Eclipse JAR at runtime - eclipse

I'm importing several JARs all sitting in the same directory. When my program runs I'm able to access the classes in several of those JARs, no problem. So my classpath is fine (I assume). But there is one JAR giving me trouble. When I try to run:
Configuration conf = new BaseConfiguration();
I get a NoClassDefFoundError error. The searching I did on "NoClassDefFound" typically points to classpath problems but as mentioned above, other JARs in the same directory are being found so I think that's not the problem.
This is in Eclipse 3.8.
The import statements:
import org.apache.commons.configuration.BaseConfiguration;
import org.apache.commons.configuration.Configuration;
And the name of the JAR is:
commons-configuration-1.6.jar
Any ideas?
Tom

Perhaps it's failing to load a dependency of one of the classes in commons-configuration-1.6.jar? Maybe from another commons- JAR? The NoClassDefFoundError should tell you which class the runtime failed to load. Have you checked this?

Related

Eclipse Kotlin plugin not compiling Kotlin classes

Using Eclipse 2018.12, I've installed the Eclipse Kotlin plugin (0.8.20.20200316-1305), created a Kotlin project (using the "New..." options under "Kotlin") and wrote a "Hello World!" program:
Test.kt:
fun main() = System.out.println("Hello World!")
However, when I try to run it I get the message
Error: Could not find or load main class TestKt
Caused by: java.lang.ClassNotFoundException: TestKt
Upon further inspection it seems the class has never been compiled. There is no corresponding .class file anywhere. Under the project directory I see Eclipse configuration directory .settings and files .project and .classpath. Besides that, I have an empty bin directory and a src directory with Test.kt only.
I found two similar questions about this in SO:
In Unable to Run Kotlin Application in Eclipse, the accepted answer simply indicates working with a new version of Eclipse and Kotlin plugin, both older than what I have now. Besides, the problem may have been solved in that case due to a new installation rather than the version.
Kotlin - Error: Could not find or load main class _DefaultPackage is quite old and the accepted answer does not apply anymore. It was about not naming the main class properly, but in my case there is not even a byte code file to be found.
Running "Project -> Compile Kotlin classes" had no effect.
How can I get this simple example to run?
Update: I've updated to 2020-06 (not that it should matter since Eclipse Kotlin lists 2018-12 in its requirements) and replaced Zuly by AdoptOpenJDK HotSpotJDK 11. The error persists. The Eclipse log does not show any related messages.
Update 2: re-created the project in a brand-new workspace but the problem persists.

"Package HttpClient does not exist" when compiling

I am attempting to compile EWSJavaAPI1.5 in Eclipse and in IntelliJ. I have had no luck. I keep getting a org.apache.commons.httpclient does not exist error. Its driving me nuts. I added the four required files:
commons-codec-1.4.jar
commons-httpcliient-3.1.jar
commons-logging-1.1.1.jar
jcifs-1.3.15.jar
The four jar files are being referenced, yet it does not find the httpclient when compiling. It may have to do with the class path but I am not sure if I am adding it to the class path correctly. What to do?
Check that the library classpath is set correctly and this library is added to the dependencies of your module. Another possible case could be corrupted jar file, try to download it again.

Error in Eclipse about type indirectly referenced from required .class file

I'm having this exception with some stubs generateds by Axis2:
"The type org.apache.axiom.om.OMElement cannot be resolved. It is
indirectly referenced from required .class files"
I've been reading many posts, and trying to find a solution. What I've found so far is to add the apache tomcat 5.5 library to the build path. It removed the error in the java file, but then, when I to execute any java program inside the project, I got this error:
'Launching myApp' has encountered a problem Exception occurred
executing command line. Cannot run program "C:\Program
Files\Java\jdk1.5.0_22\bin\javaw.exe" (in directory
"D:\Digicel\workspace\Digicel\myClassSample"): CreateProcess error=87,
The parameter is incorrect
then if I remove the apache tomcat library from the build path, I can run the other java programs, but not the one mentioned initially.
Any thoughts about it?
Okay, I've found the cause of the problem with the help of a friend :)
The thing is that Eclipse is aware that one of my dependencies, depends of another library, and Eclipse is checking for it when it tries to build the code.
So, what I've done is try to check which jar file contains this library: " org.apache.axiom.om.OMElement".
I've googled it and found that it is "axiom-api-1.2.10.jar" and finally my file compiled with 0 errors.
He also explained to me that my original solution of adding the apache tomcat server library is adding all the jars that cames with apache tomcat (which is a big list), and probably there may have been a version conflict with my current list of added jars.
So, the fix was to find the appropriate jar and add it to the project.
This error can also occur when a indirect dependency has a corrupt jar file. This may be caused by problems at the public maven repository.
If this is the case removing the local maven repository to download fresh jar files will fix your problem:
rm -Rf ~/.m2/repository/{enter/path/to/broken/stuff}
Goto Maven >Update Maven project>checkmark the Force update >Then Run
..That error Will gone....

