Develop Reference

My Bukkit plugins has a plugin.yml but it gives this error [duplicate]

I am trying to create a Spigot plugin that allows players to use a compass to track other players. While exporting and running the server, I noticed that it was giving me an error:
[21:57:15 ERROR]: Could not load 'plugins\Manhunt.jar' in folder 'plugins'
org.bukkit.plugin.InvalidDescriptionException: Invalid plugin.yml
at org.bukkit.plugin.java.JavaPluginLoader.getPluginDescription(JavaPluginLoader.java:172) ~[patched_1.16.5.jar:git-Paper-683]
at org.bukkit.plugin.SimplePluginManager.loadPlugins(SimplePluginManager.java:148) ~[patched_1.16.5.jar:git-Paper-683]
at org.bukkit.craftbukkit.v1_16_R3.CraftServer.loadPlugins(CraftServer.java:389) ~[patched_1.16.5.jar:git-Paper-683]
at net.minecraft.server.v1_16_R3.DedicatedServer.init(DedicatedServer.java:252) ~[patched_1.16.5.jar:git-Paper-683]
at net.minecraft.server.v1_16_R3.MinecraftServer.w(MinecraftServer.java:1066) ~[patched_1.16.5.jar:git-Paper-683]
at net.minecraft.server.v1_16_R3.MinecraftServer.lambda$a$0(MinecraftServer.java:290) ~[patched_1.16.5.jar:git-Paper-683]
at java.lang.Thread.run(Unknown Source) [?:1.8.0_291]
Caused by: java.io.FileNotFoundException: Jar does not contain plugin.yml
... 7 more
I have never seen this error before and I'm not sure how to fix it. I have made sure to export the .yml file while in Eclipse, but it still shows me this error.

The plugin.yml file is a required part of a SpigotMC plugin that defines some basic information about the plugin like its name and the version of the Spigot API that it uses. For example, here's one for a Minecraft plugin I'm currently working on.
The error you're getting comes from that file not getting bundled into the jar. As a result, when the Spigot server tries to load your plugin, it can't find the plugin.yml because it's literally not present in your compiled jar.
I recommend setting up a build system like Gradle or Maven that will handle the complexities of building the jar for you independent of the IDE you use.
Set up a SpigotMC plugin using Maven
Set up a SpigotMC plugin using Gradle
I personally use Gradle, so feel free to see how I implemented it in one of my plugins. If you'd prefer Maven, there are many examples available including the popular Multiverse-Core.

You need the plugin.yml to run your plugin. If you're using spigot or bukkit, you should make your plugin.yml inside the src folder, in there, you need to include a minimum of:
name: (plugin name, no spaces allowed in name)
author: (your name)
version: (your plugin version)
api-version: (use 1.14)
main: (your main class)
description: (optional description, otherwise delete this line)
then you can export or rebuild the jar
This is an example of what my plugin.yml looks like:
name: ThornsPlugin
version: 1.0
author: MOREORLESS
api-version: 1.14
main: com.MOREORLESS.plugin.plugin
description: MC Stuff
Learn more about Plugin.yml here: https://www.spigotmc.org/wiki/plugin-yml/

JAssimp - Can't find dependent libraries

I've compiled the JAssimp library, and I'm trying to use the library in NetBeans with a project.
I'm setting the library path in Netbeans in the 'run' options of the project as such:
-Djava.library.path=D:\VB2013Projects\jassimpfinal\x64\Debug
That path is where jassimp.dll is located.
However, when I try to run my project, I get this error:
Exception in thread "main" java.lang.UnsatisfiedLinkError: D:\VB2013Projects\jassimpfinal\x64\Debug\jassimp.dll: Can't find dependent libraries
at java.lang.ClassLoader$NativeLibrary.load(Native Method)
at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1929)
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1847)
at java.lang.Runtime.loadLibrary0(Runtime.java:870)
at java.lang.System.loadLibrary(System.java:1119)
at jassimp.Jassimp.<clinit>(Unknown Source)
at opengltutorials.Mesh.loadMesh(Mesh.java:131)
at opengltutorials.Tutorial.init(Tutorial.java:124)
at opengltutorials.Tutorial.main(Tutorial.java:238)
I've checked the dependencies with Dependency Walker, and it shows that
Error: At least one module has an unresolved import due to a missing export function in an implicitly dependent module. for jassimp.dll. However, it doesn't show any functions in red, so I think this is just a red herring (I am probably wrong, though).
What's going wrong with this?

