軟引用指向的對(duì)象只在內(nèi)存不足時(shí)被回收涨椒，而只被弱引用指向的對(duì)象在下一次GC時(shí)被回收
public class Test {
public static void main(String[] agrs) {
Object obj = new Object();
SoftReference<Object> softReference = new SoftReference<>(obj);
obj = null;
System.gc();
System.out.println("softObjTest, softReference : " + softReference.get());
System.out.println("=================================");
Object obj2 = new Object();
WeakReference<Object> weakReference = new WeakReference<>(obj2);
obj2 = null;//這里不置null奕翔，gc也不會(huì)回收
System.gc();
System.out.println("weakObjTest, weakReference : " + weakReference.get());
}
}
運(yùn)行結(jié)果：
softObjTest, softReference : java.lang.Object@74a14482
=================================
weakObjTest, weakReference : null
Process finished with exit code 0
從運(yùn)行結(jié)果可見懂酱，SoftReference對(duì)象gc也不會(huì)回收脾还，但是WeakReference執(zhí)行g(shù)c時(shí)會(huì)被執(zhí)行回收缕棵。
