Hope there is a simple answer for this. We have an old SWING application that is launched from the command line. It depends on a set of libraries that are located in a folder C:\lib.
What is the correct syntax from loading C:\lib to the classpath. Something like this?
java -jar myapplicaiton.jar -CLASSPATH="C:\lib"
This seems to result in an Exception relating to being unable to see the libraries
Related
I'm new to Java11/all the overcomplicated module stuff.
The Problem
So I exported my Java11/JavaFX11 program from Eclipse as a Runnable JAR. If I click the JAR, it runs perfectly fine (Eclipse includes all of the module settings and JavaFX itself automatically in the runnable JAR). However, if I try to bundle the JAR with a JRE and run it via the command line with the following BAT file:
#ECHO OFF
%~dp0\jre\bin\java -jar javaprogram.jar
pause
I get:
Error: JavaFX runtime components are missing, and are required to run this application
Press any key to continue . . .
How can I get it to just run the JAR file like it does when I click it?
Ways I've tried to fix it
The weirdest part is, if I just use:
java -jar javaprogram.jar
Which just accesses the installed JRE, it works again. It's only when I'm directly pointing it to a JRE at a specific path that it appears to break.
Alternatively, I'd just bundle JavaFX beside the JRE, but there doesn't seem to be a way to call --module-path with a relative path (googling this nets me a bunch of entirely unrelated stuff). It seems to demand an exact path, which isn't going to work if people are downloading a zip archive and extracting it. This would be redundant though because Eclipse is already packaging JavaFX with the JAR. I don't know why it's getting confused just because I'm calling it from the command line.
The project's code
The project I'm trying to get this to work with happens to be open source, so you can check out the code for it here:
https://github.com/SkyAphid/JDialogue
The main class is JDialogueCore.
Closing
I don't want to use installers since I think that's too bloaty. I'd like to be able to deploy my software like I always have by just putting them in an archive you can extract and run.
It's difficult to simply Google the problems as well since I keep getting completely unrelated results due to the broadness of the topic. Any direction/documentation relating to this problem would be greatly appreciated.
Thank you for your time!
While Java 8, 9, and 10 allowed a JavaFX Application subclass to act as a main class for program startup, that is no longer the case as of Java 11. Placing your public static void main method in a different class and making that class the main class solves the problem. (Source: https://github.com/javafxports/openjdk-jfx/issues/236)
Your command line invocation needs to specify both the location of the JavaFX jar files, and the location of JavaFX native libraries. Normally these are the same location in the JavaFX SDK, but they must be specified in different ways: the jar files go in the classpath or module path, while the native libraries’ location must be specified in a system property:
cd /d %~dp0
jre\bin\java -cp javaprogram.jar;javafx-sdk-11\lib -Djava.library.path=javafx-sdk-11\lib com.example.MyNonApplicationClass
If you define a module-info.java in your program, your .jar is a modular .jar, and you can benefit from the additional security of modules:
cd /d %~dp0
jre\bin\java --module-path javaprogram.jar;javafx-sdk-11\lib -Djava.library.path=javafx-sdk-11\lib -m com.example.myapp/com.example.MyNonApplicationClass
If your modular .jar file has a main class defined, you can omit the class name:
cd /d %~dp0
jre\bin\java --module-path javaprogram.jar;javafx-sdk-11\lib -Djava.library.path=javafx-sdk-11\lib -m com.example.myapp
Notice that relative paths work just fine with --module-path. Relative paths use the current directory as a base. The current directory is not changed merely by putting %~dp0 in front of the invocation of Java. The current directory is a property of the command line or script actively running, and can only be changed with commands like cd or pushd.
When I run the Jar-file inside netbeans it works.
But after I clean and build it, it won't run.
It gives me an error, that the Mainclass couldn't be found.
I tried already something like:
java -cp C:\javaProjectsTests\J.jar;C:\javaProjectsTests\lib\*;. j.J
java -Djava.library.path=C:\javaProjectsTests\lib\* -jar C:\javaProjectsTests\J.jar
Maybe someone could help?
Please refer below link
Execute jar file with multiple classpath libraries from command prompt
Lod your jars to classpath and execute your class (with main method)
Thanks,
It was a syntaxerror in the path-string.
It works now, but only if the lib-folder(other jar-files) is in the same directory as the executing jar-file. Should not a problem for comandline programs, as it's possible to use a batch-file to execute from somewhere else.
However I asked me if it's possible to merge archives, as I could read on a website here ?
Uploaded a jar file from my computer to a server and tried to run it. When I run it I get java.lang.NoClassDefFoundError and it seems to be related to the twitter4j jar that my main method depends on.