Fixed this by putting the appropriate .dll's in the working directory.

Didn't find class on path: dexpathlist

Seriously, i don't know what to do to solve this problem.
My android project was working fine, until i needed to import a library with Maven. Since that, everything started to collapse.
What is happening: When i start my application, the following error appears on LogCat and android tells that my app stopped working. I've searched for this similar error here AND on the rest of the internet, but everything people did haven't worked for me.
Error:
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.buscaserra/com.buscaserra.main.ActivitySplash}: java.lang.ClassNotFoundException: Didn't find class "com.buscaserra.main.ActivitySplash" on path: DexPathList[[zip file "/system/framework/com.google.android.maps.jar", zip file "/data/app/com.example.buscaserra-2.apk"],nativeLibraryDirectories=[/data/app-lib/com.example.buscaserra-2, /vendor/lib, /system/lib]]
Manifest and packages:
Build Path:

Same problem here.
What worked for me was adding android-support-v4.jar as a lib and making sure it was checked on Project properties -> Build Path -> Order & export.
It was mentioned here

I had the same problem when I moved the project folder from a Linux machine to a Mac.
What I did was:
Close the project
Remove the .iml file
Import the project using the "Create new project using existing code"
I am using IntelliJ.
Cheers.

I did the following steps to resolve the issue on Android Studio.
open file ./app/build.gradle
reduce compileSdkVersion (e.g. 22 -> 21)
click 'sync project with gradle file'
change back to the original compileSdkVersion (e.g. 22)
click 'sync project with gradle file'
recompile and it should work.

I have spent way to many hours on this stupid issue but finally got it resolved:
When creating a new project -> package name is causing this stupid dex issue to appear, must not be able to find the main activity during run time with whatever deployment assemply setup. Android Studio doesn't like some of my commonly used package names, I'm completely baffled..I think this is a pretty big bug haha
Given the following new project parameters:
Name: NotificationApp,
packageName: com.stores.business.notificationapp,
saveLocation: /home/me/AndroidStudioProjects/NotificationApp
I would get the following error:
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.stores.business.notificationapp/com.stores.business.notificationapp.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.stores.business.notificationapp.MainActivity" on path: DexPathList[[zip file "/data/app/com.stores.business.notificationapp-2/base.apk"],nativeLibraryDirectories=[/data/app/com.cvs.stores.myapplication-2/lib/arm64, /vendor/lib64, /system/lib64]]
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2327)
My Solution
I resolved it by changing the package name to:com.notificationapp, then File->invalidate caches/Restart..hope this helps someone else haha

Do you have any required projects on the build path? Can't tell from your screen shot but check your "Projects" tab. You may have inadvertently added a Project Library as a required project instead. Remove the project from the Projects tab and then project -> properties. Click Android, add the project as a library instead here...

Make sure that any compatibility lib jars that you're using in your main project (like android-support-v4.jar) are the same versions as those used in any of the projects that your main project references.
I had this same problem and what solved it was to copy and paste the android-support-v4.jar from another library project (that my main project was referencing) and pasting it into my main project's /libs folder.

I had the same issue.
Nothing had changed except Android studio and Gradle updated since I last compiled.
I took a look at the build options under Build>Edit Build Types and noticed that the one option that was different between my project that didn't run and the ones that did work was the Minify Enable option.
I set it to false and now everything works again.

I should understand the problem by just seeing "dex errors".But it took half day to fix the issue.
I fix this by following android developers page's instruction: https://developer.android.com/studio/build/multidex.html
First add this to my gradle.build:
defaultConfig {
...
minSdkVersion 14
targetSdkVersion 21
...
// Enabling multidex support.
multiDexEnabled true
}
dependencies {
compile 'com.android.support:multidex:1.0.0'
}
Then I extend my Application class (or declare the application class in AndroidManifest.xml or override attachBaseContext() function) as instructed by the MultiDexApplication class document on the page. This have fixed my problem.

