J2EE Maven Eclipse Hello World Tutorial Part Two

Hello World Beginner Tutorial using J2EE and Maven

This is part two of J2EE application with maven continued from Part One.

If you haven’t accomplished J2EE with Maven tutorial, please first complete it by going here

Maven relies highly on the pom.xml file that we would put on the project root folder. Lets do that.

In this part of J2EE tutorial and Maven tutorial, we will proceed from creating a pom.xml file which is the heart of maven.

3 Create the pom and compile the project using maven.

3.a put the following pom file in the MavenEclipseJ2EE directory.
Continue reading J2EE Maven Eclipse Hello World Tutorial Part Two

Maven error Annotations are not supported in -source 1.3

The Error

Are you using annotations in your project?

If so, you will get this error if you try to do mvn compile or mvn install.

You may have also seen this if you are building your project on eclipse as well.

The solution

The default maven relies on JDK 1.3 for its building the project and you might be using a JDK above 1.3. Also, JDK 1.3 does not implement annotations.

The solution is to tell the maven the current non-1.3 JDK you are using on you pom.xml file.


<project>
.
.

  <build> 
    <plugins> 
      <plugin> 
        <artifactId>maven-compiler-plugin</artifactId> 
        <version>2.3.2</version> 
        <configuration> 
          <source>1.8</source> 
          <target>1.8</target> 
        </configuration> 
      </plugin> 
     </plugins> 
   </build> 
</project>

For the source and target you will provide your current JDK you are using.

Importing packages to eclipse added by maven to java web project

If eclipse is having a hard time acknowledging the packages you got through maven, here are the step by step fix for it..

1. Go to your projects root, where the pom.xml resides

2. issue mvn eclipse:clean

3. issue mvn eclipse:eclipse

4. this could be optional, on eclipse go to the project, right click on it and select build project

Using mvn for creating and running a boilerplate minimal java application

It is almost a must to use mvn or any other build tool when dealing with java.

With mvn you can start a minimal simple all included java application and you run that too.. Just follow this. I will assume you are on linux or mac environment for this and also I am assuming you already have maven installed
Create a new folder and say mavenrocks

mkdir mavenrocks

Then add the following

mvn archetype:generate

What it does is, it will use a plugin to create a boilerplate application that holds basic src files along with standard directory structure.
if you do the listing on the created folder you will see:

.
./pom.xml
./src
./src/main
./src/main/java
./src/main/java/com
./src/main/java/com/gullele
./src/main/java/com/gullele/App.java
./src/test
./src/test/java
./src/test/java/com
./src/test/java/com/gullele
./src/test/java/com/gullele/AppTest.java
./target
./target/classes
./target/classes/com
./target/classes/com/gullele
./target/classes/com/gullele/App.class
./target/maven-status
./target/maven-status/maven-compiler-plugin
./target/maven-status/maven-compiler-plugin/compile
./target/maven-status/maven-compiler-plugin/compile/default-compile
./target/maven-status/maven-compiler-plugin/compile/default-compile/createdFiles.lst
./target/maven-status/maven-compiler-plugin/compile/default-compile/inputFiles.lst

and to run it

mvn execute:java -Dexec.mainClass="com.gullele.App"

Maven J2EE Eclipse: Hello world in J2EE and Maven on Eclipse

Step by step tutorial on J2EE and Maven on IDE Eclipse

Here is a simple yet basic tutorial for a J2EE application using maven and Eclipse from the scratch showing you step by step.

This tutorial assumes you know the basics of Maven and J2EE. This is just a step by step tutorial to show the marriage of the two.

Also, it is assumed that you have installed maven and tomcat on your machine which are fairly easy to do with simple googling.

Lets Start

1. Create simple Hello world module on Eclipse
1.a Open Eclipse Go to file->new->Dynamic Web Project
1.b Name the project as MavenEclipseJ2EE and hit Finish

We have finished the first step.

Now, maven expects some kind of folder structure. Well, you can do it in your own way and make extra configuration, or you can accept what is accepted as standard and have fun.. I go with the standard maven directory structure.

Here is the maven structure


src/main/java
src/main/resource
src/main/webapp

These are going to the source folders. So lets create them.

2. Creating source folders that are acceptable by maven

2.a Go to terminal or how ever you would create folders and create the folders as:

MavenEclipseJ2EE/src$ mkdir main
MavenEclipseJ2EE/src$ mkdir main/java
MavenEclipseJ2EE/src$ mkdir main/resources
MavenEclipseJ2EE/src$ mkdir main/webapp

2.b Go back to Eclipse, select the project and hit F5 or right click on Project and hit refresh. You will see the newly created folders under src

2.c Right click on the project, select properties, select build path and hit source tab

2.d You would see the previous source folder there. Select it and hit remove to remove it. We do this since we are changing the source folders

2.e Then hit the button add folder, expand src, expand main and select the java, resources and webapps only. Hit OK and hit OK again to finish creating source files.

Cool, so our folder structure is ready for Maven. Now lets move to the maven itself.

Maven relies highly on the pom.xml file that we would put on the project root folder. Lets do that.

Continue to part two