Java线程寿命

Question

Suppose I have the following:

public class A
{
    Thread t = new Thread(new Runnable() {
                      @Override
                            public void run() {

                    B b = new B();
                            }
                        });
    }

    class B{
     // long running process and alot of code
    }

The question is that all process and work that class B does goes under thread t or just when the object of class B is created and work of class B starts t is no more available?

Answer 1

The run() method calls the B constructor and then returns. So that's the only thing that happens in the spawned thread: the constructor of B is executed. Having a long process running in a constructor is a serious design smell. Constructors are not meant to execute a long sequence of instructions. They're meant to construct an object.

The code should better look like the followingg:

Thread t = new Thread(new Runnable() {
    @Override
    public void run() {
        B b = new B();
        b.doSomethingLong();
    }
});

Also note that nothing will happen at all if you don't start the thread:

t.start();