I have a class in java "Main.class", wrote and stored in %TEMP%. When executing the class through VB.Net Shell, eg:
Shell("cmd.exe /k java %TEMP%\Main.class")
Also when trying to execute manually through CMD: "java %TEMP%\Main.class", I am returned with:
Exception in thread "main" java.lang.NoClassDefFoundError: C:\Users\Ben\AppData\
Local\Temp\Main/class
Caused by: java.lang.ClassNotFoundException: C:\Users\Ben\AppData\Local\Temp\Mai
n.class
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
Could not find the main class: C:\Users\Ben\AppData\Local\Temp\Main.class. Prog
ram will exit.
However, when I execute Main.class manually through compile.bat - the class runs fine. What is the reasoning for this?
You need to add -classpath to it. Basically the Java interpreter does not know where to find this "Main" class.
CoolBean's solution should work. Something like
Shell("cmd.exe /k java -classpath %TEMP% Main")
Since you can (and are supposed to) omit the .class extension. And like CoolBeans said, you set the directory your class file lives in as the classpath.
While javac takes a file, java takes a Class (in other words, the name of the class after 'public class'), along with what packages it is in (if you don't have "package something;" at the top of your java file, don't worry about this), and it'll look for that class in the classpath you provide, or the current working directory.
If that does end up being the solution, give CoolBeans the accepted answer.
However, an alternative solution is to change the current working directory for Shell to %TEMP%, like:
IO.Directory.SetCurrentDirectory(Environ("TEMP"))
Shell("cmd.exe /k java Main")
Or alternatively look into the Process class, which offers more fine control over launching other programs (and with Process you can also change the directory of the program you're launching without changing the current directory of your own application).
Try this,
Shell("java.exe -cp .;" & Environment.GetEnvironmentVariable("TEMP") & " Main")
OR
Dim args As String = String.Format("-cp .;{0} {1}", Environment.GetEnvironmentVariable("TEMP"), "Main")
Dim procInfo As New ProcessStartInfo
procInfo.FileName = "java.exe"
procInfo.Arguments = args
Dim proc As New Process
proc.StartInfo = procInfo
proc.Start()
proc.WaitForExit()
Related
Hello when i am running my application from Eclipse it runs perfectly but when i export it as a runnable jar, it doesn't run.
When i try running it from cmd it gives me one of 2 errors the first errror is after i just export it with the "copy required libraries into a sub-folder":
Exception in thread "main" java.lang.UnsatisfiedLinkError: no j3dcore-ogl in java.library.path
at java.lang.ClassLoader.loadLibrary(Unknown Source)
at java.lang.Runtime.loadLibrary0(Unknown Source)
at java.lang.System.loadLibrary(Unknown Source)
at javax.media.j3d.NativePipeline$1.run(NativePipeline.java:189)
at java.security.AccessController.doPrivileged(Native Method)
at javax.media.j3d.NativePipeline.loadLibrary(NativePipeline.java:180)
at javax.media.j3d.NativePipeline.loadLibraries(NativePipeline.java:137)
at javax.media.j3d.MasterControl.loadLibraries(MasterControl.java:948)
at javax.media.j3d.VirtualUniverse.<clinit>(VirtualUniverse.java:280)
at javax.media.j3d.Canvas3D.<clinit>(Canvas3D.java:3862)
at Main.Game.<init>(Game.java:39)
at Main.Main.main(Main.java:6)
when i change the sub-folder's name from IslandDomination_lib to just lib it gives me another error:
Exception in thread "main" java.lang.NoClassDefFoundError: javax/media/j3d/Canvas3D
at Main.Main.main(Main.java:6)
Caused by: java.lang.ClassNotFoundException: javax.media.j3d.Canvas3D
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 1 more
I have tried running it several ways:
1.
java.exe -jar IslandDomination.jar
2.
java.exe -cp "lib/j3dcore.jar;lib/j3dutils.jar;lib/vecmath.jar" -jar IslandDomination.jar
3. using another java program to run it for me:
package main;
import java.io.File;
import java.io.IOException;
public class Main {
public static void main(String[] args) throws IOException, InterruptedException{
ProcessBuilder pb = new ProcessBuilder(System.getProperty("java.home")+"\\bin\\java.exe", "-cp" , "\"lib/j3dcore.jar;lib/j3dutils.jar;lib/vecmath.jar\"" , "-jar" , "IslandDomination.jar");
pb.directory(new File("./"));
Process p = pb.start();
p.waitFor();
}
}
The internal structure of my jar consists of 4 folders:
J3DBool
Main
Maths
META-INF
The folder with the required jars is in the same folder as the main jar
You use a completely obsolete version of Java3D, which is very difficult to bundle in any software as you have to set the Java library path somehow and you have to bundle both the Java libraries and the native libraries. Rather rebuild your project with Java3D 1.6.0 pre 12, it's a lot easier to use as this version relies on JOGL 2 which uses automatic native library loading and everything is packaged as JARs, there is no longer any need of modifying the library path, just take care of the classpath.
