如果这样的类在运行时不可用，它会抛出该异常。
If such classes are not available at runtime, it'll throw that exception.
注意，这个文件必须在运行时位于类路径中。
Please note that this file must be in the classpath at runtime.
被引用的keystore文件必须在运行时提供给类路径。
The referenced keystore file must be present in the classpath at run time.
这时将加载您希望使用的类(而不是运行时所使用的类)。
The version you want (instead of the version used by the runtime) is then loaded.
提供用于指定运行时的动态行为的基类。
Provides a base class for specifying dynamic behavior at run time.
我很肯定我们可以在运行时动态地确定类的实例变量。
I'm sure we can dynamically determine iVars of a class at run time.
我很肯定我们可以在运行时动态地确定类的实例变量。
I'm sure we can dynamically determine iVars of a class at run time.
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