Develop Reference

JavaMoney and Maven dependencies

I decided to start work on a little financial calculator for personal use and figured that it would be useful to implement an external library for handling money. I decided on JavaMoney and am still figuring out how Maven and dependencies work.
I have the following code in the POM file:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>FinancialCalculator</groupId>
<artifactId>FinancialCalculator</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>pom</packaging>
<dependencies>
<dependency>
<groupId>javax.money</groupId>
<artifactId>money-api</artifactId>
<version>1.1</version>
</dependency>
<dependency>
<groupId>org.javamoney</groupId>
<artifactId>moneta</artifactId>
<version>1.4.1</version>
<type>pom</type>
</dependency>
</dependencies>
</project>
When I try and import javax.money.*;, it tells me that it cannot be resolved. I imagine I have some great misconception about how this works, so any help would be appreciated. I apologize for my ignorance.
EDIT:
I was told that I need to clean and build the project for Maven to download the appropriate JAR files. I'm using Eclipse, so I went into Project > Clean... and selected the Maven project, and I have auto-build on so it should just rebuild immediately after; but just in case, I also cleaned and manually built the project. I still can't import the javax.money package, even after cleaning and building a few times. Any help is much appreciated.

You need to check if you are importing the correct package. GroupId and package name do not always coincide. Look into the docs of the projects to figure out what you need.
Use Run As -> Maven Build ... to run the command clean verify. Look into the command line output what errors occur. These are much more reliable than those of Eclipse.
If you cannot download anything, then you have probably a problem with your network or firewall.
If Maven plugins can be downloaded, but your dependencies are not downloaded, you may have a typo in the name or version.
You may have also a syntax error in your code, but Maven will tell you this.

Attempting to install a java library for the Botometer API, but the Github page doesn't have a lib folder or a centralized Jar file [duplicate]

I don't know how to use Maven at all. I've been developing for a couple years with Eclipse and haven't yet needed to know about it. However, now I'm looking at some docs that suggest I do the following:
"To include it within your project, just add this maven dependency to your build."
<repository>
<id>jboss</id>
<url>http://repository.jboss.org/maven2</url>
</repository>
...
<dependency>
<groupId>org.jboss.resteasy</groupId>
<artifactId>resteasy-jackson-provider</artifactId>
<version>1.1.GA</version>
</dependency>
How do I do this with my Eclipse project?
Please assume I know nothing about Maven. I just figured out it might be installed on my computer by typing mvn on the command line, but that's seriously the extent of my knowledge. I would be happy to continue knowing nothing about Maven if there is an equivalent, non-Maven way of following these instructions with Eclipse.

On the top menu bar, open Window -> Show View -> Other
In the Show View window, open Maven -> Maven Repositories
In the window that appears, right-click on Global Repositories and select Go Into
Right-click on "central (http://repo.maven.apache.org/maven2)" and select "Rebuild Index"
Note that it will take very long to complete the download!!!
Once indexing is complete, Right-click on the project -> Maven -> Add Dependency and start typing the name of the project you want to import (such as "hibernate").
The search results will auto-fill in the "Search Results" box below.

In fact when you open the pom.xml, you should see 5 tabs in the bottom. Click the pom.xml, and you can type whatever dependencies you want.

You need to be using a Maven plugin for Eclipse in order to do this properly. The m2e plugin is built into the latest version of Eclipse, and does a decent if not perfect job of integrating Maven into the IDE. You will want to create your project as a 'Maven Project'. Alternatively you can import an existing Maven POM into your workspace to automatically create projects. Once you have your Maven project in the IDE, simply open up the POM and add your dependency to it.
Now, if you do not have a Maven plugin for Eclipse, you will need to get the jar(s) for the dependency in question and manually add them as classpath references to your project. This could get unpleasant as you will need not just the top level JAR, but all its dependencies as well.
Basically, I recommend you get a decent Maven plugin for Eclipse and let it handle the dependency management for you.

Open the pom.xml file.
under the project tag add <dependencies> as another tag, and google for the Maven dependencies. I used this to search.
So after getting the dependency create another tag dependency inside <dependencies> tag.
So ultimately it will look something like this.
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>doc-examples</groupId>
<artifactId>lambda-java-example</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>lambda-java-example</name>
<dependencies>
<!-- https://mvnrepository.com/artifact/com.amazonaws/aws-lambda-java-core -->
<dependency>
<groupId>com.amazonaws</groupId>
<artifactId>aws-lambda-java-core</artifactId>
<version>1.0.0</version>
</dependency>
</dependencies>
</project>
Hope it helps.

I have faced the similar issue and fixed by copying the missing Jar files in to .M2 Path,
For example: if you see the error message as Missing artifact tws:axis-client:jar:8.7 then you have to download "axis-client-8.7.jar" file and paste the same in to below location will resolve the issue.
C:\Users\UsernameXXX.m2\repository\tws\axis-client\8.7(Paste axis-client-8.7.jar).
finally, right click on project->Maven->Update Project...Thats it.
happy coding.

I have faced same problem with maven dependencies, eg: unfortunetly your maven dependencies deleted from your buildpath,then you people get lot of exceptions,if you follow below process you can easily resolve this issue.

Unable to build JAR file for my maven PARENT prroject

I have created two training projects aiming to the creation of a Java Test Automation Framework with Selenium.
Both projects have been stored in my personal git: https://github.com/omarjmc
Framework: Contains main classes and all the code needed to execute successfuly the tests
Project: Demo project that will use the methods specified in the Framework project
Additionally i added the dependency to the Framework project in the demo Project's POM and I also created a release of the Framework project and attached the JAR file
enter image description here
Currently I have to clone both repositories and run mvn clean install on the framework to get the JAR file and change the packaging back to pom, but I want to just clone the demo project, run mvn clean install there and still get the Framework JAR file.
What am I missing the POM file?