Please follow my tutorial, especially the very last section with (a lot) more information.
Finally, the obsolete version that you use isn't guaranteed to work on any recent operating systems. If it works, you'll be lucky; if it doesn't, nobody will fix it.
I think the required library file (jar file) not found in the classpath.
you need to set Library file in your class path.
step to set class path:-
MyComputer->Properties->Advanced system setting->Environment variables
find "classpath" either in user variables area or in system variables if found edit that and put all the jar file link. if not found then create new(click on new) and put all the jar link there and try to run your application
I found out how to fix my problem and it is done by simply putting the needed dll files next to the executable jar file
I'm new to JAVA and trying unable to figure out what's wrong with the project I created.
I created a JAVA project in eclipse and exported a jar (not runnable jar).
I unchecked .project and .classpath file options while exporting. Now I'm trying to run that jar and getting NoClassDefFoundError:
I'm pasting the command and the errors below:
C:\Users\Anjali>"C:\Program Files\Java\jre7\bin\java.exe" -classpath D:\Web\Hbas
eGateway\bin;C:\Users\Anjali\Downloads\Hbase\hbase-0.94.5-security.jar;C:\Users\
Anjali\Downloads\Hbase\lib\hadoop-core-1.0.4.jar;C:\Users\Anjali\Downloads\Hbase
\py4j0.7.jar -jar D:\Web\HbaseGateway\bin\HBaseGateway.jar
Exception in thread "main" java.lang.NoClassDefFoundError: py4j/GatewayServer
at hbase.gateway.HBaseGatewayEntryPoint.main(HBaseGatewayEntryPoint.java
:22)
Caused by: java.lang.ClassNotFoundException: py4j.GatewayServer
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 1 more
Now, interesting thing is I'm able to run the main class using the following command.
In the below command I removed the -jar switch and passed the main class to java.exe.
C:\Users\Anjali>"C:\Program Files\Java\jre7\bin\java.exe" -classpath D:\Web\Hbas
eGateway\bin;C:\Users\Anjali\Downloads\Hbase\hbase-0.94.5-security.jar;C:\Users\
Anjali\Downloads\Hbase\lib\hadoop-core-1.0.4.jar;C:\Users\Anjali\Downloads\Hbase
\py4j0.7.jar hbase.gateway.HBaseGatewayEntryPoint
Gateway Server Started
Why NoClassDefFoundError is being thrown? Am I missing something here?
For -jar option to work, you must add Main-class key in manifest.
Refer the java command documentation http://docs.oracle.com/javase/1.5.0/docs/tooldocs/windows/java.html
-jar option
Execute a program encapsulated in a JAR file. The first argument is the name of a JAR file instead of a startup class name.
In order for this option to work, the manifest of the JAR file must contain a line of the form Main-Class: classname. Here, classname identifies the class having the public static void main(String[] args) method that serves as your application's starting point.
When you use the -jar option, the classpath is read from the MANIFEST.mf file as well. From the docs for the -jar option:
When you use this option, the JAR file is the source of all user classes, and other user class path settings are ignored.
This means that you have to add all your dependencies in a Class-Path section of the manifest file.
I am in the folder :
/cygdrive/d/ragsxq where I have kept some simple X-Query stmts to be executed via Saxon X-Query engine...(Saxon 9.4 HE )
The following statement :
$ java -classpath /cygdrive/d/saxon/saxon9he.jar net.sf.saxon.Query -q:ragsXQuery.xq
gives :
java.lang.NoClassDefFoundError: net/sf/saxon/Query Caused by:
java.lang.ClassNotFoundException: net.sf.saxon.Query at
java.net.URLClassLoader$1.run(Unknown Source) at
java.security.AccessController.doPrivileged(Native Method) at
java.net.URLClassLoader.findClass(Unknown Source) at
java.lang.ClassLoader.loadClass(Unknown Source) at
sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at
java.lang.ClassLoader.loadClass(Unknown Source) Could not find the main class:
net.sf.saxon.Query. Program will exit. Exception in thread "main"
But the below statement works fine:
$ java -classpath ../saxon/saxon9he.jar net.sf.saxon.Query -q:ragsXQuery.xq
?!?!