Only a type can be imported. org.apache.poi.hssf.usermodel.HSSFWorkbook resolves to a package

Trying to use Apache POI in a Eclipse JSP project. The POI jar is in the project's Java Resources Library list.
<%# page import="org.apache.poi.hssf.usermodel.HSSFSheet"%>
at run the following error occurs:
An error occurred at line: 7 in the
generated java file Only a type can be
imported.
org.apache.poi.hssf.usermodel.HSSFWorkbook
resolves to a package
Any ideas? Thanks
Don Lawton
The message indicates that the class could not be found on the classpath of your deployed application. Did you make sure that the POI jar is in your WEB-INF/lib folder?
Same happened to me, even when the needed jars were indeed in the WEB-INF folder.
I was using the provided server in SpringSource ToolSuite (STS). It took me several attempts to clean, republish, etc... before it finally worked.

noClassDefFoundError using Scala Plugin for Eclipse

I successfully implemented and ran several Scala tutorials in Eclipse using the Scala plugin. Then suddenly I tried to compile and run an example, and this error came up:
Exception in thread "main" java.lang.NoClassDefFoundError: hello/HelloWorld
Caused by: java.lang.ClassNotFoundException: hello.HelloWorld
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:315)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:330)
at java.lang.ClassLoader.loadClass(ClassLoader.java:250)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:398)
After this point I could no longer run any Scala programs in Eclipse. I tried cleaning and rebuilding my project, closing and reopening my project, and closing and reopening Eclipse.
Eclipse version number 3.5.2 and Scala plugin 2.8.0
Here is the original code:
package hello
object HelloWorld {
def main(args: Array[String]){
println("hello world")
}
}
If you see this when you attempt to run as a Scala application then the most likely explanation is that your project didn't compile and no class files were generated. Please check whether or not that's the case: look in your project's output folder for hello/HelloWorld.class.
If your project didn't compile that could either be because there's an error which you've missed (and if this error isn't being reported in the Problems view that could be a bug, in which case please open a ticket on Trac) or because you've turned off automatic builds and not done a manual build of your project.
I had the same problem. Project doesn't compile but there are no errors highlighted and AFAIK the code is OK. It seems to be a problem with the Run Configurations.
Solution 1: Delete the existing Run Configuration for your object and create a new one
Solution 2: Create a new object and cut / paste all your code into that file
When running "clean" does not un-hose Eclipse, I next try saving my work, exiting Eclipse, and re-starting. That usually gets things going again, but not always. A few times I've had to update the Scala plugin with a more recent version (I'm using the latest nightly), to get things working again. I doubt that this worked because the new plugin happened to fix the bug, but rather expect that loading the new plugin gives the whole Eclipse-Scala
system a "total reset" that gets it unhosed.
I was getting this problem in a project that combined .java & .scala files.
The solution for me was:
Remove all .java files
Edit the scala code as needed so it compiles without them.
Add the .java files back in.
Edit the scala code back.
The other solutions given here didn't work for me. I tried: clean project, restarting Eclipse, closing-&-opening the project, creating a new .scala file. No joy.
I'm using Eclipse 3.7 (latest stable), Scala IDE 2.0.0 and Scala 2.9 on Ubuntu Linux 11.10.
The symptoms in my case were:
My project was working, but then it stopped compiling for no apparent reason. The IDE didn't show any compilation errors for .scala files, but there were no .class files in the output directory & I got a NoClassDefError if I tried to run anything.
If I created a deliberate error in a .scala file, that did get picked up as a compilation error.
The .java files were registering errors due to the missing scala classes.
I suppose there's probably a boot-strapping bug somewhere in the IDE plugin for .java/.scala mixes. I've done hybrid projects with this setup without problems, so it's only triggered in some situations. I don't know what the trigger is, but once triggered, there's no nice solution.
I had moved my one and only class/object/application to a package, but had not added the package declaration.
sbt compiled and ran fine; eclipse would not
Adding the package declaration at the top of the file fixed it.
Scala 2.8.3 plugin; no compile error
I encountered this error too but after doing the suggestions here (cleaning, deleting Run Configuration etc), I realized that I set the workspace wrongly that is why the class is not being found.
An indication that this is a problem is when the same error occurs when you try to compile a java project.
I encountered this error (compilation worked in sbt but failed in eclipse) when I created a new package object called "common". Deleting the package object in eclipse caused the compile error to go away. There was nothing in it.
I was using sbt-eclipse to build the eclipse project. I'm using scala eclipse 3.0.0-vfinal-20130326-1146-Typesafe.