I've a java script who's running by several user and working very well.
Today, I asked another user to try the script on his desktop and he's getting a ClassNotFoundException... despite the script is perfectly the same as mine (and jar locations is also the same)
Here's the command tu launch the JAR :
java -cp .;customname.jar;libs/* my.package.MyMainClass
And I also tried to add every jar in the libs folder separately :
java -cp .;customname.jar;libs/lib.jar;libs/lib2.jar;libs/lib3.jar my.package.MyMainClass
And here's the error message the user is getting :
Error: Could not find or load main class ch.vaudoise.hp.services.listener.AutoSysReorder
I checked the JAVA configuration and try to set him the same java version on "Path" environment variable. Same error.
As there's 6 user who can run the script and only one who's getting an error I'm sure it's a configuration issue. But what ? Classpath seems to be OK...
Many thanks for any help..
First things first: You must start by finding where is the conflicting class. If you don't know it, you may find it in two alternative ways:
Programatically: Code this class and execute it with the same classpath (on an environment that does not suffer the problem):
public static void main(String[] args)
{
System.out.println(ch.vaudoise.hp.services.listener.AutoSysReorder.class. getResource("/ch/vaudoise/hp/services/listener/AutoSysReorder.class"));
}
Manually, one by one: Open a command shell and execute:
javap -cp . ch.vaudoise.hp.services.listener.AutoSysReorder
javap -cp customname.jar ch.vaudoise.hp.services.listener.AutoSysReorder
javap -cp libs/lib.jar ch.vaudoise.hp.services.listener.AutoSysReorder
javap -cp libs/lib2.jar ch.vaudoise.hp.services.listener.AutoSysReorder
...
Try one by one every entry in the classpath until the class is found.
Once found the location of the class, open a shell in the conflicting PC and make sure that path is accessible:
dir lib\conflicting-library-or-directory
Also, repeat the javap test:
javap -cp conflicting-library-or-directory ch.vaudoise.hp.services.listener.AutoSysReorder
After this tests, you should have more clues to find the cause of the problem.
Take a look at ClassNotFoundException despite class in the classpath
You are also including meta character (*) in your classpath.
Try without that as suggested in the link.
Also some times copy pasting to command line , may get some characters copied differently.
I cannot add comment as of now : So , editing this answer.
| Java path is not an issue.
Try the following step by step :
- find which jar the class that is being not found is in .
- include only that jar as cp.
- include only that class and try
java -jar that.jar
Also try this once
java -cp "*;"
If you still got issue , probably the jar does not contain the class (You can open jar and check).
And you say script - is this single command which is failing or is it part of script ?. Using java -jar -cp , usually ignores cp.
When I try to use the EvoSuite testing tool from the command line, I get the following error:
Fatal crash on main EvoSuite process. Class using seed 1428172877144. Configuration id : null
java.lang.RunTimeExceptionConfiguration:Did not manage to automatically find tools.jar. Use –Dtools_jar_location = <path> properly
at org.evosuite.runtime.agent.ToolsJarLocator.getLoaderForToolsJar<ToolsJarLocator.java:71> ~[evosuite-0.1.1.jar:na]
at org.evosuite.Evosuite.parseCommandLine<Evosuite.java:152> ~[evosuite-0.1.1.jar:na]
at org.evosuite.Evosuite.main<Evosuite.java:304> ~[evosuite-0.1.1.jar:na]
Could someone help me with this?
Make sure you use your JDK to run Evosuite, not the JRE. That may mean either going into the JDK /bin dir and running from there or fully quantifying the executable java binary file when you run (JDK..../bin/java.exe on windows for example).
Copy the tools.jar from JDK to your JRE lib folder...it worked for me..The problem, its not able to find the tools.jar.
As pointed out by Makoto, you need to use a -D option. Note: no space between variable name and assigned value, ie -Dx=v is OK, whereas -Dx = v is wrong. So:
java -jar evosuite-0.1.1.jar -Dtools_jar_location="C:\Program Files\Java\jdk1.7.0_75\lib"
This question already has answers here:
What does "Could not find or load main class" mean?
(61 answers)
Closed 2 years ago.
I am running a simple "HelloWorld" Program. I get this error in the command prompt:
Could not find or load main class HelloWorld.
I have set the CLASSPATH and PATH variable in the system. In the cmd prompt, I am running from the directory where I have saved HelloWorld program. I can see the class name and the file name are same and also .class file created in the same directory. What else could be the problem?
My sample program looks like this:
package org.tij.exercises;
public class HelloWorld {
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("Hello World!!");
}
}
When the Main class is inside a package then you need to run it as follows :
java <packageName>.<MainClassName>
In your case you should run the program as follows :
java org.tij.exercises.HelloWorld
What's your CLASSPATH value?
It may look like this:
.;%JAVA_HOME%\lib\dt.jar;%JAVA_HOME%\lib\tools.jar
I guess your value does not contain this .;.
So, ADD IT .
When you done , restart CMD
That may works.
For example the file HelloWorld.java is in path: D:\myjavatest\org\yz\test and its package is: org.yz.test.
