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The connection between Spring, AngularJS and Maven

I am starting a new job this fall, and I need to learn a bit about Maven, Spring and Angular before I start. I am fresh out of studies, and I have never used or heard about these tools before. I have read a bit about all three, but feel none the wiser.
Could someone give an easy explanation on what these three are used for, and what the connection between them are? I guess that there must be one since I have been asked to learn all three. Also, from what I could understand Angular use HTML and CSS, is this something I should learn before using Angular?

Spring is an enterprise JVM framework, which offers things like dependency injection, aspect-oriented programming, and offers a premier MVC model. It is primarily written in Java, with a notable exception being the JSP files - those are written typically with JSTL.
Apache Maven is a dependency management and build management tool, which has the capabilities of running a project's test suite in addition to building and producing JARs or deployable WARs for releases.
Angular is a JavaScript framework which can be used to control what is rendered on the screen, and also affect presentation.
There's a lot about these to take in, and I wouldn't expect a weekend to do it for you. However, the general approach to these projects is to think about them in layers.
Given that concept...
Spring is the backend layer; it is handling much of the heavy lift with regard to the business logic and processing of data
Angular is the frontend layer; it handles interaction with the user
Maven is divorced from both layers yet can play a role in both (depending on how it's set up); it governs how the project is built and what resultant artifacts are made to be published to production

AngularJS is a JavaScript framework, the aim is to work with HTML pages and CSS. Pure HTML pages produces static web pages, the CSS is used to bring some style (colors, positioning...) to the web page with that pure HTML code, then AngularJS puts some life to the page, turning that static page in a dynamic web page, that makes possible change the content of the page dynamically etc.
So if you want to learn about AngularJS you'll need to learn at least HTML.
Spring is a Java Framework, which has the role of backend to web applications. He gets the data from the frontend (AngularJS + HTML and CSS) and does something nice with that, most commonly he processes the data and puts on a database, for instance.
Maven brings a project's structure to life (thanks to Broser's comment). He manages the dependencies of all the things you want to use on your project, useful for the build process too. Maven does a lot of things related to dependencies and packaging. So Maven can help you on the dependencies of Spring Framework, for instance.
Further information about this technologies, you can find in the official page of each of them.
Helpful links:
HTML: w3schools.com/html/default.asp
CSS: w3schools.com/css/default.asp and
w3schools.com/bootstrap/default.asp (nice to learn)
JavaScript: www.w3schools.com/js/default.asp
AngularJS: docs.angularjs.org/misc/started
Maven:
https://maven.apache.org/guides/getting-started/maven-in-five-minutes.html
Spring:
http://docs.spring.io/spring/docs/current/spring-framework-reference/html/overview-getting-started-with-spring.html
From JavaScript contents I recommend you to search for at least one good book for each one.

What are the prerequisite for Spring Roo

I have got my hands dirty in Spring Roo, I have managed to do the persistence set up for Oracle Database. Although I have gone through the Roo documentation
but it not enough for me to understand the working of this framework.
I'm not aware of Spring-MVC ,Spring-Web Flow and AspectJ rather I have knowledge of frameworks such Struts, Tapestry and GWT. Could this be a hindrances in learning Spring Roo.
Please advice as I'm running out of patience of hacking the generated code by Spring Roo. Is it good idea for me to jump in a Spring Roo project?

The Spring Roo is more than a code generator. If you make changes in your Entities, it will change the codes automatically. More like a stateful code generator. First you need to find out the commands available in Spring Roo to configure a project.
You can configure which database you want to use, which orm you want to use, whether you want to use unit-tests or which view technology you want to use. Give the commands and Roo takes care of it. You don't need to worry about which libraries to download, how to make pom file for Maven.
The configurations you got using Spring Roo is quite a standard one. I used it in the previous projects. The code generated is not optimal, for example , you can use generic daos instead of Roo generated DAO if you consider the generated codes are verbose.
Another example says, in Flex, you can use Roo to generate configurations for the communication between Flex client and J2EE server. For my case, I use parsley and observer patterns for flex client instead of the codes generated by Spring Roo. But by looking at the codes what the Roo-Flex team wrote taught me quite a lot of things too. The same things goes for GWT and Spring MVC.
So what am I saying is that as the programmers, we need not only to code we also need to read what the other wrote too . I strongly believe that it is a good way to learn and share best practices. You might get some boilerpate codes, but if you know how to apply design patterns or can enhance on them, those codes will become the gems.
Learning curve ? Not at all. The commands are as simple as DOS commands.

