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Where to put Java libraries?

I'd like to know how I can add Java libraries to an Eclipse project on a development machine so that they can be added to an Eclipse project without causing errors when someone who has the library in a different location. For example, one developer might add an external JAR in C:\Java, but another might have the same JAR somewhere else. (Where's C:\Java on Mac OS?) I thought I might set the CLASSPATH environment variable, but I can't figure how to add an external JAR from the CLASSPATH environment variable. I'd like to do this so that it works with any workspace. Is this possible?
This is specifically for use with Anypoint Studio, but I think the same problem would exist with any Eclipse-based IDE.

In general, it's recommended to either embed JARs directly into the project, usually in a /lib folder of the project, as described here; or to use a tool like Gradle or Maven to manage dependencies, both of which have nice plugins to support their use in Eclipse.
Another alternative would be to use a Classpath Variable to refer to the JAR(s), which abstracts the physical location so that it can be set on a per-workspace basis.

I think the best way to add library to eclipse project is creating a directory - lib in your project directory. Then add the whole lib to you eclipse class path. You can follow these step to add a lib to class path -
Right click on project and select properties
Select Java Build Path
click Add Library and create User Library
Now add External Jars to this library create at step 3.
By this a .classpath file is crated in you project directory and the CLASSPATH problem will be resolved

I guess the best way to do that would be using Maven, or a similar build system that can construct your Classpath base on dependencies.
You can add the dependencies to your pom and having the jars in your local maven repository in the machine.
http://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html
Because in any other approach you will need to maintain everything manually, and when having different OS the path will change.

Eclipse is just the IDE that will help to write code and assemble the project (JAR, WAR, ... ). You can add your external jars from wherever you want, and when you want to export your project (with eclipse) you may choose to package the required libraries into the jar.
However, I recommend always to use maven (or something like ) to avoid this kind of problems.

Part1:(import .jar file as library in Eclipse)
You make a new project to Eclipse(name:Project1)
When you open it you see JRE System Library[java version something]
1.right click on JRE System Library
2.Go->Build Path->Configure Build Path
3.You can see (Up right Corner the button[add jars or add external jars]
*Here i advise you to choose the first(add jars) but..
*First copy(or move) the (name).jar inside the project((example):Project 1)
*Now you can add it with the button(add jars).
*In this way when you finish your project the (name).jar will be
imported inside the project(If you export it as a .jar from Eclipse)
..Now you can call any method of (name).jar just(import it into the class
you want to use and call it)

how to share user libraries across multiple systems without exporting and importing

I am a newbie, Please bear if i am silly. I have created a java project in eclipse which uses includes multiple jars like Apache Commons DBCP, dbutils, commons pool and some mysql jdbc driver. Instead of adding these jar directly to the project, i want to create different user libraries one for each and add the respective jars and its source and its javadoc into it.
So i created the user libraries and added the respective things in it and added those user libraries into project. Everything is fine upto that. But I want to work with same project in my home machine and when i imported that into eclipse in my home machine, those user libraries are empty. I undestood eclipse stores those info in the workspace and in my new workspace i am not able to use that libraries.
So i tried creating a new folder "lib" in the project and added all those jar into that folder which will always go with the project and when i creating the user libraries, this time while adding the jars i selected the option add jar-> workspace->lib->... and added those jar into the user library assuming that the lib folder is within the project and so the user libraries stay accros the workspaace but i failed again. Its working out. So how can use the libraries in different workspaces without importing and exporting... Please help me...
I do know ${project_loc} will give the project location. So is there anything i can say ${project_loc}/lib/commons-dbcp.jar to the user libraries.

I think you are viewing Package Explore
Open the Project Explorer instead.

I'd rather suggest to look at Apache Maven, which does allow you to configure dependencies for your project and build it (almost) everywhere.
It also has some plugins for integrate with Eclipse, so you can share your project easily without copying libraries manually.

Can I refer to a Java source path using a variable in Eclipse

Background
I'm using an Eclipse 4.2 (Juno) release to build a plugin for a Java application. The source code and classes for my plugin all reside within the project workspace. The application jar and its source code are, for various reasons maintained outside of the eclipse workspace and the application jar is produced by another build mechanism.
This isn't a problem as I have referenced the application jar file in my project using drag and drop and the 'Link to files' option specifying it 'Create link locations relative to: MYDEV', where MYDEV is a Linked Resource Variable I have created for each Eclipse installation. This lets me use the same eclipse project on multiple machines where the path to the application jar varies, but is always the same relative to MYDEV.
However, I cannot find a way to associate the application source code with this jar unless I use an absolute path. I only want access to the application source for debugging purposes.
Question
In Eclipse, how do I attach java source to a referenced jar in a way that allows a project to be used on multiple installations where the referenced source code has been relocated?

If the source is outside the proyect, then there's no way to access it without an absolute path.
The best solution is using a symlink inside the eclipse project directory to the actual source folder; eclipse won't notice the source is outside the project directory and everything will work fine, without having to relocate the source.

