I made a simple Swing application with some database connectivity, using Notepad++ and executing it from the command prompt. It was executing perfectly.
Then I copied all of the code to Netbeans and tried to build to main project, in order to package my application as a .jar file.
A .jar file was created successfully, but when I tried to run it, it did not execute properly. For example, I had a button in my application that displays all records present in the database. It worked when I executed from the command prompt, but when the .jar file was executed, there was no response.
Hard to tell without seeing some code or error/exception stack traces. The most typical cause for problems of this kind are incomplete classpaths. Maybe your database driver class is missing on the classpath.
Some things you might check:
Do you get some sort of error?
Is the jar executable? If yes - that's the case when you start the application with something like java -jar path/to/myjar.jar - the classpath must be specified in the jar files Manifest, any -cp value is simply ignored.
Looking at your last comment, I'm pretty sure, that this is a classpath problem. The database driver usually resides in a different jar file and if the classpath entry in your manifest.mf file is blank, then the driver can't be loaded. This should result in an exception but maybe this is catched somewhere.
Solution #1 - edit the manifest.mf file and add all required libraries according to this tutorial:
Class-Path: jar1-name jar2-name directory-name/jar3-name
Solution #2 - don't start the application with the -jar option but use the standard way:
java -cp yourLib.jar;database-driver.jar your.application.Main
(all library entries have to be given with a correct relative or absolute file path)
just copy the database driver into C:\Program Files\Java\jre7\lib\ext and then run the jar file.
Related
I'm having big problems running my java api war file from the command line after ive packaged it with maven.
I'm trying to run it using the following command from the target folder where my war file is located.
java -cp silverkissen.war se/consys/silverkissen/heroku/Main
And alot of other variations but i just get
Error: Can't find or load main class se/consys/silverkissen/heroku/Main
My war file lies in path ..\Silverkissen-API\target\silverkissen.war
My heroku main class lies in path ..\Silverkissen-API\target\classes\se\consys\silverkissen\heroku\Main.class
Thankful for any help.
The main issue is most likely because the class files isn't incorporated into the silverkissen.war file. Meaning there is no Main function in the war file itself. Or that the entry function is some where else.
Or that it's packaged in some mysterious way that is beyond my understanding that's specific to maven, heroku etc.
But assuming you're standing in the project root structure, one level before the target folder usually where you'd normally have src, target, pom.xml and system.properties. I'd try running the following:
java -cp target/classes:target/dependency/* se.consys.silverkissen.heroku.Main
And if you're on Windows that'd be:
java -cp target\classes;target\dependency\* se.consys.silverkissen.heroku.Main
That aught to do it. This will execute your project with class-path's in the runtime. Assuming my limited knowledge of Java is correct.
Someone with more experience can probably explain in detail why this would work.
Open command prompt in the location where your jar/war located
And then run below command
java -jar silverkissen.war
It looks like this is a common problem, but none of the previous posts seem to address my issue.
I believe I've narrowed it down to one problem. Any application that uses an InputStream will not open, but all my other applications run fine.
The application runs fine in Eclipse, but the window won't even open when I try to run the jar file.
Task manager shows it pop up for about a second or two, and then disappears.
I have tried all three options for the Library handling upon exporting and none of them fix the issue.
Can anyone explain this?
Run it from the command line. This will allow you to see the exception that's thrown that's preventing your program from progressing.
java -jar YourJar.jar
I know I'm late, but I want to prevent people having to search hours for the same Error I just did. In Eclipse the path-String isn't case-sensitive. In the exported Runnable Jar File it is. So make sure all the pathsnames have the capital letters in the right positions, or to be save don't have capital letters at all.
Setup Your Manifest
If I had to guess, your manifest doesn't contain your main class OR the classpath is not defined.
Main-Class: https://docs.oracle.com/javase/tutorial/deployment/jar/appman.html
Class-Path: https://docs.oracle.com/javase/tutorial/deployment/jar/downman.html
If you're using a build tool like maven, it needs to be configured to add these properties: https://maven.apache.org/shared/maven-archiver/examples/classpath.html
Execute Your Jar
There are two ways to run an executable jar. As an executable jar you need to define the Main-Class and Class-Path in your manifest:
java -jar YourJar.jar
You can also skip setting up your manifest and define your classpath and main class through the JVM's parameters.
java -cp=${PATH_TO_JAR} main.package.MainClass
I have been doing a coding exercise inside the IntelliJ IDEA Community Edition 14 IDE, using OpenJDK.
The project is split over 4 .java files all in the same package.
My end goal is to run this in the terminal/bash (I use System.console().readLine() which doesnt play nicely in the IDE's console).
I've tried navigating to the directory where these 4 files reside (they all reside in the same dir) and tried:
javac -classpath . BibliotecaApp.java Book.java BookManager.java LibraryDB.java
This creates 4 corresponding .class files fine.
The Main is in bibliotecaApp.java/class, so I try run it by:
java BibliotecaApp
But I get the error
Exception in thread "main" java.lang.NoClassDefFoundError: BibliotecaApp (wrong name: com/twu/biblioteca/BibliotecaApp)
Plus about 13 lines of specifics.
Now googling this error seems to be a class path problem, and this is where I get stuck.
From places I've read, usingecho $PATH gives me:
/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games
This is still from the directory of the .java files above.
That path means nothing to me. I have no idea what it is or what it does, or what even a classpath is! Theres alot of resources out there on setting a classpath, but they aren’t helping me because I don't know what it's meant for.
