I have a project in eclipse which was working fine untile a few minutes ago. I added a JDBC driver ad tried to run it, now even previous runnable file are giving me
Exception in thread "main" java.lang.NoClassDefFoundError: sample
Does anyone have any idea why it is happening does it have anything to do with the jar?
I have even removed the jar.
Try following, one by one
If you are using libraries, check whether everything is included to the project properly.
Rebuild the project
'worked few minutes ago' means it used to work. Did you add any new code? Then the error is there, check whether those codes call other classes, and whether they are available
Restart IDE
Once I used the following to solve the same issue
http://javarevisited.blogspot.com/2011/06/noclassdeffounderror-exception-in.html
If all above failed, that may be due to crash in JVM. I have experienced that as well.
Related
I have had this problem for years and years now where Eclipse would sometimes, seemingly for no reason, throw this error:
Error: Could not find or load main class [main-class] Caused by: java.lang.ClassNotFoundException: [main-class]
This error fires despite the class being in the file system and having previously worked with no flaws. Project clean does not fix it, and the filepath is completely valid. Consequent Google Searches usually turn up recommending that it's one of those two problems, or that you have to completely delete the project, or create a new workspace - so on.
I'm not sure what the exact cause of this problem is, and I haven't ever really been able to find one neither. However I had found a relatively simple fix for correcting it.
To fix this problem, what I've learned is that for some reason it tends to be Run Configuration itself. What you can do is:
Click "Run" in the toolbar
Click "Debug Configurations"
Create a new Run Configuration (However, don't just copy and paste the old one - for some reason this doesn't always fix the problem for me)
Set it up appropriately for the class, you can however copy the parameters from the old
Save and use that as the new run configuration for your program
This has generally fixed the problem for me most times. Hopefully someday Eclipse will have this properly fixed.
My current Eclipse version is 2021-12 (4.22.0)
I don't know if I did this self-answered question thing correctly, but for those of you who are banging your heads against your keyboard on Google right now trying to fix this, I hope this helps.
So in the past days i've decompiled minecraft 1.12.2 using mcp to make an "own" client. I ran it from eclipse and all was working just fine. But once i exported it, added the needed JSON file and started it from the minecraft launcher, it resulted the following error:
Exception in thread "Client thread" java.lang.NoSuchMethodError: org.apache.logging.log4j.Logger.info(Ljava/lang/String;Ljava/lang/Object;)V
at net.minecraft.client.Minecraft.<init>(Minecraft.java:420)
at net.minecraft.client.main.Main.main(Main.java:115)
In my opinion that'a a bit strange, because when I ran it from eclipse that error did NOT occur.
I was thinking about adding the logger in the specific JSON file for the version but I do not know how to do it. I took the JSON file from a video where I expected my problem to be solved, made some changes, but it didn't. I also put the folder containing the logger-jar (org.apache....) in the client jar, but still no success.
Also i just decompiled 1.12.2 and recompiled it right away to see if i had messed up my code some how.
I hope someone can help.
This means at runtime you have a class that is different than what you had at compile time. You should try unzipping the jar and searching for the class file. It sounds like you need to potentially remove it and replace it with your own version.
Thanks to all who viewed an wanted to help!
Now I found an other way to use it. I wanted to export it to test
it on my server. But instead I used my account credentials to log in directly from eclipse.
:)
So I'm running into a Jar hell problem when trying to run individual integration tests, using -Dtest=, that runs as a ESRestTestCase (ESTestCase). The issue here seems to be that some elasticsearch classpath validation class requires target/classes to exist. However, this project is only for testing so that requirement doesn't make sense.
This happened with Elasticsearch 7.0.0 and Java 1.8.0.251. Not sure if this is a problem with later versions.
java.lang.RuntimeException: found jar hell in test classpath
at org.elasticsearch.bootstrap.BootstrapForTesting.<clinit>(BootstrapForTesting.java:98)
at org.elasticsearch.test.ESTestCase.<clinit>(ESTestCase.java:229)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:348)
at com.carrotsearch.randomizedtesting.RandomizedRunner$2.run(RandomizedRunner.java:623)
Caused by: java.nio.file.NoSuchFileException: <MY PROJECT FOLDER PATH HERE>/target/classes
at sun.nio.fs.UnixException.translateToIOException(UnixException.java:86)
at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102)
at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107)
at sun.nio.fs.UnixFileAttributeViews$Basic.readAttributes(UnixFileAttributeViews.java:55)
at sun.nio.fs.UnixFileSystemProvider.readAttributes(UnixFileSystemProvider.java:144)
at java.nio.file.Files.readAttributes(Files.java:1737)
at java.nio.file.FileTreeWalker.getAttributes(FileTreeWalker.java:219)
at java.nio.file.FileTreeWalker.visit(FileTreeWalker.java:276)
at java.nio.file.FileTreeWalker.walk(FileTreeWalker.java:322)
at java.nio.file.Files.walkFileTree(Files.java:2662)
at java.nio.file.Files.walkFileTree(Files.java:2742)
at org.elasticsearch.bootstrap.JarHell.checkJarHell(JarHell.java:199)
at org.elasticsearch.bootstrap.JarHell.checkJarHell(JarHell.java:86)
at org.elasticsearch.bootstrap.BootstrapForTesting.<clinit>(BootstrapForTesting.java:96)
... 4 more
At first I tried various methods for making sure the classes folder was still created. I ran into new problems that seemed fixed in later versions so I upgraded to Elasticsearch 7.6.2 (And lucene 8.4.0). Upgrading seemed to remove the need for the folder to exist but triggered other issues (similar to this). I worked around such issues with -Dtests.security.manager=false. Then I got thread leak issues which I "solved" by setting #ThreadLeakScope(ThreadLeakScope.Scope.NONE) on the test class.