However, I have this jar file in my libraries so shouldn't this be included when I build my code in to a jar? Here's a pic in case it helps.
is the error that I'm getting. (can't upload a pic just yet.
Not sure what this has to do with twitter, but anyway, the issue is that you do not have the correct class files. In other words, when you are running your fat JAR in the command prompt, you do not have any libraries exported with it (Or if you do, you don't have that specific one).
Sometimes such an error can be because there is an incorrect version of java, however that is not the case here since java has got no "twitter" packages or classes in it.
Using something like JarSplice would fix this.
Assuming you did not package the twitter4j classes inside your application jar, you need to tell Java where it can look for classes that are not inside your application jar. You typically use the classpath flag for that. In your case, it should look something like
java -cp /tmp/twitter4j.jar -jar /tmp/myapp.jar
An alternative would be to package all twitter4j's classes inside your application jar. This is called a 'fat' jar. How to make one depends on how you build your application jar.
The JAR file that you are trying to use needs to be in the classpath. This can be done by using the -cp attribute from the command line. However, when using java -jar, you cannot use the -cp attribute.
To get around this, you can do the following:
java -cp /tmp/myapp.jar;\path\to\external.jar com.example.package.MyClass
where MyClass has the main() method defined.
Alternately, you can specify jar files on the classpath using the manifest.mf file. See http://docs.oracle.com/javase/tutorial/deployment/jar/manifestindex.html for details.
I tried to run FindBugs in command line and had troubles when specifying the project to be analyzed. I understand FindBugs works on bytecode (.jar, .class), so I wrote a HelloWorld program and made sure that it had some messy code that would be detected by FindBugs.
Then I tried:
java -jar D:/findbugs-2.0.3/lib/findbugs.jar -project HelloWorld/bin
which threw an exception:
java.lang.IllegalArgumentException: Can't read project from HelloWorld/bin
at edu.umd.cs.findbugs.Project.readProject(Project.java:774)
I also tried .class and .jar files, but nothing showed up:
java -jar D:/findbugs-2.0.3/lib/findbugs.jar -project HelloWorld/bin/Main.class
java -jar D:/findbugs-2.0.3/lib/findbugs.jar -project HelloWorld.jar
I checked the FindBugs manual about the command line option "-project", it says
The project file you specify should be one that was created using the GUI interface. It will typically end in the extension .fb or .fbp
I don't understand this. Does it mean that some pre-processing is required and FindBugs cannot check arbitrary .jar or .class or project directly? How can I get this .fb or .fbp extension?
Thanks.
The procedure is described on the FindBugs website:
Make sure you download the FindBugs distribution which includes the GUI (called Swing interface).
Extract your downloaded ZIP and add its bin folder to your PATH.
Type findbugs to open the GUI, then click New Project
In the dialog:
Enter a project name, say HelloWorld.
Where it says Classpath for analysis, give it the Jar with your .class files or a directory where the .class files are (such as build/classes/main or whatever; the package structure must start in this directory).
Where it says Auxiliary classpath, list any libraries required to load your classes.
Source directories works just like Classpath for analysis, but for .java files. FindBugs uses this to show you where in the code your issues are.
You can select (cloud disabled) as bug store.
Click Analyze.
Now you can save the project configuration as a .fbp project file.
Next time, you can start the analysis by running
java -jar D:/findbugs-2.0.3/lib/findbugs.jar -project HelloWorld.fbp
If you don't want to or cannot use the GUI, you can get the text-only version by adding the -textui option as first option after findbugs.jar. Output formats and behavior are configured via additional command line options.
However, most people use FindBugs integrated with their IDEs, or as part of a build process. Neither use case should require the GUI or command line versions. Take a look at the plugins for your IDE, it may save you a lot of time and they are really easy to use.
I think I have seen this done, but am not sure where. What I want to do is to create a bat file I can package with my class files when sending to a friend to show them progress/ask advice on non programming matters. My friend is not very handy when it comes to code and doesn't like changing computer settings. Just using java myClass as a command line won't work here because although my friend does have java installed, he has not set his windows environment variables so his command prompt knows where to find java.
What kind of line would I need to add to my batch file to make it so it can compensate for problems like this?
Create a manifest file (manifest.txt):
Main-Class: com.mycompany.myapp.MyMainClass
Package your app as a jar:
jar cfm myjarfile.jar manifest.txt *.class
Create a batch file:
start myjarfile.jar
If it is about sharing and running a single java file without jar dependencies. And you are only worried about the java runtime environment setup, then you can use online java code compilers and executors. Here is one:
http://javalaunch.com/JavaLaunch.jsp
You can google for more!
Use an IDE, NetBeans or eclipse and package your files as a Jar file.. that can be executed directly and you do not need to worry about dependencies, other classes or libraries.