Spring ROO is just a command line interface for generating a lot of the boiler plate code you usually need to write to get things done in java projects.
If you want to add GWT into your project, just type "gwt setup" after you've created your models and you have full-on GWT support in your project.
The default view being generated in Roo uses Apache tiles, similar to Struts, Tapestry and JSF.
If you want to use web flow, just type in "web flow" and it'll be integrated for you, for struts support, you'll need a plugin, I've seen a couple of them floating around the web, haven't tested any of them; same goes for tapestry, you can either use a tapestry plugin or do the integration by hand.
AspectJ in the context of Roo generated scaffold is used to hide all the boilerplate code that makes code look like spaghetti, you can move code out of the aspectJ generated files into your own java files and modify them if you need to.
As for the hacking, it takes a lot of patience and time to fully understand where you should change stuff and where you shouldn't, all I can say is, happy hacking :-)

springroo is based on many technologies, but all what springroo does is to help you to generate scaffolding code using lots of addons you can install
at least it's my view of this framework after three days of learning it

what are the fastest java tools to generate CRUD screens from a DB schema?

I am constantly in search of better and faster java tools to prototype webapps. I generally start with a good data model on the backend, and work towards the screens. What are some good tools that I might not know about that can be used to quickly generate functioning CRUD screens.

Look into the following:
Grails
Play!
Roo

With Grails you can get some CRUD screens in on the order of minutes with the framework's scaffolding machinery. Its not strictly Java, but Grails can interact with existing Java code (in fact is uses Hibernate/Spring under the hood), and it will generate .war files for you to deploy in your favorite container.

Telosys Tools is probably a response
It's an Eclipse plugin for scaffolding from an existing database
The templates can be customized if necessary
Let's have a look : https://sites.google.com/site/telosystools/
There are some stacks ready to use (Spring MVC, JPA, AngularJS, Spring Data, ... )
The tutorials are here : https://sites.google.com/site/telosystutorial/

The Play Framework can generate some quick CRUD:
http://www.playframework.org/documentation/1.1RC3/guide7

Considering moving from Java/Spring MVC to Grails

I'm currently using Java & Spring (MVC) to create a webapp, and I'm considering moving to Grails. I'd appreciate feedback/insight on the following:
I have multiple application contexts in the current Java/Spring webapp that I load through the web.xml ContextLoaderListener; is it possible to have multiple application contexts in Grails? If, yes, how?
This webapp extensively uses a CXF restful web service and the current Java/Spring webapp uses the bundled CXF HTTP client. Can I continue to use the (Java) CXF HTTP Client in Grails?
I implemented Spring Security using a custom implementation of UserDetails and UserDetailsService, can I re-use these implementations in Grails "as is" or must I re-implement them?
There is an instance where I've relied on Spring's jdbc template (rather than the available ORM) and an additional data source I defined in app context, can I re-use this in Grails?
I plan on using Maven as the project management tool; are there any issues of using Maven with Grails where there is a combination of groovy and java?
Edit:
I'm considering moving to Grails to make the development of the web component of the webapp "faster," a la Ruby-on-Rails. Also, I'm considering Grails rather than say Ruby-on-Rails, because I want to continue to use the JVM and I've dabbled with Grails in the past and it was fairly easy to pick-up and use.

