import java.lang.ref.SoftReference;
public class Test {

    public static void main (String[] args) {
        System.out.println ("开始");

        A a = new A();

        SoftReference<A> sr = new SoftReference<A> (a);
        a = null;
        if (sr != null) {
            a = sr.get();
        } else {
            a = new A();
            sr = new SoftReference<A> (a);
        }

        System.out.println ("结束");
    }


}

class A {
    int[] a ;
    public A() {
        a = new int[100000000];
    }
}