I am currently using eclipse for working with Java. Additionaly I use git to synchronize my project between my laptop and my desktop PC.
The problem is now the following: I added external JARs to the project (Slick-Util, LWJGL).
But the path to each library is another on each device. So everytime I start working on the other device, I have to change the path to the jar files and the javadocs.
The libraries are all stored in my eclipse workspace. So the libraries and the projects are all in the same folder. And this folder is also commited with git.
Is there a way to change the eclipse settings (or do something else) so I do not have to change the path to the libraries and javadocs everytime?
I already googled and searched for it, but I could not find something about it.
Just don't add the libraries' jars to git. There are multiple build tools for java, which manage dependencies for you - you just state the libraries you're going to use, and the build tool downloads it for you at build time.
I would recommend Gradle, but Maven is also a very popular choice.
In gradle, you would create a file build.gradle, and define your dependencies in it:
apply plugin: 'eclipse'
apply plugin: 'java'
repositories {
mavenCentral()
}
dependencies {
compile 'org.lwjgl.lwjgl:lwjgl:2.9.0'
compile 'org.lwjgl.lwjgl:lwjgl_util:2.9.0'
}
Then you would run gradle eclipse from the command line - that would add the libraries you use to the classpath in eclipse. And when you want to compile and package your project you would run gradle build from the command line. You should read about it if you're going to use it, what I describe may not be exactly what you need.
Also, there are instructions for using LWJGL with maven.
add jar files to a lib folder inside your project like this : D:\Workspace\myproject\lib\your-jar-file.jar
then go to your projects build path select libraries tab and click on add jars and NOT add external jars this way your jar files path will be relative to your project
EDIT :
I highly recommend to use a build tool as Kiril Raychev described.
it will look a bit confusing to start with but after a while and after a normal growth in your application that will lead to using different frameworks, controlling and managing dependencies and their conflicts without a build tool will literally kill you.
You can simply use -f flag on add command.
git add -f test.jar
And, then commit and push to your repo.
Up until now i usually use svn so i'm not entirely sure how it works out in git, but have you tried to store the JARs in the lib folder of the project they are used in? (Eclipse displays the lib folder so you can easiely add them to the buildpath with a right click on the library in the package explorer.)
That way the relative location/path of the libraries to the project should stay the same. Furthermore if you plan to pack the project into a JAR later you ship the libraries inside that JAR without having to worry whether the user of that file even has them on his computer.
PS: Looks like i'm a minute too late. Dave basically said the same thing.
Related
I'll start this off by saying that I'm not a Java dev, I work in a .NET software house, but somehow we have ended up needing to modify some legacy java code.
So I have a project which I've opened up with IntelliJ IDEA Ultimate 2016.2. As far as I can tell this doesn't use Maven or Gradle or any other dependency management tool, and as I have no idea what I'm doing with Java projects I'm not going to start trying to understand that now.
I'm trying to add the Amazon AWS SDK to my project so I can upload some files to an S3 bucket. I've downloaded the SDK from the AWS site, and extracted the jar files into the lib folder of my project root. I've tried numerous ways of adding these as dependencies, right click the jar files and add as library, go into settings, modules, dependencies, click the plus and add the jars etc. When I build the project it builds fine, and intellisense if picking up the classes and methods when writing the code to utilise the SDK.
However, as soon as I run the app, I get a "java.lang.NoClassDefFound" for the com/amazonaws/AmazonServiceException package as the containing class is instantiated.
This could well be something to do with the "CLASSPATH" that I hear so much about (but don't fully understand), but my understanding was that IntelliJ handled this when adding the jars as a dependency. I've also tried adding all the jars from the "third-party" directory from the downloaded AWS zip file, and adding those as dependencies as well, but it still doesn't want to work.
Incidentally, I'm adding the jars to the lib folder so they are included in source control.
Any suggestions on how to use the AWS SDK without using Maven or Gradle?
Cheers
What I've done is to manually add all the jar files into the External Libraries.
Go to File > Project Structure
In the left window pane, choose Modules under Project Settings
Click on the Dependencies tab
Click on the + sign and select 1 JARs or Directories
Navigate to the folders containing the jar files (include third-party dependecies also) and click OK
See My IntelliJ screenshot
I'm kind of new to Eclipse and I'm hating it so far
The question is I'm working on a small project with some classmates, we are using Eclipse and Git but every time someone does an immport all the libraries are lost because they are referencing the computers path like C:/someone/something.jar and then someone else push something to github and the libraries path C:/someone2/somthing.jar
Every time, I and my partners have to search for the libraries on our pc so the errors stop appearing.
Is there an easier way so we don't have to lose time searching for the libraries on our pc?
You need Java build tool like Maven, Gradle to manage your dependencies.
In that way, it will resolve the libraries for you. And in the source code, you should not check in .classpath,.project meta files. Those files should be added into .gitignore to avoid commit.
To import projects into IDE (Eclipse in your case), Maven and Gradle can help you to generate those IDE meta files. Or some Eclipse plugins could be used to import maven or gradle project.