Probably. Grails uses a sub-class of Spring's ContextLoaderListener class which it configures in the web.xml file. I can answer more precisely if you let me know how you do it with Spring MVC.
Yes. You might even be interested in the CXF plugin, although I can't vouch for it:
http://grails.org/plugin/cxf
You should be able to use them as-is. However, you might want to check whether this is easily done with the Spring Security plugin. I believe it is, but you'll be able to get a definitive answer from Burt Beckwith, the author of the plugin.
Yes. You can also get hold of the Hibernate session factory to do raw Hibernate stuff. GORM can also work with multiple data sources:
http://grails.org/plugin/datasources
Another Burt Beckwith one :)
It depends on what you mean by "a combination of Groovy and Java". You can build Grails projects with Maven, but the integration isn't entirely smooth. If you have Java and Groovy in your Grails project, then that's taken care of automatically.
In response to Bozho, I use standard Grails services + GORM and wouldn't do it any other way. Note that if you use Java for services and the domain model, you won't have automatic reloading of services. You also lose the benefits of expressiveness and conciseness that Groovy bring.
If you want, you can use static types in Grails services to make it easier for your IDE to provide code completion. It can also give you hints on properties and methods it doesn't recognise (which would corresponding to Java compilation errors). That said, even if you use static types, Groovy can't do type checks at compilation time. You'll only find out about them at runtime.

You can do all these things in grails. It supports all existing Java classes and spring configurations (grails is built ontop of spring mvc)
However, I really wouldn't recommend moving the whole application to grails. You can perhaps move only the web layer, if you have web developers that are not java experts.
The service layer, the data access, etc, better remain pure Java. That is, only your web controllers - the components that gather the user input, handle http requests and sessions, should use grails. The rest - the stateless service classes and your domain model would better be Java. That's my opinion, but I have already some experience with grails, and static typing in the service layer will save you much trouble.

2) Yes you can use CXF as is. There is a nice layer on top of CXF called GroovyWS. I have only used it for consuming SOAP services, but maybe it has something for REST as well. It's really easy to use.
For consuming REST services I have used HTTP Builder
4) Yes. You can continue to use e.g. spring config for configuring the datasource, or any other way you do it today. Multiple datasources is no problem.
5) I have recently tried using Grails (1.2.1) with Maven. It works, but there has been some issues with both Maven and Grails trying to do dependency management. The documentation is maybe the worst part. I haven't tried upgrading to 1.3 yet because of some major Maven-related JIRAs, but 1.3.2 is right around the corner, and those issues have now been resolved :) There will also be a 1.3.2 maven archetype. Looking forward to that. "Deployment and resolution of plugins from Maven repositories" is one of the new features of Grails 1.3, so things are probably better. Roadmap for 1.3.2 says release today, but there are 8 issues left at time speaking, so my guess would be tomorrow, the Grails releases are usually on time. If you can wait for that, you will probably save yourself some trouble.

If you are looking for rapid application development but aren't otherwise particularly enthused about groovy, you should look into spring-roo. It offers the same kind of RAD functionality, but builds a completely standard java + ORM + spring-mvc app (which has no actual dependencies (runtime or compile) on roo). It's definitely not as mature as grails, but you may find that it better suits your existing experience with statically typed java code and existing ORM, etc. I've only done a couple of small pet projects in roo, but I've been very impressed so far, particularly with how easy it is to customize the generated code and move back and forth between written and generated code. The initial tutorial is very rapid and quite revealing.

appfuse vs roo - what would you use

Appfuse vs. Roo, what would you use and why?
What are the sweet spots of each.

As per the answer I gave to TheServerSide thread on this issue...:
AppFuse aims to provide a single initial scaffold of your new project. This is similar to Maven archetypes or Eclipse's "new project" features in that you run them once at the start of a new project and then you maintain the scaffolded code going forward. The scaffold system has no further involvement in your project once you've run it once.
Roo, on the other hand, provides a round-trip aware active code generator for your long-term usage on a given project. As such Roo offers value both at initial creation time as well as whenever you are modifying the project going forward.
In practical terms this means as you evolve your project, Roo will automatically maintain certain files. To take a simple example, when you add (or remove) a field, Roo will update the toString, getters/setters, JSP pages etc for you automatically. It also offers commands so you can add new capabilities later. So if you need to add security six months after you created the project, you just "security setup". Or if you need to send emails, you just "http://static.springsource.org/spring-roo/reference/html/command-index.html#command-index-email-sender-setup". There are similar commands for many other capability areas well, such as Spring Web Flow, JUnit, Selenium, common JPA providers etc. You just defer the decision as long as you like, and Roo will only add those capabilities at the time you ask for them (and it will also automatically use those new capabilities in your project).
There are many other differences as well. Roo allows extension via user-developed add-ons, it offers a highly usable shell, it allows you to incrementally build a new project and add features only when required, it extensively supports the latest versions of the major Spring technologies, it comes with a SpringSource-developed (and therefore endorsed) application architecture and so on.
A read of the Roo Reference Guide's Introduction Chapter or simply completing the ten minute test project will illustrate they are very different in approach.