That was a dead end for me. I tried to create a .jar instead using IDEA's Build Artifacts as seen HERE. It created a .jar file but when I navigate to that directory and try run it via:
java -jar biblioteca_jar
I get
Error: Invalid or corrupt jarfile biblioteca_jar
Another issue is that in the file explorer, the file actually comes out as biblioteca.jar, but ls on that dir shows biblioteca_jar. Is that normal?
The code is on my GitHub if that helps anything
https://github.com/botagar/twu-biblioteca-JohnGeddes
Based on your compiler step, change this
java BibliotecaApp
to
java -cp . BibliotecaApp
Which will add the current directory to the classpath for the java runtime environment. See also the Oracle Technote Setting the Class Path.
A jar file is a kind of zip, and should have a .jar extension. So this
java -jar biblioteca_jar
should probably be
java -jar biblioteca.jar
And you can check if the file is valid with any zip archive reader. Including jar itself,
jar tvvf biblioteca.jar
Edit
Based on your comments below,
cd ~/Documents/ThoughtWorks Uni/TWU_Biblioteca-master/src/
and then
java -cp . com.twu.biblioteca.BibliotecaApp
I wrote an application which starts by reading a configuration (.ini) file and accordingly parses some xml files within a particular folder.
Everything works perfectly when I build and run my application in NetBeans. Now I wanted to run my application through command line (because that's actual requirement of my project), so I am executing the .jar file created by Netbeans to run my application.
I am executing the application as such: java -jar Application.jar.
The issue is when I run this command on command line, the application seems to not be able to find the configuration file which is in the root folder of the project. Its really odd because NetBeans runs it perfectly.
I believe the reason I am getting this exception is because to run the .jar file I am changing my directory to dist and then running the java -jar command and therefore the file is not being found . But then how do I get around this.
Any help is appreciated. Thank you
Sorry got it figured out. I am executing jar file from the root but adding the source in the command as well.
Sorry, you can close this thread.
I had this problem till I installed JRE and did NOT use stand alone.
I've looked through many of the existing threads about this error, but still no luck. I'm not even trying to package a jar or use any third-party packaging tools. I'm simply running from within Eclipse (works great) and then trying to run the exact same app from the command line, in the same location it's built to (getting this error). My goal is to be able to zip up the bin folder and send it off to be run by someone else via a command line script. Some details:
It's a command-line app and I'm using the commons-lang-2.4.jar for string utilities. That is the file that cannot be located (specificaly "java.lang.NoClassDefFoundError: org/apache/commons/lang/StringEscapeUtils")
I have that jar in my lib folder and have added it to my build path in Eclipse via right-click "Build Path -> Add to Build Path"
The .classpath file looks correct and contains the reference to the jar, but I assume that file is only used by Eclipse (contains this line: <classpathentry kind="lib" path="lib/commons-lang-2.4.jar"/>)
Could this be related to the Eclipse working directory setting? I have some internal template files that I created that are under src/templates, and the only way I can seem to get those to be seen is by setting the project working directory to AppName/src. Maybe I should be putting those somewhere else?
Let me know if any additional info would help. Surely this is something simple, but I've wasted too much time on it at this point. This is reminding me why I originally left Java back in '05 or so...
A NoClassDefFoundError basically means that the class was there in the classpath during compiletime, but it is missing in the classpath during runtime.
In your case, when executing using java.exe from commandline, you need to specify the classpath in the -cp or -classpath argument. Or if it is a JAR file, then you need to specify it in the class-path entry of its MANIFEST.MF file.
The value of the argument/entry can be either absolute or relative file system paths to a folder containing all .class files or to an individual .jar file. You can separate paths using a semicolon ;. When a path contains spaces, you need to wrap the particular path with doublequotes ". Example:
java -cp .;c:/path/to/file.jar;"c:/spacy path/to/classes" mypackage.MyClass
To save the effort of typing and editing the argument in commandline everytime, use a .bat file.
Edit: I should have realized that you're using an Unix based operating system. The above examples are Windows-targeted. In the case of Unix like platforms you can follow the same rules, but you need to separate the paths using a colon : and instead of an eventual batch file, use a .sh file.
java -cp .:/path/to/file.jar:"/spacy path/to/classes" mypackage.MyClass
Are you specifying the classpath to java on the command line?
$ java -cp lib/commons-lang-2.4.jar your.main.Class
The classpath setting you are setting in Eclispe are only for the IDE and do not affect how you application is run outside the IDE. Even if you use the Eclipse Functionality to export your application as an executable jar file there is no out of the box way to package all the jars your application depends on.
If you have packaged you application into a jar file called myapp.jar then running a command like below will run the application with the jar you depend on, if you have more than one just add them separted by ; on Windows or : on Unix:
java -jar myapp.jar -cp .;c:/pathtolibs/commons-lang-2.4.jar
If you are just running the classes directly then either run the folder containing your .class files will also need to be on the path (though I assume it already is since you are able to run the program and get errors).
Consider File -> Export -> Runnable jar to create a jar file which can be invoked directly with
java -jar yourProgram.jar
There are several variants depending on your needs.
Eclipse does not move any of the jars in your classpath into the bin folder of your project. You need to copy the util jar into the bin folder. If you move it to the root of the bin folder, you might be able to get away without any classpath entries but it's not the recommended solution. See #BalusC's answer for good coverage of that.
Eclipse doesn't build executable java classes by default. Don't ask me why, but it probably has something to do with using their own tools.jar (somewhere in plugins/org.eclipse.core ?) so that Eclipse can run without a JDK.
You can usually go to your project bin directory and do:
java -cp . MyClass
But if you have external jars, Eclipse handles those internally in another weird way, so you'll need to add those too.
make sure your jar commons-lang-2.4.jar in classpath and not redudance.
I ever add jar file to my classpath, and have 2 file jar in my classpath. After I delete it, work smooth