I am starting off with JUnit in Ubuntu and tried to execute the sample program given here. I have also followed instructions as given in the same link. The code compiles succesfully but gives runtime error as follows:
Exception in thread "main" java.lang.NoClassDefFoundError: org/junit/runner/JUnitCore
at TestRunner.main(TestRunner.java:7)
Caused by: java.lang.ClassNotFoundException: org.junit.runner.JUnitCore
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 1 more
So far this is what I have got. This error occurs if the $CLASSPATH variable isn't set to the location of the classes required by it.
> echo $CLASSPATH
/home/webyog/workspace/JUNIT/junit-4.11.jar:.
My java files and class files are in /home/webyog/JUNIT_WORKSPACE/ and all the libraries and the JUnit jar file is in /home/webyog/workspace/JUNIT/.
I executed these in order:
javac TestJunit.java TestRunner.java -classpath /home/webyog/workspace/JUNIT/junit-4.11
(This generated 2 files TestRunner.class and TestJunit.class)
java TestRunner -classpath $CLASSPATH
(This gives the error)
What I am I missing? Please help.
In your question, you have /home/webyog/workspace/JUNIT/junit-4.11.jar:. for $CLASSPATH but state:
the JUnit jar file is in /home/webyog/JUNIT/
(note the workspace missing)
That could explain the error you are seeing.
Try with:
cd /home/webyog/JUNIT_WORKSPACE/
java -cp '/home/webyog/JUNIT/junit-4.11.jar:.' TestRunner
Also you might want to check out some build tool to make you life easier (maven, ant, gradle, ...)
Related
For various experimentations, I take care of a java project in github.
After the Maven build, the program runs with a script bat.
Now I opened a branch because I would use the library args4j to parsing the arguments.
The build works fine, the jars exist in the directory lib, but when I run I have this stacktrace of Exception
Exception in thread "main" java.lang.NoClassDefFoundError:
org/kohsuke/args4j/CmdLineException
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2625)
at java.lang.Class.getMethod0(Class.java:2866)
at java.lang.Class.getMethod(Class.java:1676)
at sun.launcher.LauncherHelper.getMainMethod(LauncherHelper.java:494)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:486)
Caused by: java.lang.ClassNotFoundException:
org.kohsuke.args4j.CmdLineException
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
... 6 more
in bat I configured the classpath so that the args4j jar in in lib: this are the instructions of bat script
SET JAVA_DIR=C:\Program Files\Java\jdk1.7.0_80\bin\
>CUT
"%JAVA_DIR%\java" -jar ".\lib\buildCSS-1.0.jar" -cp ".\lib\" -conf "./conf/environment.properties"
I don't understand the deal of java.lang.NoClassDefFoundError. The jar are present and linked by -cp option
Do you have any idea (and solution), please?
You cannot combine -jar and -cp arguments on the command line. If the java command sees -jar it treats everything after the jarfile name as application arguments, AND it ignores any earlier classpath arguments.
You have two choices:
Use -cp, include the main JAR in the classpath, and put the full class name for the main class on the command line.
Use -jar, and add a "Class-Path" attribute to the main JAR's manifest file listing all of the dependencies.
References:
The java command page - explains -jar versus -cp
The JAR file specification - explains the "Class-Path" attribute
Note: since you are building the JAR file using Maven, there are other options; for example
Use the "Shade" plugin to create an executable "uber-jar" containing all of the dependencies in a single JAR.
Trying to start java program on linux but it fails to locate JSoup jar file. I have checked other questions and found on how to add libraries while compiling and while trying to run it but I am not sure if I am doing it correctly because it still fails to load the library....
I enter the following commands:
root#vps5441:/var/www/var/www/TimetableLoader# javac -cp /var/www/var/www/TimetableLoader/jsoup-1.8.1.jar:/var/www/var/www/TimetableLoader/mysql-connector-java-5.0.8/mysql-connector-java-5.0.8-bin.jar. TimetableLoader.java
root#vps5441:/var/www/var/www/TimetableLoader# java -cp /var/www/var/www/TimetableLoader/jsoup-1.8.1.jar:/var/www/var/www/TimetableLoader/mysql-connector-java-5.0.8/mysql-connector-java-5.0.8-bin.jar. -classpath /var/www/var/www/TimetableLoader/ TimetableLoader
And I get the following error when the program tries to access the JSoup library.
Exception in thread "main" java.lang.NoClassDefFoundError: org/jsoup/Jsoup
at TimetableLoader.main(TimetableLoader.java:46)
Caused by: java.lang.ClassNotFoundException: org.jsoup.Jsoup
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
... 1 more
I assume jsoup-1.8.1.jar is in the current directory?
You don't generally need both -classpath and -cp. It's probably ignoring the values given by -cp as a result.
Put your own classes ahead of the 3rd-party ones.
You're already in /var/www/var/www/TimetableLoader so keep it simple:-
root#vps5441:/var/www/var/www/TimetableLoader# java -cp .:jsoup-1.8.1.jar:mysql-connector-java-5.0.8/mysql-connector-java-5.0.8-bin.jar TimetableLoader
(Best to get out of the habit of running things as "root" unless you have a genuine need, just sayin')
I'm on Mac OS X 10.9.2 (Mavericks). I have code that uses an external Java library (twitter4j). It runs fine when I run it through NetBeans. However, trying to run almost identical code in the terminal gives me errors.
