I have a question please,when using opencv in a Maven project,do I need to install opencv in my computer ?
I've added the dependency in pom.xml and the dependency was added but when running the code it said no opencv in java.library.path. It needs to specify the dll path
Thanks for your help.
"When using opencv in a Maven project, do I need to install opencv in
my computer?"
Yes, you do.
When adding dependencies you are telling the compiler where to find the library you want to use. You may not need the library to be accessible from your computer, but the files definitely need to be accessible from your project directory.
Links that may help:
Maven: Introduction to the Dependency Mechanism
Understanding Dependencies
Related
Since version 2.2.0 Tycho has introduced a new feature to allow using maven artifacts in PDE target platforms, and here's the how-to. Following its instructions I have included an artifact of Saxon-HE into my target platform. I can see the wrapped OSGi bundle of Saxon after ticking the Show Location Content option in the Target Definition Editor. Also I ran mvn clean verify command to make sure that the artifact is downloaded into my computer. However,
as I began to try to import the package into my Eclipse plugin code, I found no suggestions from this package.
When I tried to include the package as a feature in the Product Editor, I couldn't find any option.
In addition, when attempting to include it as required plugin / imported packages in the Plugin Editor, there was no option, too.
What's more, the product produced by mvn clean verify did not contain such plugin as Saxon-HE after checking my whole RCP project.
All the efforts in vain above made me wonder how I can use a maven artifact in my plugin development. I desperately need the functionalities Saxon-HE provides with to enhance my plugin. Anyone experienced sharing your expertise?
-- 2021.08.13 update --
Manually I included this plugin in the plugin list of my RCP project via source file editing. Its jar file appeared in the plugin folder of the product. But anyway I was not able to validate the availability of the library in the dependency tab of the plugin manifest editor as shown in Vogella's tutorial. Restarting the IDE did not help, either. This might mean that I have to manually code the source code without the content assistance.
I am a total beginner at maven, I have read about it online but I am still confused how it can be used. I have eclipse Oxygen version installed and when I open projects I can see maven project option is already there. I was even able to create a maven project using YouTube tutorial. But now then I saw popular plugin called m2eclipse but I am not able to comprehend why is it actually used; when my application ran without it.
I am learning maven to get started with spring boot but I am finding it really overwhelming where to begin with, and many of the tutorial sites state to download maven (But maven already comes along with eclipse?)
Please explain.
Apache Maven is a build tool - a tool for compiling the source code of a project into a program that you can run (for example a jar file, or a war file that can be deployed on a Java EE application server). Besides automating all the tasks for building a project, it also gives you a standard way to organize your project and to keep track of dependencies (libraries that your project needs).
Why do you need such a tool?
When you write a small program that consists of one, or maybe a few source files, it's easy enough to compile it by hand on the command line, by directly using the Java compiler javac that comes with the JDK.
But when your project becomes more complex, and you have hundreds or even thousands of source files in multiple modules, it becomes really hard to keep track of everything and cumbersome to compile the files using javac. If your program needs libraries, it becomes even more complex, because you have to make sure that all the libraries are on the classpath, and some libraries need other libraries, which also have to be on the classpath.
A tool such as Maven helps you to compile all the source files in the right order and to keep track of all the libraries. Maven can automatically download libraries from the web and add them to your project, and downloading everything and building the whole project can be done with one simple command such as mvn clean package.
Spring Boot is part of the Spring Framework, which is a huge framework with tons of useful functionality for developing projects in Java. A Spring Boot project typically needs dozens of libraries, and it would be very hard to use if you'd have to keep track of all those libraries by hand - so that's why it uses Maven to manage all of this for you.
A Maven project is configured using a file named pom.xml - in that file, you describe your project and you put a list of libraries that your project needs. When you build your project, Maven will read the pom.xml file and figure out automatically what source files need to be compiled, and what libraries need to be downloaded.
m2eclipse comes preinstalled in Eclipse (at least when selecting "Eclipse for Java developers" or "Eclipse for Java EE developer"), thats why you were able to use Maven by default.
Still you probably want a command line Maven, because that's most likely how it will eventually run on the CI server, sometimes Eclipse Maven installation can produce different result than the command line install.
I am using the hector & astyanax projects. These projects used to require maven, and now astyanax requires gradle.
I would like to statically link one of these projects to my java project (which is not built using maven/gradle). I am not interested in updating the version of astyanax every time they make a new release. I am not interested in mavenizing/gradelizing my own project.
So, two problems arise: 1. Getting the astyanax jars. 2. Getting the depenedency Jars.
At first, not having time to thoroughly understand maven (get off my lawn!), I copied all of the jar files in my global .maven directory into my project, and linked to them. Problem is, it's a pretty messy solution.
Is there an easier way to get all jars needed to use a gradle/maven library? (While I don't mind using gradle to build astyanax, I don't want to use it to build my own project).
Getting jars for distribution, seems like a very basic use case, am I missing a simple way here?
astyanax is published to maven central as com.netflix.astyanax:astyanax:1.56.42. Any build tool (Grails, Maven, Gradle, Buildr, SBT) that resolves from Maven can make a dependency on Astyanax and have its dependencies transitively downloaded. That fact that it's built with Gradle doesn't change how it's consumed.
From your question, it's unclear how you want to resolve these libraries. If you don't want to use a tool (Grails, Maven, Gradle, Buildr, SBT), then you'll have to manually navigate every dependencies and its dependencies from Maven Central. It's quite uncommon for a modern java project to manually download dependencies anymore, the practicalness given the complex dependencies graph make it prohibitive.
In our application, we're going to package the JRE as an embedded DLL (to avoid typical Windows issue).
As our project is a typical Maven citizen, I would like to include that JRE as a Maven dependency, to use it later. But is there such an artifact available? And if not, what could be the preferred way to package it?
zipping the whole JRE folder and uploading it to our Nexus?
use a "magical" artifact?
any other solution?
I think this was already touched here
Also if you are on Linux, then you can use RPM solution for application/server, but it is the solution more for deployment and not development.
I have many projects that use a bunch of exact same class.
Is there a way to add a script to Xcode, so, each time i compile, he go to a network folder and update is files from there... If newer. (i do this step manually, but could be great to automate it)
Thanks
You could add a "run script" build phase to copy over files before compiling if that's really what you want to do. That would catch updates for you but I don't think it would help you if new files are added (though copying them into a location your project has a folder reference rather than a group pointing to might work).
That said I think there's a better solution. It sounds like you're reinventing a process for managing project dependencies when you could use existing tools. I would publish those shared classes as a library and add it to each project using CocoaPods and a reference to the library's git repository. That way you just need to run a pod install to get the latest version of your library. A good dependency manager gives you a clear understanding of which version of your dependencies you're currently using, control over when to update them, handles installing dependencies of your dependencies, and will avoid link errors from multiple static libraries attempting to each include a copy of the same common dependency.