Eclipse Maven project to Dynamic Web Project layout - java

I am used to the layout provided by the Dynamic Web project in eclipse where you have all your Java code under the src folder, your JSP files, etc under the WebContent folder and the WEB-INF resides right under the WebContent folder. Also, the Output folder is hidden from the project tree. Maven has its own format which I find somewhat confusing, it creates its now target folder and source/main/java folder and some test folder under target...
Is there a way to create a Maven project and have it use the Dynamic Web project project tree layout?
I tried changing the Deployment Assembly entries to match that of the Dynamic web project and have also update the Java Build Path src and output to match the Dynamic Web project one but I get strange, cryptic unfriendly errors when I do a Run/Install. Can you provide me with details on how to go about doing this cleanly?

What you need to get used to using is the concept of archetypes in Maven.
The concept is like project templates ready for you to use that are automatically understood by Maven.
mvn archetype:generate
will get you an interactive listing of all the available archetypes
What you want to look for is maven-archetype-webapp this will give you a basic skeleton framework of what Maven is expecting a webapp to look like.
There are others that include support for different frameworks and what not.
mvn archetype:generate | grep webapp
will filter out all the choices that are webapp archetypes
Then it is a simple mvn clean package and you get an exploded dir and a .war in the target directory, you can even enable the Tomcat plugin to automatically deploy to Tomcat. Other J2EE servers are supported as well.
Then you use the Maven plugin for eclipse to load the project based on the pom.xml file.
You could create your own non standard layout and get it working by manually configuring everything thing and create an archetype out of it but that kind of defeats the purpose of a single way of doing things with a tool like Maven.

Using m2e 1.3+ and m2e-wtp 0.16.0+, you can just :
create a new Dynamic Web project
right-click on the project > Configure > Convert to Maven...
Fill in the Maven coordinates of your project and finish
It'll mavenize your project, keeping the standard Eclipse project layout.
See http://wiki.eclipse.org/M2E-WTP/New_and_Noteworthy/0.16#New_project_conversion_participants for more information

Related

Does creating a folder in default maven directory structure offered by eclipse lead to any issues?

I've recently started learning Spring REST. As part of my learning process, I developed a simple Hello World application using Maven. The directory structure of maven offered by Eclipse doesn't contain the "
java" folder in src/main. So, I added it explicitly. It turns out the application gives me a 404 error as you can see in the below image. I'm sure this has something to do with the class path. As I'm new to maven I don't understand the concept of the classpath.
But in the second image, I created the project using "co.ntier" (maven archetype for Spring MVC). The directory structure of this archetype has got the java folder which is why when I run the application I'm able to get the output.
How to add or configure maven so that every time I create a new maven project, the directory structure will have the java folder? Please help me.
I recommend to always create a Maven project from an archetype.
You can e.g. use the quickstart archetype for a simple project.
The presence of a "java" folder has nothing to do with whether an application can successfully serve something at a particular url. They are not directly related. This also has nothing to do with the classpath.
However, the red mark on the project indicates an error, and as the DEFAULT location for compilable source in a Maven project is "src/main/java", it seems clear that the lack of the "java" folder results in the project not being deployed, which IS why you get a 404.
In short, if you have red marks in the project, it's not going to deploy.

How to create a Java Spring WebApp Folder Structure using Gradle

I am making a Java Web App project using Gradle. Now, for building a Gradle web app plenty of resources are available over the net.
But, my issue is a bit different. Suppose, I want to initiate a Gradle based project and make a web app suitable project folder structure just like we do in maven. Is there any specific way to create so in Gradle. I have found something about templates. Is there any way to do it or do I have to create a folder structure manually and then attach to Gradle so that it can build a war out it properly.
You can use maven to create the project and then create gradle build from it:
mvn archetype:generate -DgroupId=com.example -DartifactId=java-web-project -DarchetypeArtifactId=maven-archetype-webapp -DinteractiveMode=false
Then:
gradle init --type pom
You didn't mention your IDE, but I will answer for IntelliJ IDEA and for Eclipse the steps are similar.
Go to File --> New --> Project, choose Gradle from the left menu and choose both Java and Web options (see image below).

what is the difference between maven-archetype-webapp and eclipse dynamic web project

why do I need to apply: mvn eclipse:eclipse command?
are they equivalent to application container/server?
Is there a file for which customizing is necessary besides web.xml?
when you create a web project using maven, like maven-archetype-webapp. It creates the folder structure as recommend by Maven for a webapp like shown here .
Now when you try to import these folders in Eclipse, it still would look like folders but eclipse cannot understand the nature of these folders. Eclipse relates folders and contents within them to an Eclipse dynamic web project only through its .project , .settings files
So in order for your maven project to be understood by Eclipse, you run the goal mvn eclipse:eclipse. After executing this goal, maven generates the .project, .settings files necessary for eclipse to understand the project as Web project.
This is however optional. You can still import the project as Maven projects within eclipse and continue to use them but you cant rely on Eclipse's features like clean/ build / build automatically.
Though I use eclipse, I dont rely on Eclipse's build feature. I have installed Maven eclipse plugin and that allows me to run maven goals and commands within Eclipse which is as good as running Eclipse's build feature. Hope this helps.

