Develop Reference

External jars not loading in built project. NoClassDefFoundError

So, I have exported my project in both Netbeans and Eclipse and when I try to
java -jar myproject.jar
I get this prompt
In my project I have some libraries which are located inside of src in Netbeans and out of src in Eclipse as it should (please correct me if I'm wrong) The libraries are included via:
Java Build Path > Add JARs...
I've done some research and it seems that I have to change my JAVA CLASSPATH or somethng like that but I don't know exactly how to do it.
The project works perfectly when I compile it and run it, but it crashes after I build it into a Jar file.
By the way, if it isn't clear enough I'm on Ubuntu 14.04

You need to create the path for the jar files and pass it on the command line.
Something like this:
ftp_jar=${Utils_home}/bin/ftpClientUtil.jar
net_jar=${Utils_home}/bin/commons-net-3.3.jar
jsch_jar=${Utils_home}/bin/jsch-0.1.51.jar
java -cp .:$jsch_jar:$net_jar:$ftp_jar com.myplace.ftputils.SFTPClientUtil $*

Run your program as:
java -cp .:[path-of-lib1.jar]:[path-of-lib2.jar] -jar myproject.jar
replace [path-of-libX.jar] with actual path of your libraries.

Program runs fine in IDE but not as Jar file

I have exported a jar file that I want to run the console. The code compiles and runs correctly in eclipse but I am having an issue running it from the console.
To me it looks like the referenced jar's I added via built path in the Eclipse project file and not being added to the export. If that is the case, how do I ensure that they do? If not, what am I doing wrong?

When you export your source code's class files to a jar using eclipse, only the .class files of your source are exported! Hence your exported jar file doesn't contain the referenced jars you mentioned in eclipse! Due to this, the error occurs while executing from command prompt.
Solution:
Take all the jar files required to execute the program, store it in the same directory as you store the exported jar file. Now while executing the java command, provide all the jar file's names in classpath field as following:
java -classpath .;JAR1.jar;JAR2.jar MainClass
Once you do this, your problem should be resolved!

The dependencies need to be on the classpath, i.e. run like this:
java -cp <path_to_jar1>;<path_to_jar2> -jar ScrumTimeCaptureMaintenence.jar

When running from the command line make sure any dependencies are set on the class path by listing them in the -classpath parameter

compiling a packaged project dependent on a jar

This seems to me to be a trivial question, but I've had a lot of trouble getting an answer.
I've developed a project in eclipse that is dependent on a jar file, which resides in the project's root directory. All my files are in a package "a.b.c" in a src folder. It runs just fine in eclipse. I now want to run this project from the command line. I do this command to compile the project:
javac -classpath dependency.jar -d ./bin/ ./src/a/b/c/*.java
Everything is compiled into class files and put into the bin/a/b/c folder. Then I do these commands to run the project:
cd bin
java -cp ../dependency.jar a.b.c.Main
Now I get "java.lang.NoClassDefFoundError: a/b/c/Main".
So, how do I run a project that is in a package and depends on a jar file?

Just include the current dir in the classpath as well - i.e. java -cp ../dependency.jar:. a.b.c.Main

You also need to specify your compiled files on the classpath, these will contain your a.b.c.Main. On *nix flavor machines the path separator for cp is the colon (:), and on windows it's a semicolon (;), so on *nix, your run command should be (because you're running from the bin directory):
java -cp ../dependency.jar:. a.b.c.Main

Including jar files in class path

I m running a java program from a batch file which refences some external jar files .How do i include those jar files in my batch file.Please help

Look at the Sun's official documentation: Setting the class path to understand your options.
A quick way would be just to include your JAR(s) after the -cp:
on Windows
java -cp C:\java\MyClasses\myclasses.jar;C:\java\MyClasses\myclassesAnother.jar utility.myapp.Cool
on Linux/Unix
java -cp /opt/thirdparty/myclasses.jar:/opt/thirdparty/myclassesAnother.jar utility.myapp.Cool

You need to set classpath http://download.oracle.com/javase/1.3/docs/tooldocs/win32/classpath.html. E.g.,
java -cp file1.jar;file2.jar yourApp
or if your jar-files are located in directory lib/
java -cp lib/* yourApp

Not to bother with -classpath parameter you could put references to the jar files into the manifest.mf of your application JAR, if it's you application of course.
Adding Classes to the JAR File's Classpath

Sorry, I dont know others IDE, but works with me on Eclipse.
Right click on your project, select
Properties/ Java Build Path/ Libraries/ Classpath/ Add External JARs...
Then choose whatever files you need :v

You have to fill the Class-Path parameter of the manifest file of the JAR. The standard documentation explains that very well.

When running a jar or class file specify classpath option

Java Jar and Classpath problems

I've got a weird problem that I can't understand... I have a simple HelloWorld jar that I built in Eclipse which has the Apache Loggings jar on it's classpath. I've written a script to run the jar:
#!/bin/sh
export CLASSPATH=lib/*:$CLASSPATH
java -jar HelloWorld.jar
The directory structure here is a main directory with the HelloWorld.jar and a lib subdirectory holding the commons-logging-1.1.1.jar.
Running this script works fine. However, when I place the HelloWorld.jar into the lib directory (i.e. to contain all the JARs in one place), and executing java -jar lib/HelloWorld.jar, I get:
Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory
error. Why?!?!?!?!
I'm asking this because I've used the JarBundler on OSX to create an Application bundle for the HelloWorld app and placed a modified script in the MacOS directory whereas all the libs are placed in the Resources/Java directory. Modified version of the script is:
#!/bin/sh
RESOURCE_DIR=$(cd "../Resources"; pwd)
export CLASSPATH=$RESOURCE_DIR/Java/*:$CLASSPATH
java -jar $RESOURCE_DIR/Java/HelloWorld.jar
and I'm getting the same error as above I'd really appreciate any help understanding why I can't do this and/or how to fix it?

Classpath doesn't work with wildcards. Every jar has to be specified explicitly, either as part of the CLASSPATH variable or in the manifest of another jar that is included in the classpath.
Also, IIRC java -jar ignores all the third party jars that are present in the classpath. Why not do this instead?
java -cp yourJar:logJars <mainClass>

Try to add the commons-logging-1.1.1.jar to the CLASSPATH directly

Java will not work with lib/* but the shell may be expanding it for you. Double check this. Put a line like this after export:
echo $CLASSPATH
Also, I would recommend putting it in the MANIFEST file as already mentioned.
EDIT:
Is it a permission problem? If you run the app as root/admin or put the file somewhere else and use a fully-qualified path does it work?

Use the MANIFEST file (META-INF folder) to deal with Classpath entries. Use relative paths for the libraries.
For further info, take a look here.
Basically, for the case with commons-logging inside a lib folder:
Class-Path: lib/commons-logging-1.1.1.jar
And for both jars in the same folder:
Class-Path: commons-logging-1.1.1.jar

Thanks to everyone for their help in figuring this out. Basically, a manifest file was being created and bundled into the jar without my knowledge so any $CLASSPATH or -cp flags were being ignored. In my Eclipse project, I had my classpath set to $(projectRoot)/lib which coincidentally the same directory structure as my dist directory. However, when they were bundled into one directory by OSX's JarBundler, the directory was no long present, hence the classpath errors!
I tried removing the Class-Path attribute from the MANIFEST.MF that Eclispe created but the command line $CLASSPATH and/or -cp entries still don't seem to make a difference... Does the existence of a manifest file negate all command line classpath entries?

have you set log4j.jar into your class. i think you didnt added log4j.jar of to its class path.