使用双花括号初始化集合，可别这么干

public class A {

    private String name;

    public A(String name) {
        this.name = name;
    }

    public Map<String, String> getMap() {
        return new HashMap<String, String>() {
            private static final long serialVersionUID = -3309655755403147761L;

            {
            put("name", name);
        }};

    }

    public Map<String, String> getMap1() {
        return new HashMap<String, String>();
    }

    @Override
    protected void finalize() throws Throwable {
        System.out.println("Thread name: " + Thread.currentThread().getName() + " Object: " + this.name + " Gc happen");
        super.finalize();
    }
}

public class B {

    private Map<String, String> map;

    public B(Map<String, String> map) {
        this.map = map;
    }
}

public class Test {
    public static void main(String[] args) throws InterruptedException {
        A a = new A("bob");
        final B b = new B(a.getMap());
        System.out.println("访问外部类对象的属性：" + b.getMap().get("name"));
        a = null;
        System.gc();
        Thread.sleep(1000);

        A a1 = new A("sandy");
        final B b1 = new B(a1.getMap1());
        a1 = null;
        System.gc();
        Thread.sleep(1000);
    }
}

访问外部类对象的属性：bob
Thread name: Finalizer Object: sandy Gc happen