Now, you're in path D:\myjavatest\ on the CMD line.
Type this to compile it:
javac org/yz/test/HelloWorld.java
Then, type this to run it:
java org.yz.test.HelloWorld
You may get what you want.
I removed bin from the CLASSPATH. I found out that I was executing the java command from the directory where the HelloWorld.java is located, i.e.:
C:\Users\xyz\Documents\Java\javastudy\src\org\tij\exercises>java HelloWorld
So I moved back to the main directory and executed:
java org.tij.exercises.HelloWorld
and it worked, i.e.:
C:\Users\xyz\Documents\Java\javastudy\src>java org.tij.exercises.HelloWorld
Hello World!!
Since you're running it from command prompt, you need to make sure your classpath is correct. If you set it already, you need to restart your terminal to re-load your system variables.
If -classpath and -cp are not used and CLASSPATH is not set, the current directory is used (.), however when running .class files, you need to be in the folder which consist Java package name folders.
So having the .class file in ./target/classes/com/foo/app/App.class, you've the following possibilities:
java -cp target/classes com.foo.app.App
CLASSPATH=target/classes java com.foo.app.App
cd target/classes && java com.foo.app.App
You can check your classpath, by printing CLASSPATH variable:
Linux: echo $CLASSPATH
Windows: echo %CLASSPATH%
which has entries separated by :.
See also: How do I run Java .class files?
I had the same problem, mine was a little different though I did not have a package name. My problem was the Class Path for example:
C:\Java Example>java -cp . HelloWorld
The -cp option for Java and from what I can tell from my experience (not much) but I encountered the error about 20 times trying different methods and until I declared the class Path I was receiving the same error. Vishrant was correct in stating that . represents current directory.
If you need more information about the java options enter java -? or java -help I think the options are not optional.
I just did some more research I found a website that goes into detail about CLASSPATH. The CLASSPATH must be set as an environment variable; to the current directory <.>. You can set it from the command line in windows:
// Set CLASSPATH to the current directory '.'
prompt> set CLASSPATH=.
When you add a new environment setting you need to reboot before enabling the variable. But from the command prompt you can set it. It also can be set like I mentioned at the beginning. For more info, and if your using a different OS, check: Environment Variables.
One reason for this error might be
Could not find or load main class <class name>
Maybe you use your class name as different name and save the class name with another name you can save a java source file name by another name than class name. For example:
class A{
public static void main(String args[]) {
System.out.println("Hello world");
}
}
you can save as Hello.java but,
To Compile : javac Hello.java
This will auto generate A.class file at same location.
Now To Run : java A
Execute your Java program using java -d . HelloWorld command.
This command works when you have declared package.
. represent current directory/.
I had a similar problem when running java on win10
instead of
$ java ./hello
Error: Could not find or load main class ..hello
Run
$ java hello
Hello, World
I was getting the exact same error for forgetting to remove the .class extension when running the JAVA class. So instead of this:
java myClass.class
One should do this:
java myClass
I used IntelliJ to create my .jar, which included some unpacked jars from my libraries. One of these other jars had some signed stuff in the MANIFEST which prevented the .jar from being loaded. No warnings, or anything, just didn't work. Could not find or load main class
Removing the unpacked jar which contained the manifest fixed it.
I faced the same problem and tried everything mentioned here.
The thing was I didn't refresh my project in eclipse after class creation .
And once I refreshed it things worked as expected.
faced the same problem. solved by following these steps
go to directory containing the package 'org.tij.exercises' (e.g: in eclipse it may be your src folder)
use java org.tij.exercises.HelloWorld
For a lot of us, at least for me, I think the class path hierarchy is not intuitive since I'm working inside a directory structure and it feels like that ought to be it.
Java is looking at the name of the class based on it's package path, not just the file path.
It doesn't matter if:
i'm in the local directory ./packagefoo/MainClass, or
a directory up ./packagefoo/, or
one down ./packagefoo/MainClass/foo.
The command "java packagefoo.MainClass" is running off the root %CLASSPATH% which means something significant to Java. Then from there it traverses package names, not path names like us lay coders would expect.
So if my CLASSPATH is set to %CWD%/, then "java packagefoo.MainClass" will work.
If I set the CLASSPATH to %CWD%/packagefoo/ then packagefoo.MainClass can't be found.
Always "java MainClass" means nothing, if it is a member of "package", until I rip out the java code "package packagefoo;" and move the Class File up a directory.
In fact if I change "package packagefoo;" to "package foopackage;" I have to create a subfolder under CLASSPATH/foopackage or foopackage.MainClass stops working again.
To make matters worse, Between PATH, CLASSPATH, JAVAHOME, for Windows, JDeveloper, Oracle Database, and every user name it was installed under, I think a coder trying to just get something up fast ends up brute forcing path variables and structure until something works without understanding what it means.
at least i did.
Create a folder org/tij/exercises and then move HelloWorld.java file. Then run below command
javac -cp . org/tij/exercises/HelloWorld.java
AND
java -cp . org/tij/exercises/HelloWorld
I was facing similar issue but it was due to space character in my file directory where I kept my java class.