My directory structure is straightforward- I have a 'src' folder with the .java file and a 'lib' folder with the external .jar files I use.
From the src folder, I call javac -cp "../lib/*" MyProgram.java which seems to work alright. Now, if I call java MyProgram, I get an exception:
Exception in thread "main" java.lang.NoClassDefFoundError: twitter4j/StreamListener
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2693)
at java.lang.Class.privateGetMethodRecursive(Class.java:3040)
at java.lang.Class.getMethod0(Class.java:3010)
at java.lang.Class.getMethod(Class.java:1776)
at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526)
Caused by: java.lang.ClassNotFoundException: twitter4j.StreamListener
at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
It seems to have trouble properly importing the external twitter4j library. What am I missing here?
These are my import statements in the code:
import twitter4j.*;, import twitter4j.conf.ConfigurationBuilder;
UPDATE: Using suggestions below, I also tried running it via java -cp "../lib/*" MyProgram which gives: "Could not find or load main class MyProgram"
You need to specify the classpath when running the program as well as when compiling it:
E.g.
java -cp "../lib/*" MyProgram
I stumbled upon a weird error while using JDBC sqlite with org.sqlite.JDBC
my code compiles and runs fine on Windows.
But when I tried moving it to Ubuntu it started showing this:
Exception in thread "main" java.lang.ClassNotFoundException: org.sqlite.JDBC
at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:259)
at mall.SQLiteJDBC.<init>(SQLiteJDBC.java:27)
at mall.AllegroReader.<init>(AllegroReader.java:33)
at mall.Mall.main(Mall.java:31)
I'm running it with java -classpath "sqlite-jdbc-3.7.2.jar" -jar Mall.jar" and java -classpath "sqlite-jdbc4-3.8.2-SNAPSHOT.jar" -jar Mall.jar
with both versions in the same directory as my jar and I've tried a dozen different options specifying classpath and it behaves exactly the same. I tried openjdk and oracle jdk.
I tried rebuilding it on Ubuntu, changing ant .xmls, changing paths, etc.
I have no idea what is going on. Pls help.
Here is what happens inside my dist directory:
work1#workwork:/var/www/mall/dist$ ls
mall.db Mall.jar Mall.jar.old sqlite-jdbc-3.8.4.3-SNAPSHOT.jar
work1#workwork:/var/www/mall/dist$ java -classpath "sqlite-jdbc-3.8.4.3-SNAPSHOT.jar:Mall.jar" Mall
Error: Could not find or load main class Mall
The classpath is ignored when you use -jar.
You have to either include the dependencies in the jar (or at least have the jar manifest point to them), or run it with -classpath sqlite.jar:Mall.jar the.main.class.
Error: Could not find or load main class Mall.main. all files are there,
my main class comes from Mall.java and is in mall package which
compiles to Mall.jar
So the correct command line is:
java -classpath "sqlite-jdbc-3.8.4.3-SNAPSHOT.jar:Mall.jar" mall.Mall
OP findings
to view the classes in jar use jar tf Mall.jar - from this I got mall/Mall.class meaning my class containing main was mall.Mall
it showed
mall/Mall.class
so I should have used mall.Mall as the class to run (instead of pulling my hair)
After spending over 6 hours total with many failed attempts at running "portable" jar package using classpath and whatnot, after having tried OneJar and jarjar to no avail (ended up with Class file too large!) I decided to write the offending piece of code in PHP.
It proved to be more portable than Java in my case.
I am trying to run the DiscardServer module of a Maven compiled program called Netty, which I have downloaded as source code. I'm using a GNU/Linux command line terminal to try and follow the instructions in the manual http://netty.io/wiki/user-guide-for-4.x.html.
I'm assuming I should run DiscardServer in directory example/src/main/java, but when I move to that directory and type
$ java -cp "~/norbert/netty-master/all/target/netty-all-5.0.0.Alpha1-SNAPSHOT.jar:~/norbert/netty-master/all/target/netty-all-5.0.0.Alpha1-SNAPSHOT-sources.jar" io.netty.example.discard.DiscardServer
the response is "Error: Could not find or load main class io.netty.example.discard.DiscardServer"
I know the class can be run from a source directory somehow, because
$ java io.netty.example.discard.DiscardServer
produces
Exception in thread "main" java.lang.NoClassDefFoundError: io/netty/channel/EventLoopGroup
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2442)
at java.lang.Class.getMethod0(Class.java:2685)
at java.lang.Class.getMethod(Class.java:1620)
at sun.launcher.LauncherHelper.getMainMethod(LauncherHelper.java:492)
at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:484)
Caused by: java.lang.ClassNotFoundException: io.netty.channel.EventLoopGroup
at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
... 6 more
Having downloaded the binary version netty-4.0.13.Final in addition, I was able to start the discard server in directory netty-4.0.13.Final/jar as follows:
$ java -cp "netty-example-4.0.13.Final.jar:netty-transport-4.0.13.Final.jar:netty-common-4.0.13.Final.jar:netty-buffer-4.0.13.Final.jar" io.netty.example.discard.DiscardServer
How can I run the DiscardServer from directory example/src/main/java or the relevant source directory, though? Thanks, any help would be appreciated.
inside the example folder, you should run:
mvn install
then
mvn exec:java -Dexec.mainClass="io.netty.example.discard.DiscardServer"