1、代码取消强引用后，gc回收对象
public static void main(String[] args) {Object obj = new Object();WeakReference<Object> weakRef = new WeakReference<>(obj);System.out.println(weakRef.get());obj = null; System.gc(); System.out.println(weakRef.get());if (weakRef.get() == null) {System.out.println("对象已经被回收");} else {System.out.println("对象仍然存在");}}
2、不取消强引用，gc无法回收
public static void main(String[] args) {Object obj = new Object();WeakReference<Object> weakRef = new WeakReference<>(obj);System.out.println(weakRef.get());System.gc(); System.out.println(weakRef.get());if (weakRef.get() == null) {System.out.println("对象已经被回收");} else {System.out.println("对象仍然存在");}}
3、总结，将对象设置为null可结束强引用，保证能够被回收。
