I'm trying to install the hpricot gem on my Windows machine using JRuby 1.4.0RC1. I'm trying to follow the advice to the related question (see -> Installing hpricot for JRuby).
Per the answer's advice I pulled the git head of hpricot and from it's dir ran:
jruby -S rake package_jruby
cd pkg
sudo jgem install ./hpricot-0.8.1-jruby.gem
But when I run this I get the following NoClassDefFoundError:
Exception in thread "main" java.lang.NoClassDefFoundError: org/jruby/Main
Caused by: java.lang.ClassNotFoundException: org.jruby.Main
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)
at java.lang.ClassLoader.loadClassInternal(Unknown Source)
Could not find the main class: org.jruby.Main. Program will exit.
Apparently my JRUBY_HOME\lib\jruby.jar is getting lost.
running jruby -v works fine, so I'm confused where my class path is getting messed up.
It looks like your jruby install isn't complete. Did you grab the bin or src dist? Check if lib/jruby.jar exists, make sure bin/jruby is in the same jruby location as lib/jruby.jar, and test java -jar lib/jruby.jar -e "puts 'hello'" to see if it's functional.
I suspect sudo does not inherit your environment variables. So JRUBY_HOME is gone. Try to add it to jgem profile.
I'm on Windows. I'm not sure if JRuby 1.4 drops the 'j' prefix. jgem isn't recognized, but gem is. Regardless, when I gem environment I get:
C:\tmp\hpricot>gem environment
RubyGems Environment:
- RUBYGEMS VERSION: 1.3.5
- RUBY VERSION: 1.8.7 (2009-09-30 patchlevel 174) [java]
- INSTALLATION DIRECTORY: C:/jruby-1.4.0RC1/lib/ruby/gems/1.8
- RUBY EXECUTABLE: C:/jruby-1.4.0RC1/bin/../bin/jruby.bat
- EXECUTABLE DIRECTORY: C:/jruby-1.4.0RC1/bin/../bin
- RUBYGEMS PLATFORMS:
- ruby
- universal-java-1.6
- GEM PATHS:
- C:/jruby-1.4.0RC1/lib/ruby/gems/1.8
- GEM CONFIGURATION:
- :update_sources => true
- :verbose => true
- :benchmark => false
- :backtrace => false
- :bulk_threshold => 1000
- "install" => "--env-shebang"
- "update" => "--env-shebang"
- REMOTE SOURCES:
- http://gems.rubyforge.org/
Related
I have a Java Project (an application to play connect 4) and I want to turn it into an executable file. I created this project in VsCode, and I am using the Java Language Server (see details below). I extracted the .jar file, and used Launch4J to turn it into an executable, and when I run it, I get an error message (see below).
I researched the problem, and it seems that I need to compile my code targeting Java SE 8 rather than 17 (I have 17 currently installed). Could anyone explain to me how I should do this, or is there anything else I'm doing wrong?
The project has multiple files. I'm not sure if this is relevant, but the project has no external dependencies, although it does use javax.swing, javax.sound, and java.awt (as well as java.io.File, java.io.IOException, and java.util.Random, but I'm pretty sure those are irrelevant).
I have eclipse installed if it's necessary, but I only installed it today, and have no experience using it at all. The JDK I am using is (I believe) version 1.8.0_321. (At least this is what I get when I type in java -version.)
The Java compiler version is javac 17.0.2
When I try to run the executable generated by Launch4J, I this is the error I get:
Exception in thread "main" java.lang.UnsupportedClassVersionError: Main has been compiled by a more recent version of the Java Runtime (class file version 61.65535), this version of the Java Runtime only recognizes class file versions up to 52.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
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)
at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)
And the popup error:
Java Virtual Machine Launcher
Error: A JNI error has occurred, please check your installation and try again.
Here are the Settings I used in Launch4J:
Output File: C:\Users\username\OneDrive\Coding\Java Connect 4 v.2\Connect 4.exe
Jar: C:\Users\username\OneDrive\Coding\Java\Java Connect 4 v.2\Java Connect 4 v.2.jar
Don't wrap the jar, launch only: NOT ticked
Wrapper Manifest: none
Change dir: .