Omar you have to create a maven multi module project for this requirement. Project will be the parent project and it should contain framework as child.
The basic code structure for pom.xml for Project should be like this.
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.project</groupId>
<artifactId>multi</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>pom</packaging>
<name>project</name>
<modules>
<module>framework</module>
</modules>
</project>
You can refer below the github project for this exact requirement.
https://github.com/jamesward/maven-multi-module-example

I created a multi-module proyect, but it only works if you download the original repository, what I want is to have them in separate repositories and just download, and use, the project child

Easily add libraries to Eclipse Java Oxygen

I know there are post about JAVA libraries in Eclipse and I used a way to add some .jar files (like apache.poi and jsoup) to my project. My question is:
Where do we have to put those libraries and what settings do we have to change, so to make the libraries available for every future project we start ?
Thank you!

The most common tools for bringing dependencies into a Java project are Maven, Gradle, and Ant. I'll focus on Maven, as I estimate it to be the most popular of the three (though I have come to prefer Gradle).
I'm going to assume you have the following prerequisites installed on your machine and each of the developers on your team:
JDK 1.7 or above (in other words, Java)
A Java-focused IDE like IntelliJ or Eclipse
Here's what you need to do:
You and your team members will install Maven
You will create a pom.xml for each new project.
You will specify the dependencies for the project (like jsoup) in your pom.xml
Here's what Maven will do for you:
It will download all the dependencies you specify from an online repository like https://mvnrepository.com/
It will cache the dependencies in a directory in your user home folder called .m2 so that it doesn't need to download dependencies more than once per project
It will resolve the dependencies within each of your dependencies and avoid putting the same dependency on the classpath twice
The minimum pom.xml file you need is as follows:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.yourcompany</groupId>
<artifactId>your-project</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.jsoup</groupId>
<artifactId>jsoup</artifactId>
<version>1.8.3</version>
</dependency>
</dependencies>
</project>
Copy that into a file called pom.xml in your root project directory. You can add any additional dependencies in the <dependencies> section of the XML file. By convention, all of your classes and code should go into the directory structure src/main/java/.
Any Java IDE you use will know how to open a project from a pom.xml file. In IntelliJ, you select File->New->Project from existing sources, navigate to your project's root directory, select your pom.xml, and click Open. IntelliJ will then open your project as a Maven project, read your pom.xml, and make all of your dependencies indexed and available for code completion and compilation.
Hope this helps

Get started with maven

I have experience in Ant, how to get started with maven. Any advantage with maven over ant?

There's a quite large difference, where ant forces you to create your own targets you will get a default set of targets for maven, e.g., clean, install, package etc without scripting them.
Maven promotes that you use a common directory structure for java classes, resources etc. If you do, maven is just on xml file where you specify some project metadata such as name, package and most importantly depenencies. It provides similar dependency lookup to what ivy does for ant.
Based on the standard maven promotes, it becomes very easy for developers to approach and build your projects. With an IDE such as Netbeans it's enough to select open project, and then hit the install button to compile and install the project in your local repository.
I recommend working with maven the maven way. Doing things differently will often cause more pain than it's worth. Maven offers a plugin structure where you can perform various tasks, such as invoke the ant-library should you need to. If you're actively working with multiple projects (and want project switching to be as easy as possible) maven is a huge leap forward, especially if combined with repository server such as Nexus or Archiva.
To get started
Either you can generate your project structure using the archetype goal of maven, or you could do it the way I do by copy-pasing an empty template project every time. Then you need the maven binary and the project definition file pom.xml which I typically also copy paste between projects.
A sample is included below. With this sample you'll get the external library log4j, and you automatically get all nececcities to build and package your own project (in this case to a jar file).
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.company</groupId>
<artifactId>projectname</artifactId>
<packaging>jar</packaging>
<version>0.1.0-SNAPSHOT</version>
<name>${project.artifactId}</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.16</version>
</dependency>
<!-- add more dependencies here ... -->
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.6</source>
<target>1.6</target>
</configuration>
</plugin>
</plugins>
</build>
</project>

Around two weeks ago, I was in the same situation. In my opinion, Maven is a lot more powerful as compared to Ant.
It has a generate command which makes it very easy to start new projects of various kinds (artifacts) and will also build a standard directory structure along with the pom.xml file,
thereby taking care of a lot of things that are needed to be written in the build.xml file of Ant.
Managing dependencies is also a lot better. Maven will download dependencies from repos and will store them in a central repo on your system. If a dependency is already present in the local repository, it will take it from there instead of downloading it again.
I use eclipse and maven has a command (mvn eclipse:eclipse) which creates the .classpath file in the project directory. So no need to add the libraries again in eclipse.
The Getting started guide on the maven website is a good resource and covers quite a lot of stuff -

In comparison to Ant what Maven does well is dependency management and standardisation of the build lifecycle.
As for learning a bit more about it, the Maven documentation is pretty readable and thorough.
I'd start by looking at the introductory piece that explains some of the core principles about the difference between Maven and other build tools.
http://maven.apache.org/what-is-maven.html
Then downlod and install maven, open your terminal and type...
mvn archetype:generate
Select all defaults and you'll end up with a simple build-able project with one runnable class and a matching test file. Use that as a test project to familiarise yourself with the build lifecycle and dependency resolution process.