Develop Reference

Add AWS SDK to IntelliJ project without Maven or Gradle

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

Eclipse java libraries

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

How to put eclipse jdt jar libraries in Java Build Path?

I'm trying to use eclipse jdt, and I tried to import related modules in java source file.
I have a bunch of errors as the jdt libraries are not in Java Build Path.
I tried to open Add Libary -> Plug-in Dependencies, but it doesn't have the jdt jar files.
I could use Add External JARs to point to all the jar files, but I don't think it's a good idea considering I have to do the same thing over and over again with new projects.
In this case, how to put eclipse jdt jar libraries in Java Build Path? The java.util.Collection is found automatically. I guess there might be some easy way to setup so that jdt jar files are found automatically.

Assuming your project is an eclipse plugin project you can add the jdt as a dependency and the jars will be automatically added to the plugin dependencies

Normally, I had to use eclipse plugin for using jdt for accessing the files in the workspace, and getting the jar files and such.
However, I found this solution to be very useful for using jdt/ask. The idea is to use string as an input to the jet, and import the related jars for using the jdt APIs.
http://www.programcreek.com/2011/01/a-complete-standalone-example-of-astparser/
I had to open Configure Build Path.
Then, I could select and import all the jar files that I downloaded from the site.
Now, I am ready to use the libraries.

In you Java Build Path screen, you notice two bottons Add Variable and Add Liberary below Add External Jars. Use those options and define a new variable or new user library; Once done, add the same in the project build path.
For newer project, you can simply reuse the variable/user library.
java.util.Collection is found as it is added as library in your build path(see first item in your screenshot). I am suggesting to do the same by introducing an User Library.

Benefits in Android to importing a library internally vs externally

Post ADT 17, non-Android libraries need to be included either in the "libs" folders of the project or exported via the "Order and Export" tab in the build path. What's the difference (if any) between importing a library externally:
And internally:
Is there an advantage to importing a library in a way that it is included in the "Android Dependencies" group?

How do you add external jar dependencies into your Android project's build path (internally or externally) make no difference on the actual build process (more specifically at compile and dex step), all it does is to tell build process where to looking for the required jars at compile and dex step.
The Android Dependencies element shown in Java Build Path - Libraries window is just another abstract layer that ADT plugin used for managing/grouping jar dependencies. where your external jar files (in your case android-support-v4.jar) appears (inside or outside Android Dependencies) in that window makes no difference.
Since r17, dependencies management has been much improved, and it is recommended to use libs/ directory store all jar dependencies (refer to you internal way), which is considered as a automation approach (as ADT plugin becomes more smarter now), see Revisions for ADT 17.0.0:
New build features
Added feature to automatically setup JAR dependencies. Any .jar files in the /libs folder are added to the build configuration (similar to how the Ant build system works). Also, .jar files needed by library projects are also automatically added to projects that depend on those library projects. (more info)
However, you can still use the old way (refer to you external way) if you prefer, which is considered as a manual approach (as ADT plugin was stupid before), see Recent Changes‎ for r17 Release:
Important: If you are still referencing jar libraries manually instead of putting them under libs/ be aware of the following:
If the project is a Library project, these jar libraries will not be automatically visible to application projects. You should really move these to libs/
If the project is an application, this can work but you must make sure to mark the jar files as exported.
Is there an advantage to importing a library in a way that it is included in the "Android Dependencies" group?
Automation vs. Manual from dependency management perspective, automation is always considered as more errorless than manual in the world of computer science.

The number one, show stopping, 'I can't believe they didn't test this', disadvantage of putting external jars in the libs directory is that you can't set the javadocs location for them, as the option shows as 'None (non modifiable)'.
Hence I still use Export option in build properties

It has to do with library dependency management of Android. for details see http://tools.android.com/recent/dealingwithdependenciesinandroidprojects

From the Eclipse FAQ
An internal resource resides in some project in the workbench and is therefore managed by the workbench; like other resources, these resources can be version managed by the workbench. An external resource is not part of the workbench and can be used only by reference. For example, a JRE is often external and very large, and there is no need to associate it with a VCM system.
So, quite simply, if you want to be able to manage a JAR as part as the project, exposing it to SCM and such, then treat it as a internal resource otherwise, treat it as a external resource. It will not make any difference in the APK produced in the end, its simply a eclipse thing.
If you want to avoid creating a copy each time you want to use your library, treat it as a external resource. But, can I suggest you look into maven and the android maven plugin, maven has a bit of a learning curve (especially if you are used to "make" or "ant" style build scripts), but it is very much worth the effort.