Then finally it seemed to work when running maven in command line for individual tests. But when trying to run the maven task with debugger in Intellij the debugger does not seem to attach.
So I try to run it as JUnit templated test in Intellij. Here I get jar hell when running it but it works to debug. The jar hell was later solved by setting idea.no.launcher=true in idea.properties.
Alright, good enough for now. These workarounds are far from ideal but it works for my current purposes. A lot of things will change before moving into mainline anyway. And maybe this will help someone else. Hopefully I can post a better solution later.
I am trying to debug a Java / Maven project with a lot of depencies on various libraries.
When I run it on a Linux server the program starts up fine, but when I try to run it in Eclipse it throws the following exception:
Exception in thread "main" java.lang.NoSuchMethodError: org.apache.camel.model.RouteDefinition.getErrorHandlerBuilder()Lorg/apache/camel/ErrorHandlerFactory;
at org.apache.camel.spring.spi.SpringTransactionPolicy.wrap(SpringTransactionPolicy.java:69)
at org.apache.camel.model.PolicyDefinition.createProcessor(PolicyDefinition.java:133)
at org.apache.camel.model.ProcessorDefinition.makeProcessor(ProcessorDefinition.java:437)
at org.apache.camel.model.ProcessorDefinition.addRoutes(ProcessorDefinition.java:183)
at org.apache.camel.model.RouteDefinition.addRoutes(RouteDefinition.java:817)
at org.apache.camel.model.RouteDefinition.addRoutes(RouteDefinition.java:165)
at org.apache.camel.impl.DefaultCamelContext.startRoute(DefaultCamelContext.java:697)
at org.apache.camel.impl.DefaultCamelContext.startRouteDefinitions(DefaultCamelContext.java:1654)
at org.apache.camel.impl.DefaultCamelContext.doStartCamel(DefaultCamelContext.java:1441)
at org.apache.camel.impl.DefaultCamelContext.doStart(DefaultCamelContext.java:1338)
at org.apache.camel.impl.ServiceSupport.start(ServiceSupport.java:67)
at org.apache.camel.impl.ServiceSupport.start(ServiceSupport.java:54)
at org.apache.camel.impl.DefaultCamelContext.start(DefaultCamelContext.java:1316)
Now, I can see that the RouteDefinition class is in the camel-core-2.9.3,jar and I can see that this library is imported. So how come it doesn't see that method?
How do I go about debugging this?
Could I get info from the process running on the Linux server? For example can I get the list of Jars that are imported and the order in which they are imported?
Many thanks!
The error that you're getting is caused by Maven pulling in the wrong version. Try deleting all versions out of your local repo, add it explicitly to your pom, clean out all of your builds, pray to the eclipse gods, etc. If it still gives you the error, check your local repo to see which wrong versions it pulled in, figure out what depends on them, and add explicit ignores for them while keeping the explicit include.
Everything works fined, but suddenly eclipse stopped execute and junit tests or even main method, when i run them using run as - > Java application, run as -> junit test
It simply throws error
Caused by: java.lang.ClassNotFoundException: package.ClassName
whene ClassName - is class from where i trying to run method main.
It affect only one of my projects ... Different workspaces works fine, other project in same workspace works fine as well.
I'm sure if i recreate current project, error will gone. But the adjustments of this project in eclipse is really hard, so i want to avoid it.
Any clue?
The ClassName is not in the Class Path, if you start from console you should use -cp parameter , if from eclipse, please add ClassName to the sources of current(start) project.
Thanks to adarshr, I was able to look at the Problems window and determine that the build was failing because it could not find a class I had written.
I had used the MS TFS plugin to create a "shelveset" and it was supposed to have removed my pending changes in the process. However, this integration with the TFS snapin and Eclipse is obviously not well implemented, since the Eclipse project still thought the file existed and was complaining that it could not be compiled.
I went and manually deleted those "files" or "non-existing files" from the Eclipse project (that I thought I had removed with the shelveset action) and the problem was solved.
Also....
Another annoying things is that the Tomcat error I was getting by trying to debug within Eclipse was like this:
SEVERE: Error configuring application listener of class
com.CompanyName.ProjectName.servlet.StartupConfigListener
java.lang.ClassNotFoundException:
com.CompanyName.ProjectName.servlet.StartupConfigListener at
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1643)
In reality, there was no problem at all with StartupConfigListener.java!! The build failed due to the OTHER problems I mentioned above, and therefore I guess this was the first class it attempted to load and failed.... because the entire project hadn't been able to compile perhaps?
(Here's to hoping my next project is using Visual Studio instead of Eclipse!)
Ok, I finally figured it out. The problem was with installed JRE in eclipse setting. I was playing around with this setting and changed installed JRE to JDK, and for some reason it broke the eclipse project.
You can also try going back to the basics. Check your command line and VM args. I've had this situation where a VM arg I was passing in was a path to a file that had a space in the path, and I had forgotten to include the full path in quotes. So e.g., if my arg looked something like
-DFILE=C:\Documents and Settings\myfile
...I'd get a java.lang.NoClassDefFoundError caused by a java.lang.ClassNotFoundException.