Merging JSP code and Maven code

I have an Apache Maven Project for JIRA REST API. Now I am creating a JSP project to send some data to java file in my Maven Project. I want to know how can I merge them in single project. Maven Project has a pom.xml file and the java file for Maven are located in src/main/java whereas for JSP it is in different folder. (Java Resources/src)
Can anyone please tell what folder should I copy and merge?
EDIT: Found the answer. Right click the Maven project and go to Project Facets and check Dynamic Web Module option.
you can create a Maven Webapp using following archetype
-DarchetypeArtifactId=maven-archetype-webapp
which will automatically creates the desired folder structure
in your case its apart from src\main\java
src\main\resources
src\main\webapp
src\main\webapp\WEB-INF --THIS IS WHERE JSP's will go
Standard Maven Directory Layouts
Maven Web Application
Found the answer. Right click the Maven project and go to Project Facets and check Dynamic Web Module option.

Java Dynamic Web project with Maven and Eclipse

I have several questions about creating a Java Web application with Maven and Eclipse:
How do I create a Java web project with servlets, jsp, and other classes with Maven?
It creates a simple directory structure, src->main->java. Where and how do I put the web-inf folder?
Do I need to add the jdbc-drivers manually to the folder inside the web-inf/lib, or is it ok just to point out the dependency?
Is there a way to test the servlets with junit?
Wow that's a lot of questions at once. I admit that setting up a webapp project with Maven and Eclipse can be tricky, so I'll try to answer them all.
Creating a Web application project with Maven
How do I create a java web project with servlets jsp and other classes with maven? It creates a simple directory structure, src->main->java.
When you are creating a Java web project, the final product should be a WAR or EAR file. WAR and EAR files are JAR files with a specific structure that can be deployed in an application server or servlet container.
As mentioned, the easiest way to set up a Maven project for web applications is to use archetypes:
mvn archetype:generate -DarchetypeArtifactId=maven-archetype-webapp
If we create a project with this archetype then a simple directory structure and pom.xml are generated. This project follows the standard Maven directory layout you mention, with /src/main/java/, /src/test/java, etc. Maven generates the WAR file from this structure with the war:war goal.
Note that this archetype is for a very simple (outdated) web application, but it's the best available starting point. You probably want to discard the web.xml file and create a new one that supports Servlet 3.0.
WEB-INF location
Where and how do I put the web-inf folder?
By default, Maven expects resources that should go in the root of the WAR file -- such as images, html pages and the WEB-INF directory -- to reside in /src/main/webapp/. So the WEB-INF folder should be located at /src/main/webapp/WEB-INF/. If you use the maven-archetype-webapp this directory is automatically created, along with a sample web.xml file.
Eclipse integration
You mentioned Eclipse in the question title, and it is indeed possible to develop Mavenized web applications in Eclipse with the m2eclipse plugin. Eclipse has good support for Web applications through WTP (Web Tools Platform).
Although many guides on the internet (wrongly) recommend it, you should not use the mvn eclipse:eclipse command to create the Eclipse project. This plugin can only generate WTP projects for very old Eclipse versions (WTP 2.0 is the maximum). Instead, use the m2eclipse plugin as described here.
Dependencies
Do I need to add the jdbc-drivers manually to the folder inside the web-inf/lib, or is it ok just to point out the dependency?
There is no need to do this manually, since one of the key strengths of Maven is dependency management. If you add a dependency in the pom.xml with a scope of compile or runtime, the JAR file will be automatically included in the WEB-INF/lib/ directory of the WAR file. For example to add the Postgresql JDBC driver dependency, add this to your pom.xml:
<dependency>
<groupId>postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>9.1-901.jdbc4</version>
</dependency>
Since the scope is unspecified Maven will assume it is in the the default scope compile. The result is that Maven will include WEB-INF/lib/postgresql-9.1-901.jdbc4.jar in the WAR file.
Testing
Is there a way to test the servlets with junit?
This question has been asked (and answered) on Stackoverflow:
Unit testing a Java servlet
Unit testing servlets
References
Hello World with JSF 2.0, Glassfish 3, Maven, SVN and Eclipse.
You should create a project based on the webapp Maven archetype, not the default one you're using.
I'm using SpringSource Tool Suite, which, for this exercise, is the same as Eclipse with m2e. Create a new Maven project and make sure you select the following archetype:
The Maven the command-line way of doing this is:
mvn archetype:generate -DgroupId=com.mycompany.app -DartifactId=my-webapp -DarchetypeArtifactId=maven-archetype-webapp
This archetype will put the WEB-INF folder in the correct location (under src/main/webapp).
You can find more information at http://maven.apache.org/guides/mini/guide-webapp.html
Just create a normal "Dynamic Web Project". Then right click the project name and select Configure > Convert To Maven Project. It can take up to a minute to complete the conversion, so be patient. See the following article:
http://aykutakin.wordpress.com/2013/12/04/create-eclipse-dynamic-web-project-with-maven-2/
If that doesn't work, try this:
http://crunchify.com/how-to-create-dynamic-web-project-using-maven-in-eclipse/
Step 1: create your web app folder.
Step 2: Move to that folder in command prompt.
Step 3: use following command:
mvn archetype:generate -DgroupId=com.helloworld -DartifactId=HelloWorldDemo -DarchetypeArtifactId=maven-archetype-webapp -DinteractiveMode=false
DarchetypeArtifactId=maven-archetype-webapp will create a maven web project.
Step 4: Now on command prompt go inside the project folder and use this command:
mvn eclipse:eclipse -Dwtpversion=2.0 to make your project a dynamic web project for eclipse, now import this newly created project as an "Ëxisting project"
Use m2eclipse plugin of eclipse to enable MAVEN in eclipe.
Web.xml will be at \src\main\webapp\WEB-INF

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