Scenario given below along with solution:
public class Sample{
public static void main(String[] args) {
System.out.println("Hello world, Java");
}
}
My Sample.java class was kept at Dir "D:\Java Programs\Sample.java"[NOTE: Package statement not present in java class].
In command prompt, changed directory to "D:\Java Programs\", my programmed compiled but failed to run with error "Could not find or load main class"
After all the possible solutions over SOF(nothing worked), I realized may b space causing me this issue.
Surprisingly removal of folder name space char['Java Programs' -> 'JavaPrograms'], my program executed successfully. Hope it helps
I'm trying to run Java program using cmd.
When I compile that file using
javac helloworld.java
It works perfectly but when I try to run that file using
java helloworld
I get an error:
couldn't find or load main class.
even though my I put my javac path in class path in system variables and javac working correctly.
After searching on how I can fix it I found that I can use
java -cp . helloworld
because it let you to find .class file.
and it works but I know that I can run java program without this -cp so what this for and how I can run my program without it?
-cp specifies the Java classpath for the JRE you are attempting to start. Look for an environment variable CLASSPATH and add '.'.
-cp is used to set the classpath for the jar file, this flag is same as importing a jar file to eclipse and then use it.
If you want to run without this flag, use should set the classpath first beforing running.
export CLASSPATH=path/to/your/jarfile.jar
If you already have some classpath set
export CLASSPATH=$CLASSPATH:path/to/your/jarfile.jar
If you want to include current directory
export CLASSPATH=$CLASSPATH:path/to/your/jarfile.jar:.
As other have mentioned, you can set the CLASSPATH. However, a much better approach is to bundle the .class files in a JAR ans user java -jar nameofthejar.jar.
I'm trying to get my Apache Lucene demo to work and I'm down to setting the classpath in this tutorial http://lucene.apache.org/java/2_3_2/demo.html
I've hunted the web and these wer the 2 solutions I found to set CLASSPATH:
CLASSPATH=${CLASSPATH}:/Users/philhunter/Desktop/COM562\ Project/lucene-3.0.3/lucene-core-3.0.3.jar
and
setenv CLASSPATH ${CLASSPATH}:/Users/philhunter/Desktop/COM562\ Project/lucene-3.0.3/lucene-core-3.0.3.jar
The second one brings up a error
-bash: setenv: command not found
The first one seemed to accept ok but wen i tried the next step in the tutorial i got an error. The next step was to run the following:
Phil-hunters-MacBook:webapps philhunter$ java org.apache.lucene.demo.IndexFiles /Users/philhunter/Desktop/COM562\ Project/lucene-3.0.3/src
which gave me the error:
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/lucene/demo/IndexFiles
This leads me to believe my CLASSPATHS didnt set correctly. Would I be right in assuming this? I have tried other tutorials and demos and see to get this same error quite a bit. Im new to Lucene and relatively new to mac and Unix shell scripting. Anyone know if I am setting the CLASSPATH correctly and if thats the cause of the errors?
in the terminal type
$ vim ~/.bash_profile
edit the file and add one line:
export CLASSPATH=${CLASSPATH}:/usr/local/lucene-3.6.2/lucene-core-3.6.2.jar:/usr/local/lucene-3.6.2/contrib/demo/lucene-demo-3.6.2.jar;
make sure to change the path of yours.
In your way you lose to add lucene-demo-3.0.3.jar in your classpath.
When you set an environment variable like CLASSPATH then by default it only applies to the current process (i.e. the shell process itself) - it isn't available to the java process you launch in the next line. In order to make it available to other processes you need to "export" the variable. In this case you can use something like:
export CLASSPATH=${CLASSPATH}:/Users/philhunter/Desktop/COM562\ Project/lucene-3.0.3/lucene-core-3.0.3.jar
This basically says "set the CLASSPATH variable to its current value plus the location of the lucene jar, and make the new variable available to any processes launched from this shell".
However, with java the usual way of setting the classpath is to do it as part of the java command itself, using the -classpath or -cp options. In your case it would look something like:
Phil-hunters-MacBook:webapps philhunter$ java -cp /Users/philhunter/Desktop/COM562\ Project/lucene-3.0.3/lucene-core-3.0.3.jar org.apache.lucene.demo.IndexFiles /Users/philhunter/Desktop/COM562\ Project/lucene-3.0.3/src
As an aside, the error you see when using the setenv line is because setenv is the command used in the C shell to set environment variables, but the default Mac shell (and the shell you're using) is bash which doesn't recognise setenv and lets you know it doesn't recognise it with the error message: -bash: setenv: command not found.
i create a .bash_profile file in my home directory and do things like
export GRAILS_HOME=/usr/share/grails
...
export PATH=${GRAILS_HOME}/bin:${GROOVY_HOME}/bin:/usr/local/mysql-5.1.45-osx10.6-x86_64/bin:${PATH}
you can work of that to set the classpath -- these examples show how to declare an environment variable and how to use the variable in other variables.