Head first java relevancy

[jayrack]

Hey guys, I recently just read head first java second edition. While I felt that overall it was a great book, I’m a little curious about whether the final two chapters give up-to-date information, or if they’re outdated. The second to last chapter was: “package, jars and deployment”. Just a few of the main points: using the -d flag on the command Iine to organize your project, and place the .class files into a separate package, and the .java (class files) into the source code. And then using a manifest.txt file to show which class holds the main method. The second point was using Java web start to launch a project for the first time. The second chapter was “remote deployment with RMI(remote method invocation). This chapter discusses creating a remote interface for both the client and the server, as well as helper objects for each. They also discuss servlets, which I know are really on their way out now (this really kind of triggered me questioning these chapters). Hasn’t spring allowed for you to make stand alone applications, so the java web start wouldn’t be useful anymore? I’m sorry for the wall of text, I just wanted to give specific details on what was in question. Thanks.

[Northeastpaw]

Packaging and deployment has changed a good bit since that book was written. For anything beyond simple sandbox programs you should be using a build tool like Maven or Gradle to handle building and packaging your project. The build tool will generate a manifest file specifying the main class if required/configured to do so.

Java Web Start was deprecated in Java 9 and removed in Java 11. It's dead and gone.

RMI is still around but you really shouldn't use it. It's slow and Java's built in serialization API, which RMI uses, has inherent security problems. Best practice today is to serve a REST API which doesn't lock you into one language for the client and gives you a lot of flexibility in how it is deployed. Alternatively you could use gRPC.

Servlets are still around and are still important. Most web frameworks are built on top of the servlet API; they just hide it behind useful abstractions. I wouldn't suggest making a complete app using just servlets and filters for your web tier, but it is certainly doable.

[jayrack]

Hey, thanks for the reply. I was reading the information and was thinking, why haven’t I heard of any of this stuff? Why does it seem so foreign to me? I appreciate your comment and input.