Eclipse IDE- Add jar? Add External jar? Add Library?

I want to integrate TwitterAPIME to my Blackberry project. I have 3 Jar files provided by TwitterAPIME. I am not sure how to link these 3 Jar files to my project.
My basic doubts are
What is an External Jar ? What is a Library ?
What's the difference between Adding jar, Adding External jar or Adding Library ?

What is an External JAR?
External as the name suggest is a Jar file that is not built by the currently developing code. It is a utility Jar file that is added externally for extra features. It could be an API Jar file provided from the external site, just as in your case the 3 Jar files will be going to call External Jar Files.
To add an External Jar file in Eclipse, follow these steps: Right Click on Project -> Select Build Path -> Select Configure Build Path -> Library Tab in the following Dialog box.
What is a Library?
A Library is a in-built Jar file from the JDK Directory or any other software e.g. J2ME-Polish as you can see in the Image above. Normally these Library files are developed by a manufacturer.
What's the difference between adding JAR, Adding External JAR, and Adding Library?
Adding Jar File: When you have more than one project in Eclipse and you add another project's Jar file, that is called adding Jar File. There is a first Button in the Photo above, it only allows you to add Jar file from the other Project.
Adding External Jar: When you add any API Jar file provided by the site or another manufacturer. In your case the 3 Jar files are External Jar Files. You can add then by using second Button "Add External JARs".
Adding A Library: Clicking on the 4th Button will open a dialog box as below.
You can add different libraries installed on your system. You can also add your own Library, by selecting "User Library".

JAR: A JAR File in your workspace.
External JAR: A JAR File in your file system. Use it for test purposes only, otherwise your project would be quite untidy.
Library: Built-in libraries such as JUnit. You don't need to know their location, these come with Eclipse.

In addition to the excellent answer given above by Lucifer, I recommend that people looking to develop or use Libraries, review the following BB supplied KB article:
Working with Libraries - shared, bundled, releasing, and using 3rd Party SDKs
Where the API is available as source or a Jar, I have found it significantly easier to include the source directly in the application. For example, in this case, rather than include the TwitterAPIME jar, you could include the TwitterAPIME source as a separate project in the application. As well as being easier to build, this can help in debugging or at least understanding issues with the API.
You might also find this sample, and in fact the containing Thread, useful:
Twitter + Facebook Sample Integration

Also building on Lucifer's answer, I have used "User Libraries" to bundle jars that are used across projects and dependent on a 3rd party service. Specifically, in my case, JMS jars. If I upgrade to a new JMS, or a different provider, etc, I can simply change the jars in my User Library and all projects referencing this are updated. Rather than changing jar dependency in every project.

An external Jar is a Jar in a path outh of your Eclipse environment: i.e. outside of both Eclipse jars and projects generated jars.
A libraray is a collection of jars prepared by someone for you.
You can cerate a User Library by selecting a group of external jars: that is useful if you have a group o jars that should logically work togehter.
A further advantage of creating a library is that you can "reuse it's definition" by referencing it in multiple projects.
Use:
Project->Properties->Add library-> select "User library" and press Next->User libraries->New
insert a new name and later us "Add Jar" that adds any jar you need to you library definition.
Later use this library in your project.

Sometimes adding jars directly in the blackberry project might cause some build problems. Here 's a solution that works (90%):
You have your blackberry project. Now create a new simple Java Project.
Right-click on it > Properties > Java Build Path and choose Libraries tab and click on Add External Jars to add the 3 jars that are in your system and you want to use. Then OK.
Now go back to your blackberry project and Right-click on it > Properties > Java Build Path and click on the Projects tab, click on Add and select the project you just created and OK.
Now go back and build your Blackberry project.
I hope this help.

If you add the JAR within the Eclipse workspace, say /myproject/WebRoot/WEB-INF/lib but Eclipse does not display the /lib when using the Select Jar pop-up, exit the wizard and refresh WebRoot (rtClick and take Refresh or F5): Eclipse only shows new libraries not already added to the project and usually needs a manual refresh first.