Something to do with the Class-loader..?? Permmissions..?? Cygwin ? Hmmmmm...
Thanks a lot for pointing out this Cygwin behavior!
But the strange thing is, i run into this java.lang.NoClassDefFoundError (exactly the same as above) when I try to Run an Xquery via my Eclipse (Indigo) on Mac OS Lion too...via the XQDT plugin, where I have to configure the XQuery engine by providing the full-path of the saxon9he.jar & the main-class viz., net.sf.saxon.Query
Note that a similar set-up on Windows-XP works fine.
This time, I guess it could be some Classpath issue or the way Mac OS's Java treats things differently ?
I think I have faced this before. It is probably a Cygwin nuance. Just try
$ java -classpath `cygpath -m /cygdrive/d/saxon/saxon9he.jar` net.sf.saxon.Query -q:ragsXQuery.xq
Here is a possible explanation as to why:
http://cygwin.com/ml/cygwin/2008-01/msg00083.html
Below is the output from my Cygwin for an executable JAR file. I use Windows Vista 32 bit (I know, it sucks).
adarshr$ java -jar /cygdrive/d/adarshr/data/cf.jar
Error: Unable to access jarfile /cygdrive/d/adarshr/data/cf.jar
adarshr$
adarshr$ java -jar `cygpath -m /cygdrive/d/adarshr/data/cf.jar`
Usage: java -jar cf.jar SEARCH [DIRECTORY] [OPTIONS]...
Try -h or --help for more information
As you can see, the second command worked and printed a help (as expected).
I have downloaded a java developers kit for my 64bit windows 7, wrote down my code in the notepad, though the code is compiling from the command prompt and creating a .class file, but its refusing to run showing the error code:
java.lang.NoClassDefFoundError: first Caused by: java.lang.ClassNotFoundException: first
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
Could not find the main class: first. Program will exit. Exception in thread "main"
I have made sure more than once that the file name and the class name are exactly same(i have kept them smallcase 'a' just to be sure). But still no avail, could you please suggest a few solutions please.. I'm new to java i'm basically a C/C++ programmer.
A java program has this basic structure:
ClassName.java
public class ClassName
{
public static void main(String[] args)
{
}
}
try using this outline to generate your code.
compile and run with:
javac ClassName.java
java ClassName
I used to get this error when I ran a Class file.
Try doing: java NameOfClass
You don't need the .java extension when running, but you need it for compiling. That was always the problem I used to have.
Did you set your classpath?
http://download.oracle.com/javase/1.3/docs/tooldocs/win32/classpath.html
java -classpath <path> <classname>
You must provide with the code.
Anyway, from the Java Docs, class ClassNotFoundException:
Thrown when an application tries to
load in a class through its string
name using:
The forName method in class Class.
The findSystemClass method in class ClassLoader.
The loadClass method in class ClassLoader.
but no definition for the class with the specified name
could be found.
Must read link : Tip: Causes of java.lang.ClassNotFoundException
It is quite possible after compiling your code you would be writing java filename.java.
Because this sought of exception occurs then.
After compiling your program using javac filename.java use the command to start your interpreter java filename.
As you enter this command java interpreter automatically starts interpreting filename.class.
commands :
javac filename.java // to start compiling
java filename // to start interpreting
I am trying to build a simple java program which creates a db file, then a table and inserts dummy values in the table. I found this page http://www.zentus.com/sqlitejdbc/index.html and tried out the example given on the page but I am getting the following error -
Exception in thread "main" java.lang.NoClassDefFoundError: Test
Caused by: java.lang.ClassNotFoundException: Test
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
Could not find the main class: Test. Program will exit.
Well that looks like it's a matter of the classpath not being right.
My guess is that you're
If you've put something like
java -cp sqlitejdbc-v056.jar Test
then you probably just need to add the current directory to the classpath:
# Windows
java -cp sqlitejdbc.jar-v056;. Test
# Unix
java -cp sqlitejdbc.jar-v056:. Test
Having looked at that page, my guess is that you used : as the classpath separator, as shown on the page, rather than ; which you need to use if you're on Windows.
Are you sure you're building the test correctly? Here are the steps you'll need to take:
Create a file named Test.java, because it will contain the class named Test
Paste the Java code from the Getting Started section into this file and save it
Download the sqlitejdbc-v056.jar file
and put it in the same directory as the Test.java file
Use javac to compile Test.java into Test.class
Run the command from the Getting Started section
You should see:
name = Gandhi
job = politics
name = Turing
job = computers
name = Wittgenstein
job = smartypants
as output.