我注意到您可以指定< package /> JNLP中的属性如下所示：
http://lopica.sourceforge.net/ref.html#package

与让applet类加载器完成工作相比,显式定义它们有什么优点？

解决方法:

JSR-56规范说明了原因：

http://jcp.org/aboutJava/communityprocess/mrel/jsr056/index5.html

4.5 Package Element

…

The package element only makes sense to use with lazily-downloaded
resources, since all other resources will already be available to the
JVM. Thus, it will already know what packages are implemented in those
JAR files. However, it can direct the JNLP Client to download the
right lazy JAR resources, instead of having to download each
individual resource one at a time to check.