时java.util.Observable中在Android的线程安全的？该文档说，只有deleteObserver（）和deleteObservers（）是同步的方法。怎么样的addObserver（），设置/清除/ hasChanged（）？我可以安全地调用的addObserver（）从不同的线程周围没有可观察的对象锁定？

Is java.util.Observable in Android thread-safe? The documentation says that only deleteObserver() and deleteObservers() are synchronized methods. What about addObserver(), set/clear/hasChanged()? Can I safely call addObserver() from different threads without locking around the Observable object?

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AFAIK，Android的基于Apache和谐。我发现了观测实施和谐这里的来源$ C ​​$ C：http://www.java2s.com/Open-Source/Java-Document/Apache-Harmony-Java-SE/java-package/java/util/Observable.java.htm.

AFAIK, Android is based on Apache Harmony. I found the source code of the the Observable implementation of Harmony here : http://www.java2s.com/Open-Source/Java-Document/Apache-Harmony-Java-SE/java-package/java/util/Observable.java.htm.

在我看来，这将试图使它线程安全的，但没有成功。他们忘了同步countObservers方法，以及设定/有/ clearChanged方法

It seems to me that the tried to make it thread-safe, but failed : they forgot to synchronize the countObservers method, as well as the set/has/clearChanged methods.