My notes on AppFuse and Roo:
AppFuse
Is a fully working template application/project.
Traditional DAO <-> Service <-> Controller architecture
Easy to get started with maven archetypes
Great documentation and tutorials
Not really up to date. Spring 3 final is soon to be released and AppFuse is based on 2.5 (?)
Spring Roo
Spring Roo on the other hand is a tool that speeds up development by using code generation.
Getting started with a new, fully configured project takes 1 minute
Creates rich domain objects where CRUD are weaved into the domain objects using AOP instead of traditional DAOs/services
Hard to grasp if you are new to Spring
Documentation is not that good yet
Really cool! I.e. add Spring Security to your project with just one line of code!

Telosys (a lightweight code generator) is also a good alternative. See
http://www.telosys.org/
It produces very clean code (without adherence like ApectJ)
and the templates are customizable
There's a stack of templates designed to generate Spring MVC web apps (and many others to generate code for other kinds of frameworks).

for me Appfuse but it is not up to date, but the spring roo using aspectj and there are parts of code you should not touch and I do not like that.

Spring Roo
Pros.
1.
Customizable : You add and remove diffrent framework and addon as per your requirement.
Database Reverse Enginnering : Create CRUD applications if you have database schema ready.
Strong Spring community support.
NOSQL MongoDB support
Can create required add-ons.
Cons :
Require in depth knowledge of Aspect oriented and Spring stack.
Require little more time to learn spring roo as compared appfuse.
Appfuse:
Pros:
Good one to start small and mid-size enterprise application with
struts, JSF and Spring
Complete open source code.
Enough documentation.
Twitter-bootstrap ready.
Cons:
Customize application but not like Spring roo.

For starters, roo looks more over engineered, with code generation, use of aspect oriented programming and more.

Appfuse doesn't seem to be maintained anymore seeming that the last version was released on May, 2008.
Roo it's right now a little bleeding edge, because of the use of the still-unreleased version 3 of Spring Framework, but that will change, and that version brings a lot of interesting changes to the table.
It also upsells you on more of the Spring technologies portfolio, such as STS and tcServer, and makes it dead easy to use Spring Security and Spring WebFlow.

I am going with ROO.
I am already using
Spring
Spring ORM/JDBC
Spring MVC
Spring Remoting
STS (Tool-suite)
So my preference is SpringSource products, AS I am already familiar with API style, documentation, conventions of SpringSource and even their coding practices once I extended/implemented security-framework's code.. ;-)
so, my advice is go with the tool/framework which is more natural to you..
Cheers,

AppFuse -> change to SpringFuse
I more prefer use SpringFuse

The question is some years old and in the meanwhile there are new productivity tools I want to point out:
Generjee. Generjee is a full-online tool. You define online your requirements and the (optional) data model. Then you get the generated code as a download.
The generated code is independent from generjee. The tool is useful for starting development projects from an integrated full-stack code base.
generjee will generate for you:
JPA code according to your data model
JSF code to create, read, edit, filter, sort and export data
user management, registration and login
your defined user roles and specific access permissions for this roles
I18N support
file upload support
Forge. To describe it in some words, it is "like Roo". But Forge is not as strong based on Spring and AspectJ as Roo.

AppFuse has integration with Tapestry, Wicket and other Web frameworks which Roo does not - yet

The AppFuse project was shut down in April 2016. Its founder, Matt Raible, recommends using JHipster as an alternative.