This is the only way I was able to do what you are suggesting (do not know if there are better ways).
Package a JAR file that contains the source code of the JAR file. Place it inside your project in a folder (you do not need to add it to your class path)
In the eclipse project right click on the JAR file and go to "properties" and then to "Java Source Attachment" From there select "Workspace" button and pick the jar file with the source code we added from the above step.
So the source attachment path will always be relative to the project. That way if you share the project via SVN, GIT or whatever, the source will always be available and it'll work if the user is running eclipse on Windows or Linux.
I've had a similar problem to you where absolute paths were a problem for people using different OS and not even using mapped drives via Samba helped that much.
Hope this helps.

The way I have solved this problem is to use a use defined library in eclipse. Here the steps that you can use to solver this problem.
Create a simple project in eclipse in the directory that contains the jars and the source code files.
Define a java user library add the jars to the user library and for each jar in the library specify the location of the source. If the source files are in a project that is in the workspace then the path will be relative to the workspace folder.
Export the user library as an .xml file
When another use wants to setup an eclipse workspace with the same setting as yours they will do two things.
Import the project that contains the jars and the sources into their workspace.
Import the user library into their workpsace.

After building the project from pom.xml using Maven, how do I use its resources

It's been tedious. This is the API I am trying to use. Its resources were set up in a pom.xml which I built using Maven. On built up, it gave me the project socrata-publisher that has
src/main/java the source folder with packages com.socrata.api com.socrata.data, com.socrata.util where each contains only .java
files
JRE System Library and Maven Dependency hierarchies where each contains a number of jar files
Problem is com.socrata.api and the 2 other contains classes which I want to deploy in a project outside socrata-publisher. I tried using import com.socrata.api but it didn't work. Moreover, since its a Java project and not android it doesn't have the is Library option in preferences which could rather give me the solution. Both socrata-publisher and tutorial (where i want to use the resources and which is the android application) lie in the same directory eclipseApps in My Documents.
Here's a little visual queue. Help will be greatly appreciated.

You will need to first of all get the output of the socrata project and all its dependencies.
In command line, going to the project folder of the socrata project, where the pom.xml file is, run MVN INSTALL. You shall see a jar file called socrata-api.jar in $HOME/.m2/repository. If you are using windows and installed MAVEN by default, $HOME should be your user profile folder. Once you see the jar file, add it to your tutorial build path.

I think what you actually want to do is just set up the "socrata-publisher" as a project dependency for your "tutorial" project. That will allow you to reference the built Socrata libraries from the code in your project.
Right click on the project and select "Properties". From within that dialog select "Java Build Path" on the left, then the "Projects" section, and click the "Add" button to add the "socrata-publisher" project.
I think that'll work better than creating a separate jar file that you then include, and then you can also keep the socrata-publisher code up to date using Git.

How to get Netbeans 6.5 shareable libraries working

I created a Web application in Netbeans 6.5. Now I want to use the Joda Time library. I want to share this library via subversion, because I don't want my team mates to be dependend on some Netbeans configuration.
Just to get the project working, I first added the library to the Netbeans library (Tools->Library). This worked OK. The JAR is added to the classpath, and is also deployed.
But when I create a shared library (via Project Properties->Libraries->Browse/New Libraries Folder), the JAR is not in the classpath. I get the error message package org.joda.time does not exist on the code import org.joda.time.*.
Any ideas?

What is the scope of this library? Is this library used for just this particular web-application?
If so, can we put the library in the WEB-INF/lib directory and check that into subversion as well?
Libraries in the WEB-INF/lib directory should be automatically added to the classpath of the project.

Here is what I did:
Tools -> Library -> New Library...
called the library joda-time
add added the joda-time-1.6.jar file to it
Project -> Properties -> Libraries
under the compile tab
Add library...
selected joda-time
(Edit, think I see the issue now - but perhaps not).
You need to add the library to the compile libraries AND add it to the distribution libraries. Or am I misunderstanding the question?

when creating a 'new project', there is an option to enable 'dedicated folder for libraries'. That way, the libraries will also be committed to the repository and your peer developer can checkout your project with all the libraries, your project has dependencies upon, thereby eliminating netbeans configuration bound.

In scenario where a project depends on JARs which can be placed in different locations for different users, a named IDE variable can be used.
http://wiki.netbeans.org/NewAndNoteWorthyNB65#section-NewAndNoteWorthyNB65-VariableBasedPathsInJ2SEJ2EEProjects
Another option would be to use the Maven plugin which already works quite well in NetBeans 6.5. A Intranet repository for the Artifact Jar files could be placed on a file server, or managed through a Maven Proxy like Nexus.

This blog entry describes a hack that worked in NetBeans 5. I don't know if it will work in NetBeans 6.5. I also don't know if this will work if you are building files nightly on a server.
http://blogs.oracle.com/gjmurphy/entry/using_netbeans_free-form_projects_as
I remember setting up shared libraries like this 8 years ago in JBuilder. I wish Netbeans had it by now.