java - DocumentBuilderFactory 在 Java 5+ 中是线程安全的吗？

Question

Java 1.4 doc对于 javax.xml.parsers.DocumentBuilderFactory 明确指出:

An implementation of the DocumentBuilderFactory class is NOT guaranteed to be thread safe. It is up to the user application to make sure about the use of the DocumentBuilderFactory from more than one thread. Alternatively the application can have one instance of the DocumentBuilderFactory per thread. An application can use the same instance of the factory to obtain one or more instances of the DocumentBuilder provided the instance of the factory isn't being used in more than one thread at a time.

Java 5和 Java 6然而，文档并没有说这种话。 DocumentBuilderFactory 现在是线程安全的，还是 Sun 只是认为警告是过度的，人们应该更好地了解？

Answer 1

根据单例的文档DocumentBuilderFactory newInstance 方法未同步 然后，DocumentBuilderFactory 在 Java 8 中仍然不是线程安全的...在 Java 11 中都不是.实际上，自 Java 1.4 以来，构造函数并没有改变。