You should create a folder for libraries and put all jar files in there, add these files to classpath using Java Build Path Option from project properties. Also add this folder to git
I am using Eclipse Kepler for Java. Normally you can add internal/external .jars to a Java project in the build path located in the properties. Why, when I clone a git repo and import it into my projects, do I lose that ability? I don't understand. I kinda need to do that.
This is probably because the .gitignore has been configured to ignore .jar
Open the .gitignore file and remove the line *.jar, you should be able to add it.
======
As an aside - usually, for Java projects .jar files are not committed to repository (as they are large & it can slow down repository cloning), instead maven or gradle is used to configure dependencies. Example - http://www.mkyong.com/maven/how-to-create-a-java-project-with-maven/
Then when you want to work with eclipse just run mvn eclipse:eclipse to generate the necessary files. .gitgnore is usually set up to ignore *.class, *.jar, .project, .settings, .classpath
I found that if you open the run configurations and go to the Classpath tab that you can add internal/external .jars. The run configuration can be accessed by clicking Run > Run configurations. I added my .jar to the user entries. The bootstrap entry caused a null pointer.
When a project relies on libraries/modules, it's best to use a build tool for dependency management. JVM ecosystem is dominated with three build tools: Gradle, Maven and Ant.
How it works:
In a build script we declare dependencies of the project. This tells the build tool where to retrieve libraries/modules our project depends on. Dependencies are resolved at runtime; downloaded from a remote repository, retrieved from a local directory or if required another project to be built in a multi-project setting.
I have a plain Java project (not a plugin project) which I want to add to a classpath of a eclipse plugin which I am developing. But in web projects I can add that project as a build path and it works fine. But I tried same thing in eclipse plugin, I am able to compile successfully, but at run time I am getting java.lang.ClassNotFoundException.
I know OSGi quite well and I know how to add OSGi into an classpath (using export-packages) but what I want is to add Standard, non-osgi project into an classpath, so that I wont' get runtime errors. Is there anyway I can achieve this?
I can export project as a jar file or make it as a plugin project and it would work fine. But that's not my option currently because, still that API is in pre-alpha stage, and there would be lot of changes going on. So I am trying to avoid pain of exporting it as jar file everytime. Is there any option for me other than this?
I have a similar situation: I want non-OSGi Maven dependencies integrated into the classpath of my plugin. I succeeded with a roundabout solution, which I think is the best I could get.
I have a build step outside of Eclipse where I copy the class files of the dependency into the plugin's lib folder. The lib folder is specified in MANIFEST.MF as an entry in Bundle-ClassPath and (here comes the hack) as a source folder in build.properties. That was the only way to make the plugin work both when launched from within Eclipse and when exported.
I'm creating an eclipse plug-in and I'm having trouble with external jars. In my plug-in I start an application which requires some external jars. What do I have to do to export them automatically with the rest of the plug-in?
Thanks in advance :)
Open your plugin.xml
Go to Runtime tab and add your JAR in the classpath section
By following the steps below, the external JARs will be included when you export your plug-in:
Copy the required external JAR files into a folder in your plug-in project; I like to call this folder lib, but whatever works for you.
Open the build.properties in your plug-in project and check the JARs you want to include in the build in the Binary Build section on the left.
This is an easy way, though it does create an additional plug-in.
In Eclipse:
Choose New>Other, then Plug-in Development>Plug-in from existing JAR archives.
Choose the jars you want to include.
On the next page, configure the plug-in.
In your plug-in's manifest, add the new plug-in as a dependency.
In your plug-in's Properties, add the new project under Java Build Path on the Projects tab.
Edit: You may be able to combine the jars into your plug-in by instead combining both suggestions of Zsolt and user714965 below.
This is what has worked for me. If they are truly external, and this is a project for your company that is not going to be in the "wild" and you control the environment, and you have them out on the file system say at /opt/java/lib/somedir/some.jar you can tell the bundle where to find them by adding them to the Bundle-ClassPath entry in the MANIFEST.MF under META-INF. The syntax is:
Bundle-ClassPath: .,
external:/opt/java/lib/somedir/some.jar,
external:/opt/java/lib/someotherdir/someother.jar
Also it would be prudent to use these in your build path so that you are working with the same jars in both build and runtime environments.
I have done this where the Jars are multi-purpose (such as apache-commons) on our file systems and again we control the environment.
Reference the following:
http://www.eclipsezone.com/eclipse/forums/t51870.html
Copy the required external JAR files into a folder in your plug-in project; I like to call this folder lib, but whatever works for you.
..but as apposed to Zsolt Török (his solution did not work for me) I double-clicked on the plugin.xml, went to the build tab, at the bottom, I clicked Add JARs..., and hey presto, it showed my project, and I then navigated to lib and included the external jar, as per step 1.
The approach from Andy Thomas mostly works, but you also need to export the packages needed by the existing plugin in the new wrapper plugin so that they can be accessed by the plugin at runtime.