如何避免嵌套同步和由此产生的死锁

尽管您保留了锁定顺序，但是如果将obj1与obj2切换，则会遇到死锁。

您必须寻找另一种解决方案来避免这种情况：锁定顺序+可选的打破平局锁定

int fromHash = System.identityHashCode(obj1);int toHash = System.identityHashCode(obj2);if (fromHash < toHash) {    synchronized (obj1) {        synchronized (obj2) {    ........        }    }} else if (fromHash > toHash) {    synchronized (obj2) {        synchronized (obj1) { ........        }    }} else {    synchronized (TIE_LOCK) {        synchronized (fromAcct) { synchronized (toAcct) {    ... }        }    }