Hi, the intro to the examples states that you need to have the samples server installed in order to see these examples. To install the samples server, you need to select something like "Install samples server" when you are installing the Application Server (not sure if this option exists with GlassFish or not as my GlassFish install is an ant script that doesn't provide an option for a samples server.) If you select Install Samples Server when installing the AppServer, you will see these examples.
For GlassFish, I think that you can get the same samples by downloading them from
https://glassfish-samples.dev.java.net/.
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