentThread()区别

public class hello extends Thread {

public hello(String name){
super(name);
System.out.println("Thread.currentThread().getname()="+Thread.currentThread().getName());
    System.out.println("This.getName="+this.getName());
    }
public void run(){

    System.out.println("Thread.currentThread().getname()="+Thread.currentThread().getName());

    System.out.println("This.getName="+this.getName());
}
public static void main(String[] args){

 Thread t1=new Thread(new hello("A"));
 t1.setName("B");
 t1.start();
}
}

得到`Thread.currentThread().getname()=main
This.getName=A
Thread.currentThread().getname()=B
This.getName=A`
为什么会得到B和A不一样的名字