Reddit mentions of Patterns of Enterprise Application Architecture (Addison-Wesley Signature Series (Fowler))

You need to understand there are a couple of ways to do Java web development.

• Servlets & JSPs. - Check out Core Servlets and JavaServer Pages or the Java EE Tutorial. Note that I link to an older EE tutorial because the newer versions try to switch to JSF and not much changed in Servlets and JSPs between Java EE 5 and 6. I recommend learning Servlets and JSPs before anything else.
  
• JSF - A frameworks that is layered on top of Servlets and JSPs. Works well for some tasks like making highly form centric business web apps. Most of the JSF 2 books are okay. JSF is covered in the Java EE 6 Tutorial
  
• Spring - Spring is actually a bunch of things. You'd want to learn Spring MVC. If you learn any server-side Java web tech besides Servlets and JSPs you'd probably want to learn Spring MVC. I wouldn't bother with GWT or any other server-side Java web tech.
  
• JAX-RS - After you get Servlets and JSPs down, this is the most essential thing for you to learn. More and more you don't use server-side Java (Servlets & JSPs) to generate your clients HTML and instead you use client-side JavaScript to make AJAX calls to a Java backend via HTTP/JSON. You'll probably spend more time with JavaScript:The Good Parts and JavaScript: The Definitive Guide than anything else. Also the JAX-RS api isn't that hard but designing a good RESTful api can be so be on the lookout for language agnostic REST books.
  
  Definitely learn Hibernate. You can start with the JPA material in the Java EE tutorial.
  
  As for design patterns, Design Patterns: Elements of Reusable Object-Oriented Software is a classic. I also like Patterns of Enterprise Application Architecture for more of an enterprise system pattern view of things. Probably avoid most J2EE pattern books. Most of the Java EE patterns come about because of deficiencies of the J2EE/JavaEE platform. As each new version of Java EE comes out you see that the patterns that have arisen become part for the platform. For example you don't create a lot of database DAOs because JPA/Hibernate handles your database integration layer. You also don't write a lot of service locators now because of CDI. So books like CoreJ2EE Patterns can interesting but if you are learning a modern Java web stack you'll be amazed at how archaic things used to be if you look at old J2EE pattern books.
  
  p.s. Don't buy anything that says J2EE, it'll be seven years out of date.
  

If you are working on a small project with three tables, you don't need to worry too much. The problems arise when you have a large system where good architecture and appropriate patterns become really important.

With AR, the model class is responsible for both a) modelling a domain object and b) saving it to the DB and loading it back. Which means the model class gets mixed with methods like beforeSave, afterSave and afterFind to turn DB column values into your domain values and back (e.g. timestamps and datetimes converted to DateTime, complete with some timezone). This breaks the Single Responsibility Principle. Note: this is not a big deal for a small solution where your business logic is simple, but it tends to get worse as the system grows.

If an attribute holds something more complex than a string/number (e.g. a DateTime, a custom Money class, etc.), you have to manually (un)stringify it using beforeSave and afterSave (or stow the original value away somewhere in an additional private property).

• Are you sure those conversions are lossless (of course they should be, but are you certain, especially with datetime/timezones)? I've been bitten by (my own fault) fun bugs before where a DateTime was constructed with a local timezone, then (correctly, by design) saved and unstringified into a DateTime with UTC, and suddenly that entity's publication date is different than it was before...
  
• What happens if there's an exception thrown between beforeSave and afterSave - what state is your model left in? Personally, I am not fond of a property that can be both a string and an object at different times.
  
  See also: Martin Fowler - Patterns of Enterprise Applications.

Hi,

Can somebody recommend me good books/sources for the following-:

1.Advanced Design Patterns - OOPS + Functional
2.Refactoring
3.Big data analytics and ML algorithms
4.Any fast track course/refresher for JS + Angular(Im looking for something that has finer details,ive done JS in the past but ive forgotten most of it)

Also,ive picked up on some of Martin Fowlers books for now,but would like more perspective-:

https://www.csie.ntu.edu.tw/~r95004/Refactoring_improving_the_design_of_existing_code.pdf

http://www.amazon.in/Enterprise-Application-Architecture-Addison-Wesley-Signature-ebook/dp/B008OHVDFM

Would highly recommend these for anyone interested..

i, myself, have been looking into this and often find Martin Fowler referenced: https://www.amazon.com/Enterprise-Application-Architecture-Addison-Wesley-Signature-ebook/dp/B008OHVDFM?ie=UTF8&me=&ref_=mt_kindle