Questions integrating new Groovy template engine with Spring MVC and Spring Boot - spring

As blogged on spring.io both Spring 4.1 and Sprig Boot will integrate the new Groovy template engine (https://spring.io/blog/2014/05/28/using-the-innovative-groovy-template-engine-in-spring-boot, http://spring.io/blog/2014/07/28/spring-framework-4-1-spring-mvc-improvements).
I wonder the following:
Will Spring provide something like it does with the Spring Forms and Spring Security taglib?
If not what would be best to e.g. render form fields and more importantly form errors?
I think without it it will be a step back to develop a traditional Spring MVC webapp.
The template engine suports something like a BaseTemplate (see http://mrhaki.blogspot.nl/2014/08/groovy-goodness-use-custom-template.html) where it would be possible to provide custom methods to the template engine.
Related to this:
You can only provdide a single base template, so it will be difficult to include methods from multiple extension points. E.g. Spring Forms, Spring Security and multiple custom extensions like Fontawesome.
Is it possible to set the base template with Spring Boot?

A simple way to expose a lot of the spring specific attributes csrf etc... is to include spring.groovy.template.expose-request-attributes = true in your application.properties

Related

Spring MVC modules,subsystems and components

Let's say we have a Spring MVC project which is a banking web application. I am trying to identify the sub-systems ,modules and components of this project.
1.Subsystems - from what I have red the subsystems in MVC architecture are only 3- the Model,View and Controller is that correct?
2.Modules - are these a group of classes that do something particular as a group.For example LoginController.java,RegisterControler.java form a module let's call it Authentication
3.Components - for components I am not sure which they are in a Spring MVC project.
If someone can explain with examples in terms of a banking web application or other Spring MVC app it would be great!
Spring MVC follows the Model-View-Controller design pattern.
Model - A model contains the data of the application. A data can be a single object or a collection of objects.
Controller - A controller contains the business logic of an application. Here, the #Controller annotation is used to mark the class as the controller.
View - A view represents the provided information in a particular format. Generally, JSP+JSTL is used to create a view page. Although spring also supports other view technologies such as Apache Velocity, Thymeleaf and FreeMarker.
Spring Boot Framework has mainly four major Components.
Spring Boot Starters.
Spring Boot AutoConfigurator.
Spring Boot CLI.
Spring Boot Actuator.
Please check out : https://www.journaldev.com/7989/key-components-and-internals-of-spring-boot-framework
In project-specific terms,
Module: It can be something that can be built separately in an application. ex: Login Module, Sign-up module, Transactions module, etc., You can say a module is a group of components.
Sub-systems: As far as I know, subsystems are the service package related stuff.
Components: Annotating a class with #Component tells Spring that it is available for fulfilling injections.
Spring Component annotation is used to denote a class as a Component. It means that the Spring framework will autodetect these classes for dependency injection when annotation-based configuration and classpath scanning is used

Are there similar tags like <form:select> and <form:option> tags in spring boot?

is there something similar to tags and tags in spring boot? I should make a following page:
I was considering to use SimpleFormController but it exists in Spring MVC. In my current project we are using spring boot + jsp (Now I am considering thymleaf, but I prefer to use jsp, we have already used it). May be you can give me some useful advice, in any way I will appreciate you for help.

thymeleaf vs thymeleaf-spring4 dependency

Question is simple, what is the difference between the above dependencies? Does the first one enough for a springboot app or the second contains something special?
Artifact thymeleaf is the Core library.
Artifact thymeleaf-spring4 allows to integrate Thymeleaf with the Spring Framework, especially (but not only) Spring MVC. Btw there are several Thymeleaf integration packages for different Spring versions are available at the moment:
thymeleaf-spring3, thymeleaf-spring4, thymeleaf-spring5.
Information from thymeleaf-spring official documentation:
Thymeleaf offers a set of Spring integrations that allow you to use it as a fully-featured substitute for JSP in Spring MVC applications.
These integrations will allow you to:
Make the mapped methods in your Spring MVC #Controller objects forward to templates managed by Thymeleaf, exactly like you do with JSPs.
Use Spring Expression Language (Spring EL) instead of OGNL in your templates.
Create forms in your templates that are completely integrated with your form-backing beans and result bindings, including the use of property editors, conversion services and validation error handling.
Display internationalization messages from message files managed by Spring (through the usual MessageSource objects).
Resolve your templates using Spring’s own resource resolution mechanisms.
If you use Spring Boot, you can just use the spring-boot-starter-thymeleaf dependency. It already contains the above two dependencies as well as some others.

Spring MVC vs Java EE

So I'm about to learn Spring MVC. But what I don't understand is why should I use Spring MVC if I can implement the MVC pattern using a single servlet conroller and JSPs? What advantages does Spring MVC provide over simple java MVC pattern?
Actually yes, you can do it. Question is if you should do it. Spring MVC gives you better organization of your code.
Pure MVC Frameworks like Spring MVC are obsolete today. When combined with templating engines like Thymeleaf, it lacks functionality and developers usually reinvent JSF. For single-page apps based on some popular JS frameworks that need REST backend, JAX-RS is way cleaner and better than Spring MVC REST.
So no, today you don't need Spring MVC and can stick with pure Java EE. For simple, toy-like applications where servlets are enough, you don't really need it but it may be better to use it. For anything serious, MVC is outdated and Spring has nothing to offer.
Edit 2017: Spring offers JAX-RS integration. However, it has several pitfalls, for example Spring won't automatically register classes annotated with #Path for you. Details can be found in Dzone Article
The best way to realize that it's better to play with these technologies for yourself, if you want to try spring MVC I recommend you start with spring boot because you can create projects with more agility without configuring xml files
Spring Boot
Some Features
Create stand-alone Spring applications
Embed Tomcat, Jetty or Undertow directly (no need to deploy WAR files)
Provide opinionated 'starter' POMs to simplify your Maven configuration
Automatically configure Spring whenever possible
Provide production-ready features such as metrics, health checks and
externalized configuration
Absolutely no code generation and no requirement for XML configuration
One of the ideas applied in Spring (not invented by Spring) is
Do not reinvent a wheel.
Having a single controller is not a good idea I'd say - breaking separation of concerns principle.
You can learn more about MVC from Spring documentation.

Security configuration without XML with custom filters?

I'm using Spring Boot in STS to build a simple REST API.
I have some basic security requirements, similar to the ones described in the original post here: RESTful Authentication via Spring
The accepted answer above seems like a valid solution but does not translate to Spring Boot due to the lack of XML configuration.
How would I configure my Spring Boot application in the same manner?
You can use the same code as in that post if you want (are you sure that's what you want?) with #Configuration. The HttpSecurity builder has methods addFilter(), addFilterBefore(), addFilterAfter(), so you use those instead of the <custom-filter/> element in XML. Most (if not all) XML elements translate pretty directly into Java config.

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