Command Line args: none
Process priority: Normal
Both Options NOT ticked
Min JRE version: 1.2.0, Prefer public JRE, but use JDK runtime if newer
Max JRE version: none, First 64-bit, then 32-bit. (This was the default.)
All other settings are default.
Download the latest Java JDK version as .exe file (“x64 Installer”) and install by clicking on the .jar file.
Now the server should start again
#Holger has answered this question. The answer to the problem was to ship a custom JRE image with the application with the help of JLink. That way it can be used regardless of the local version of JRE.
I wrote a simple multiplayer JAVA app that can connect to MySQL using JDBC driver.
I ended up packing it up in .jar file. When I was testing on my local machine MacOS, it was fine. (I don't exactly remember all the steps to set up JDBC driver, because it was year ago when I wrote this app). The app at this time connects to an external database on another server (I didn't change that because it had no problems). It would be another error if it was a problem with the remote database.
Now, when I need to put it on production on Windows Server 2003, I keep getting the standard error :
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
And I don't get it, because I think I've done the steps right:
0. Installed Java
1. downloaded this: http://dev.mysql.com/downloads/connector/j/
2. added it to the same folder where the app.jar is
3. wrote in cmd: set CLASSPATH =.;C:\Documents and Settings\Administrator\Desktop\tvplan_exchange\mysql-connector-java-5.1.28-bin.jar
4. tested the variable: echo %CLASSPATH% and it showed the same path
5. runned the app: java -jar app.jar
6. got the error:
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
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)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Unknown Source)
at svagers.Db.connect(Db.java:21)
at svagers.Server.main(Server.java:58)
MYSQL ERRORcom.mysql.jdbc.Driver
Well, for those who think that using app like this is a security error - no worries, that is not a problem, I just need it to be running not to consider risks :)
This is the environment:
OS: Windows Server 2003 (Standard Edition, Service Pack 2)
Java: 1.7.0_45 (SE Runtime Environment
I was going to say "run the app with java -cp %CLASSPATH% -jar app.jar" but then remembered you can't have both: you use either -jar or -cp. See this answer.
First off. I am a newbie and green with respect to Java programming.
I created a Java Eclipse "SWT" "Application Window" on a Eclipse Kepler 4.3.1 (32-bit) running WindowBuilder and SWT (swt.jar). The design view is a composite.
The java application runs fine from Eclipse. I simply press the play button and presto.
Problem:
Issuing
java -cp . PkgNetAccelerator32.netAcceleratorApp
yields the following error message:
Exception in thread "main" java.lang.NoClassDefFoundError: org/eclipse/swt/widgets/Composite
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Unknown Source)
at java.lang.Class.getMethod0(Unknown Source)
at java.lang.Class.getMethod(Unknown Source)
at sun.launcher.LauncherHelper.getMainMethod(Unknown Source)
at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)
Caused by: java.lang.ClassNotFoundException: org.eclipse.swt.widgets.Composite
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)
... 6 more
I was doing some research and several posts on other issues suggested that the cure is to create a manifest. I saw an article that said something like:
Select the src folder, right click and select export, then Java, then JAR file, specify Manifest.jar and a path on the folder, make sure the "Generate the manifest file" is selected, and press finish.
I created the manifest file and tried launching it with the following command line:
java -jar ../Manifest.jar -cp . PkgNetAccelerator32.netAcceleratorApp
That yielded the same error message above.
I saw another article that said that one should add in the swt.jar file, but that is taken care of by the manifest. No? Specifying "swt.jar" instead of the manifest that I created resulted in an error message:
no main manifest attribute, in ../swt.jar
That error message makes sense.
I am at a loss. How do I run the java application?
I am testing on my Windows 7 Professional 64-bit desktop, but I need to run on CENTOS too. That should be no problem, as I assume whatever the fix on Windows is, will work on CENTOS.
UPDATE:
I placed the two lib files in a /lib folder to match the answer given. I then issued the following command line and got the following error message.
