java.lang.Noclassdeffounderror occur when running from jar [duplicate] - noclassdeffounderror

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java.lang.NoClassDefFoundError on Android sdk and ADT 20 Windows 64
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Closed 9 years ago.
I import a .jar according to these steps:
under folder libs into you project root folder, I Copy my Jar files in this folder
and right click on the Jar file and then select Build Path > Add to Build Path.
The jar appears under Android dependencies.
But i have this error :
java.lang.NoClassDefFoundError: mypackage.MyClass
Please help me. I do not know how to solve it.

If you are compiling your JAR in a different system, you are probably using a different JRE.
try javac -version on both computers, and if they are differents, you can fix it focing the target JRE, like:
javac -target 1.6 -source 1.6 ...

You also have to add it to the "Order and Export" tab on the Build path.
Right click your project -> build path -> configure build path (assuming you're coding on eclipse.

Related

Java failed to bootstrap path, eclipse, jdk-13

I’m trying to update my JavaFX project to be compatible with JRE 13 (until now it was set up to use JRE 1.8). I’m developing with Eclipse 2020-03, using a Mac.
The first big issue I’ve had to deal with is the migration from the included JavaFX libraries in JDK 1.8 to having to import JavaFX (14) as an external package for JDK 13.
The second issue is migration from using the classpath to using the modulepath. I’m new to the module path, so what I say about it may not make sense, but my current setup now is this:
modulepath:
<list of other .jar files>
JRE System Library [Java SE 13 [13.0.2]]
JavaFX 14
<list of .jar files I downloaded, including javafx-swt, javafx.base, javafx.controls, javafx.fxml, javafx.graphics, javafx.media, javafx.swing, javafx.web>
<I created a User Library from the above listed .jar’s>
Finally, all the compiler errors are now gone (I had to recompile some of the external .jar files I downloaded so there weren’t any split packages), but when I build and run the application class nothing happens.
Checking the Mac system console, the below output seems to reference why the app is not starting, but I checked he JDK path and the referenced java executable does exist.
com.apple.xpc.launchd[1] (com.apple.xpc.launchd.domain.pid.java.40558): Failed to bootstrap path: path = /Library/Java/JavaVirtualMachines/jdk-13.0.2.jdk/Contents/Home/bin/java, error = 2: No such file or directory
What is happening here? If you need more info about my project config, comment and I can add details.

export with jdk 8 still got error when start server

I used eclipse with jdk 8 to export to jar. Yet i still get this error when start my server sfs
Exception in thread "main" java.lang.UnsupportedClassVersionError: sfs2x/extension/mmo/MMORoomDemoExtension$NPCData has been compiled by a more recent version of the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes class file versions up to 52.0
Could someone tell me how to fix.
I tried to uninstalled all java and install jdk8 only. But nothing change.
I had a similar problem, what fixed it for me was making sure that jdk8 was selected as the build jdk for that project (right click on your project in Eclipse and click on properties -> Java build path -> JRE System Libraries -> Workspace Default JRE, make ure that jdk8 is selected) and then recompiling. I was able to delete all .class files before recompiling as well, but that may be difficult if this is a project.
Best of luck.

Setting up LWJGL 3.0 with Netbeans

Downloaded LWJGL 3.0 from lwjgl.org, which only had the lwjgl.jar file in the jar subdirectory. The native directory only has files like libglfw.so but no subdirectories at all (and certainly not native/windows).
Created a library LWJGL30 with the lwjgl.jar file.
Added it to my project's library. and to the Project Properties->Libraries->Compile and Run.
Set the JVM launch argument in Project Properties->Run to -Djava.library.path=C:\Users\Owner\Documents\lwjgl\native for the VM Options
Copied the HelloWorld example from the link
Then ran and I get this error:
Exception in thread "main" java.lang.NoClassDefFoundError: Could not
initialize class org.lwjgl.system.Library at
org.lwjgl.system.MemoryAccess.(MemoryAccess.java:22) at
org.lwjgl.system.Pointer.(Pointer.java:22) at
org.lwjgl.glfw.GLFW.(GLFW.java:594) at
mylwjgl.MyLWJGL.run(MyLWJGL.java:43) at
mylwjgl.MyLWJGL.main(MyLWJGL.java:140)
C:\Users\Owner\AppData\Local\NetBeans\Cache\8.1\executor-snippets\run.xml:53:
Java returned: 1 BUILD FAILED (total time: 7 seconds)
I have checked, double checked, triple checked as well as searching online for an answer as it should work but it does not. Any help would be appreciated.
This error occurs when LWJGL is unable to find the native files. Make sure java.library.path actually points to the directory with LWJGL's natives (which have extensions like .dll, .so and .dylib). Be careful with spaces in the path: You have to wrap the path in quotation marks or it won't work.
The issue was I was running the HelloWorld example using the Stable version of LWJGL 3.0. When I switched to the Latest version, everything worked as expected.

I couldn't build Jhipster sample app

I'm trying to run Jhipster sample app in my Eclipse kepler . I've downloaded the project from here and I've imported it as existing maven project but it couldn't be build . I got this exception :
The type java.util.Optional cannot be resolved. It is indirectly referenced from required .class files AccountResource.java
and many "Undefined CSS file" errors
how can I run this project in my Eclipse ?
Normally you should create your application using the yeoman generator. Install yeoman and execute yo jhipster from your command line.
a)For the java exception basically you need to remove the old version of java from your build path and add support for java 8.
You need to follow these steps
1) Right-click on project » Properties » Java Build Path
2) Select Libraries tab
3) Find the JRE System Library and remove it
4) Click Add Library... button at right side » Add the JRE System Library(Workspace default JRE)
Do not forget to set the Java jdk compiler compliance level to 1.8 (Preference -> Java -> compiler )
b) The jhipster site mentions about the configuration settings(css,javascript and html etc)for eclipse to avoid errors in eclipe. https://jhipster.github.io/configuring_ide_eclipse.html

Android SDK tools rev 19: Issue with external jar files

I know this question was asked a couple of times on stackoverflow - but I still face some problems trying to add an additional jar file to an existing android project - using android sdk tools rev. 19.
Summary:
I use eclipse Version: 3.6.2
The project compiled and the artefacts worked with android sdk tools rev. 14/any android >2.2 (>= API 8)
The project does compile with sdk tools rev. 19/any android >2.2 BUT the artifacts do not contain the jars defined within the classpath - so I keep getting java.lang.NoClassDefFoundError exceptions
I tried to add "jar.libs.dir=lib" to my project.properties - since lib contains all the jars without any positive effect.
I also tried to create a new dummy project adding jars as I always did (all jars added to a lib folder within the project, right click on the jar > add to build path)
I tried to add the jars using import
Thank you for your help.
Rename your "lib" folder to "libs".