I have been looking around for some time now, but didn't a find way how to export a JAR (not runnable jar) that contains in it's build path the referenced libraries.
Using Eclipse, I have included the lib folder which contains the jars of the referenced libraries in the export process.
Importing that JAR to another project and calling some method results in a ClassNotFoundException.
Looking at the MANIFEST, I didn't see any reference to those jars in the classpath, though the jars are indeed included in the jar.
So my questions are:
1. Is there any way to accomplish the packaging of the non-executable JAR so it will include libraries?
2. Is there any best practice for building and deploying a jar that include other jars libraries?
I tried it too but it doesn't work for me. I added the final .jar file but it doesn't work.
So, I did a workaround.
Extract the .jar file that you want as a dependency.
Copy that content and put it all inside your .jar file.
Add your .jar file as dependency inside an eclipse project.
Run it and see if everything is ok.
Related
I have a library called Snakeyaml.jar, and I want to add it to my eclipse project, so it will be included in my jar, when I export my project. So far, I only see ways to add an "External Jar" which only adds a jar library to the buildpath, and does NOT include it in the program when being exported! How can I do it, and do I need any plugins for that? Please help!
Thanks.
Adding the jar to your build path is for compilation and runtime, but from eclipse only. A common misconception is that jar files can be added into other jar files, which will never work. What you probably want is extract your library jar into your exported jar. To achieve this:
File - Export
Expand Java node and select Runnable JAR File
In the library handling section, select Extract required libraries into generated JAR
Reference:
http://help.eclipse.org/juno/index.jsp?topic=%2Forg.eclipse.jdt.doc.user%2Freference%2Fref-export-runnable-jar.htm
While exporting you can chose the File->Export->Runnable Jar Option . Then use the selection like below screen i.e Extract required libraries into generated jar
Okay, so I understand what you are actually asking! You want the Snakeyaml.jar file inside of your exported jar file, and for your program to use its libraries.
To do so, drag and drop the Snakeyaml.jar file into your src folder in eclipse.
Then, go to build path, and instead of looking for external jars for your buildpath, choose to use the jar file that is already in your src folder in eclipse. Once you do that, you should export it and pick to "Extract required libraries into jar file" or something like that, and everything should work well! You will notice upon opening the exported jar file with a tool like Winrar, that the jar you had in your src folder is not there, but the packages of the jar are actually side by side with yours.
I made an executable jar that depends on other jars with the command prompt using the format
jar cvfm MyJarName.jar manifest.txt *.class dependentJar1.jar dependentJar2.jar
The jar was made properly and everything seemed fine... But when run, it gets runtime errors because it can't find the class files that my project refers to. Exploring the created jar, the other 2 jars that it depends on are in there just as they should be and they are listed in the manifest.mf class path, but for some reason java is dumb and doesn't actually look inside those jars.
When those 2 jars are in the same directory as the owner jar, java is able to find them and it works fine. But I don't want this; I want those jars to actually be INSIDE it. What's the deal? How can I make an executable jar with other jars inside it work?
You can use something like OneJar or jarjar (or any of several others) to pack up everything inside of a single jar.
If you're building with Maven you could use the Maven Shade Plugin.
You could use a custom classloader like JarClassLoader that will allow precisely what you want.
I don't think you could. Maybe it's somehow possible with customized classloader, but not from-the-box. Use maven shade plugin.
If you use an Ant Builder in Eclipse and put the referenced jars in a library accessible to your project, Eclipse will extract the necessary classes and include them in your distributable jar file.
I'm fairly new to Java and need to add an external Jar to the project in netbeans. I've created a library with that Jar using Tools --> Libraries, and added the library in the project Properties --> Libraries under compile, but it still returns "Package does not exist".
Any help?
What version of Netbeans are you using? Make sure your libraries are located outside of the project directory. Just making sure when you add the jar, you don't just add the folder containing them but the actual jar -right?
Try building the project to see if that helps.
Perhaps the library was created incorrectly. If the package structure in the JAR isn't correct, the class loader won't be able to find the .class file.
Open the JAR with WinZip and confirm the contents.
I created a JAR file from my java project.
Using Eclipse, I added a JAR as a referenced library in my own project.
However, now when I try to run my program's JAR using java -jar myProgram.jar, I get an exception stating that my referenced jar is not available.
So how can I create a JAR consisting a reference to a different JAR and make it work?
Right, an executable JAR cannot contain its own JAR dependencies.
You have to have the main class and classpath set in the executable JAR manifest, then package all your JAR dependencies along with the executable JAR in a relative directory structure that matches the manifest CLASSPATH. Reading this might help.
You need to use Eclipse's runnable JAR exporter. Since Eclipse 3.5 you've the following options when you rightclick project, choose Export > Runnable JAR file:
Either way, Eclipse should take care that you'll be able to run the JAR the way you want on the exported location.
See jarjar project. It is exactly what you are looking for. http://code.google.com/p/jarjar/
I have a Java application and created a JAR file and deployed it.
The App uses external JARs such as the Log4J JAR. When creating my JAR file, how do I include all external dependent JARs into my archive?
In order to get my App working, I'm having to copy the Log4J JAR into the same directory as my own JAR which kinda defeats the purpose of the jar. Wouldn't it be more elegant to have 1 single JAR file to deploy?
If you use Eclipse, You can extract all included files into one runnable jar like this:
Right click on your project name from Package Explorer and select Export.
In Export screen, select Java -> Runnable JAR file and Next.
Fill in the Runnable JAR File Spec screen and Finish.
You can choose whether to package dependency jars as individual jar files or extract them into the generated JAR.
You could use something like One-JAR to package your Java application together with its dependency into a single executable Jar file (One-JAR uses a custom classloader to make JARs nesting possible).
You have to expand the library jars into the same place where your compiled classes go, then make a jar from that. Depending on how your build process is set up, there may be multiple ways to achieve this. It's not rocket science - a jar is just a zip archive with a META-INF directory at the root level.
Keeping JAR separate is better as it is easy to upgrade only the specific JARs to its new versions without touching any other configuration. As of your issue of having to copy each file to same location as of your JAR, you can always use Java CLASSPATH and include any JAR to your application's class path.
A JAR is not itself capable of nesting other JARs, as you discovered.
Traditionally, one would distribute a ZIP archive or other installer that would unwind the application JAR (yours) as well as any support JARs in the appropriate location for classpath access. Frequently, then, the application was invoked through a script that invoked the primary JAR and created a classpath that listed the support JARs.
As other posters have noted, you have some options to create a super-JAR if that's what you want.
You can use Maven + assembly plugin (http://maven.apache.org/plugins/maven-assembly-plugin/)
BTW, probably that's not the easiest way, if you did not work with maven.