C:\SoftDev\Projects\NetAccelerator\JavaWorkspace\NetAccelerator32>java -cp "bin/*;lib/*" PkgNetAccelerator32.netAcceleratorApp
Exception in thread "main" java.lang.UnsatisfiedLinkError: Cannot load 32-bit SWT libraries on 64-bit JVM
at org.eclipse.swt.internal.Library.loadLibrary(Unknown Source)
at org.eclipse.swt.internal.Library.loadLibrary(Unknown Source)
at org.eclipse.swt.internal.C.<clinit>(Unknown Source)
at org.eclipse.swt.widgets.Display.<clinit>(Unknown Source)
at PkgNetAccelerator32.netAcceleratorApp.open(netAcceleratorApp.java:43)
at PkgNetAccelerator32.netAcceleratorApp.main(netAcceleratorApp.java:33)
I found the following article, which produces a command line that works, just that is not reasonable for sending. I much rather use the answer.
Lets assume you have a eclipse project structure similar to this:
Workspace
-> Project
-> src (source code directory)
-> bin (compiled byte code directory as JAR)
-> lib (jar directory)
-> .classpath (eclipse file)
-> .project (eclipse file)
I am assuming that you are exporting the JAR as an executable JAR.
So in order to run a class in that exported JAR with another JAR from the lib directory (swt.jar) while your working directory is the Project directory you will need to execute:
java -cp "bin/*:lib/*" PkgNetAccelerator32.netAcceleratorApp
Using wildcards requires Java 6 or later
Please note: CENTOS requires : as a path separator. Windows uses a semi-colon.
This will add your classes and the swt classes onto the classpath and run your main class PkgNetAccelerator32.netAcceleratorApp
SWT 32bit vs 64bit
You will either need to use a 32bit JVM locally or continue to use a 64bit JVM and use the 64bit version of swt; see swt on windows 64 bit. I would suggest you match your version of your local JVM (32bit or 64bit) with the version that you will be running on the CENTOS machine. You will however need a different swt jar for CENTOS.
I m trying to compile an open source software . The build works fine and results into a jar file "five-server.jar". When I try to run this file from cmd , I get these errors.
C:\Users\vickey\code\five-server\dist\main>java -jar five-server.jar
Exception in thread "main" java.lang.NoClassDefFoundError: org/eclipse/swt/SWTError
Caused by: java.lang.ClassNotFoundException: org.eclipse.swt.SWTError
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: org.devtcg.five.Main. Program will exit.
any suggestion what is wrong?
The SWT Jar files are platform dependent.
See http://www.jarfinder.com/index.php/java/info/org.eclipse.swt.SWTError
e.g. on Windows a suitable jar would be:
org.eclipse.swt.win32.win32.x86_3.1.0.jar
or on Mac OS X:
swt-macosx-3.0m7.jar
and so on.
You might run into call kinds of followup problems if you add this dependency e.g. whether you are
using 32bit or 64bit libraries.
It is too bad that these kind of dependency problems show up more often than not these days :-(
You have to set the classpath so that it includes at least the class org.eclipse.swt.SWTError
or the jar containing it:
java -classpath path/to/jar/containing/org.eclipse.swt.SWTError -jar five-server.jar
You should also set the Main-class attribute in the manifest file in the five-server.jar
Following the #Wolfgang Fahl answer, you might download the references here:
Standard Widget Toolkit » 4.3 x86
Maven reference:
https://mvnrepository.com/artifact/org.eclipse.swt.org.eclipse.swt.win32.win32.x86.4.3.swt/org.eclipse.swt.win32.win32.x86/4.3
Jar file:
http://central.maven.org/maven2/org/eclipse/swt/org/eclipse/swt/win32/win32/x86_64/4/3/swt/org.eclipse.swt.win32.win32.x86_64/4.3/org.eclipse.swt.win32.win32.x86_64-4.3.jar
Standard Widget Toolkit » 4.3 x64
Maven reference: https://mvnrepository.com/artifact/org.eclipse.swt.org.eclipse.swt.win32.win32.x86_64.4.3.swt/org.eclipse.swt.win32.win32.x86_64/4.3
Jar file:
http://central.maven.org/maven2/org/eclipse/swt/org/eclipse/swt/win32/win32/x86_64/4/3/swt/org.eclipse.swt.win32.win32.x86_64/4.3/org.eclipse.swt.win32.win32.x86_64-4.3.jar
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).