急！！！！大家帮忙解决一下！！！!

Class   Test{
public   void   a(){
System.out.println( "a   method   is   running ");
}
public   void   b(){
for(int   i=0;;i++){
System.out.println(i+ "is   running ");
}

}
public   static   void   main(String[]   args){
//如何让a()每两秒执行一次，穿插在b()的执行结果中
}
}
我想得到的结果是：
a   method   is   running
1   is   running
2   is   running
3   is   running
......//2秒后再次执行a()
a   method   is   running
140   is   running
141   is   running
......//2秒后再次执行a()
a   method   is   running
270   is   running
271is   running
....//2秒后再次执行a()

------解决方案--------------------
class Test{
public void a(){
System.out.println( "a method is running ");
}
public void b(){
for(int i=0;;i++){
System.out.println(i+ "is running ");

//还是小睡一会吧，否则打得太快，眼花瞭乱的，你根本啥也看不清。
try { Thread.sleep(200); } catch(Exception e) {};
}

}
public static void main(String[] args){
//如何让a()每两秒执行一次，穿插在b()的执行结果中

final Test t = new Test();
new Thread(new Runnable() {
public void run() {
t.b();
}
}).start();

new Thread(new Runnable(){
public void run() {
while(true) {
t.a();
try { Thread.sleep(2000); } catch(Exception e) {};
}
}
}).start();
}
}
------解决方案--------------------
内部类访问的局部变量必需声明为final最终类型

new Thread(new Runnable() {
public void run() {
t.b(); // 访问的局部变量
}
}).start();