Develop Reference

Java: could not find or load main class main - not sure why

I am trying to upload a .jar file onto eclipse in order to be able to edit it.
The purpose of the .jar file is to track player coordinates on minecraft.
I have decompiled this .jar file on Eclipse, using the eclipse Java Decompiler.
However, when I try to run this decompiled code, I am getting the error: 'Could not find or load main class main'.
This happens when I try to run the 'decompiled code' by creating a run configuration and specify the main class: 'main'.
I have looked at other forums on this topic and have tried different things without success. However, none of these options have worked.
The decompiled 'main.class' file is currently stored within the 'JRE system library' folder. Is this the wrong place to store it?
I would be so grateful for a helping hand!
I have provided an image of the decompiled code:
And the run configuration tab, where I specify how I want the code to run.

I have now created a plugin using 'Maven', which allows me to edit the code given that to use Bukkit as an API requires the tool 'Maven'.
https://bukkit.fandom.com/wiki/Plugin_Tutorial_(Eclipse)#Example_Files_and_Templates
Thanks so much for the help :)

Google OR-Tools: Using in an IDE

I have the Problem that i want to add OR-Tools into my project via eclipse IDE. I want to use the Linear Solver. I added the two jars form the downloaded Zip file. Now i want to run the SimpleLpExample from the OR-Tools site. I've got the Error that no jniortools in java.library.path. I see that at other posts they say you have to run make third_party and make java, but i don't know where i have to run these commands.
When somebody added it successfully into an IDE it would be glade when this person can explain how he does it. Thanks for help.

No. You need to add the path to the jniortools shared library I'm eclipse.
All dynamic libraries are located in the lib/ directory of the extracted archive.
To add the correct path, please follow these instructions:

Spring - Where to find the distribution jar files?

I will be starting to learn spring so I tried to download the latest sping version but I have encountered a problem and Im stuck. I can't find the distribution jar files. All I can see are java source files.
Here are the steps I did :
I went to this link projects
I clicked the Spring Framework link.
I checked the page and found nothing until I noticed the Cat Image
Download the zip and extracted it.
I checked the folder spring-core and found src folder. I tried to find any dist folder but found nothing except java files.
I did not bother to open all folders because I think it would be a waste of time.
Please help me. Im just starting to learn and now a bit frustrated.

1) consider all comments already given on your question, gradle and maven are very helpfull, and help you with nested dependecies
2) http://repo.spring.io/release/org/springframework/spring/

Sorting LWJGL in Eclipse

I'm having a problem with LWJGL and I just can't seem to find a working solution. I'm developing a game for my university project and when I run the 'SimpleGame' code, I keep getting this error: 'Exception in thread "main" java.lang.UnsatisfiedLinkError: no lwjgl in java.library.path'
I have been looking for a solution for weeks and it just doesn't seem to want to work. I've copied the jar files to a 'lib' folder within my project and created a folder for the natives which contain the necessary DLLs and I've put everything in my build path and tried multiple combinations of VM arguments.
I'm at my wits end with this. Any help would be greatly appreciated. Thanks.

I worked it out. I copied the 'lwjgl' folder (containing docs, jars, natives folders, etc) into a folder within my project called 'lib'. I hope this helps someone else in future as I've been trying to find a working solution to this for ages.
I edited my VM arguments so they looked like this (can't post a screenshot because I don't have enough rep yet):
-Djava.library.path="lib\lwjgl"
-Djava.library.path="lib\lwjgl\jar"
-Djava.library.path="lib\lwjgl\native"
-Djava.library.path="lib\lwjgl\native\windows"
I also made sure that 'lwjgl.jar' and 'slick.jar' were added to my build path.
Again, I hope this helps! Many thanks to #Crynix for advising me to check my VM arguments.

Why is there no manifest.mf in the “dist/” directory and why is jar file not working?

I'm new to NetBeans and I cannot find the MANIFEST.MF that this link tells me there should be when I click "Clean and Build" in the IDE.
However, I only see a .jar file and a README.TXT. Anyone have any idea about this?
I am completely new to NetBeans, so simple terms would be much appreciated!
Also, when I run my project in the IDE, it creates and displays a jFrame but when I double click the jar file, nothing shows up. I have done setVisible() and I have set the default close operation, so that is not the problem. When I was searching for an answer, I found out that this could be because I did not specify my main class in my manifest. So this may be tied in with the top question so that is why I am combining these two questions.
Thanks in advance, guys!
I am using NetBeans 7.2 Beta

I realised that the manifest.mf file is not located in the "dist/" directory but in the root directory of the project. I am able to locate it now. However, I am still unable to figure out why the jar was not working. It is working now. Maybe my machine was just acting up or maybe I was using up too much RAM so my computer did not want to run another program? Anyway, everything is solved now. Thanks for everyone to answered!

Extract the .jar file using WinRar and then check inside the META-INF folder for MANIFEST.MF.