ClassDefNotFoundError while class in classpath

I'm trying to run ParSeMiS. According to the documentation, it requires ant, prefuse and antlr jars to be available in its lib directory. I've put all the required jars in it. However, when I try to run it, I get the following error:
Exception in thread "main" java.lang.NoClassDefFoundError: antlr/TokenStreamException
at de.parsemis.miner.environment.Settings.parseFileName(Settings.java:198)
at de.parsemis.miner.environment.Settings.parseOption(Settings.java:312)
at de.parsemis.miner.environment.Settings.parse(Settings.java:170)
at de.parsemis.miner.environment.Settings.parse(Settings.java:122)
at de.parsemis.Miner.run(Miner.java:358)
at de.parsemis.Miner.main(Miner.java:61)
Caused by: java.lang.ClassNotFoundException: antlr.TokenStreamException
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
... 6 more
Now, I've verified that antlr/TokenStreamException.class is present in the antlr jar. I have tried adding the jar manually to the classpath by both exporting the CLASSPATH variable and setting it via the -cp switch. However, none of that works, and I still get this exception. Can anybody help me figure out what's wrong? Thanks.

The problem is that you're using -jar which ignores your CLASSPATH environment variable. You should list your dependencies in the manifest, as shown here, e.g.
Class-Path: lib/ant.jar lib/antlr-3.4-complete.jar lib/prefuse.jar
(It should have still worked with an explicit -cp option, however. My guess is that you got something wrong when specifying that, and assumed it was the same underlying cause as the failure when using the environment variable.)

I realize this question is very old, but I just had exactly the same problem and found this thread. For posterity, I'm posting how I did eventually get it to run:
As mentioned above, when running with -jar, java apparently ignores the class path. So don't run it with -jar. instead include the jars in the path and run the class directly. Poking around, the following should work (paths are on my Ubuntu 12.10 system):
java -cp /usr/share/java/antlr.jar:/full/path/to/parsemis.jar de.parsemis.Miner
You can then pass in options to the above. Maye sure you use full paths, and no shortcuts like ~/foo, as they apparently don't expand.
Of course, if you're using a Dot-formatted graph like I am, it dies very early on complaining of "unexpected char 0xA", but at least it gets further.

getting javax.mail.MessagingException

I am using javax.mail .jar file to read the mail messages. But when i m running the code i am getting the following exception.
I added mail.jar in classpath.
Exception in thread "main" java.lang.NoClassDefFoundError: javax/mail/MessagingE
xception
Caused by: java.lang.ClassNotFoundException: javax.mail.MessagingException
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
Could not find the main class: MasterProcess. Program will exit.
any suggetionsn to solve this issue please ...

You're not getting a MessagingException, the VM is complaining that it can't find MessagingException (although it's probably that it's looking for it because it wants to throw it, but those are issues for later).
Check if your mail.jar actually contains this class, and check if your mail.jar really is on the classpath.
The last thing that could happen is that the class is incompatible with your version of Java. Classes compiled for 1.5 won't run on 1.4, for example.

Working in eclipse and not in command line clearly say that there is multiple versions of mail jar present in the project.
Ex:
You have 3 Jars , Jar X, Jar Y and Jar Z.
With out you knowing JAR X might be already be bundled inside JAR Z ( in this case mail jar but some different version.
So what is the problem in having multiple version of same jar ?
You have two different versions and you will not know which will be referenced in your project. (so if you are looking for some class from mail-2.jar in your project you will get class not found exception if the reference is made to mail-1.jar by class loader)
So how come its working properly on Eclipse ?
In eclipse you can see there is an option for ORDER the library, these will be reference in the same order, but while running in command prompt we used to load the as lib/* which loads all to gather and we will not know which lib will get loaded first.
How to identify the culprit and fix the issue ?
Option 1 :
See docs page / user guide of the libs you are using to see what they have in them.
Option 2 :
In eclipse move the JAR in question (mail.jar here) to TOP in the class path order. (your program should work now)
Now bring down the order one by one to see where you get the error. (if you wish to find the jar which is causing this issue , duplicate reference)
Extract the jar which has the duplicate reference remove the duplicate inside the JAR and repackage it. (if required)

Also be sure you're having also the java activation.jar jar.
Are you by any chance working with an App Server (eg. Jboss), if so, just check classloading model (in jboss with single classloading model you may be loading a not so up-to-date version of the jars)

I've also faced the same error. It happens to me that while compiling i used the jars correctly. While running it on command line i noticed the mail.jar (javamail API) was not included.