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| Re: Java Questions [message #1177349 is a reply to message #1177154] |
Fri, 08 November 2013 18:25   |
Eclipse User |
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On 11/8/2013 2:18 PM, John Mising name wrote:
> For several years, I've built a project and run it using simple batch
> file when I'm not in Eclipse, as follows:
> "c:\program files\Java\jdk1.6.0_18\bin\javac" srcdir\*.java
> "c:\program files\Java\jdk1.6.0_18\bin\java" srcdir/packagename
> And there is the appropriate package statement in the main class's .java
> definition.
> pause
>
> The above batch file works fine. The program compiles and runs no
> problem. The program depends on lots
> of Java .jar files. They are found no problem.
>
> Here's my problem: Someone recently split the project up into just a
> small number of .jar files, including
> one for the main program. But if I type something like java -jar
> packagename.jar, the program will no longer
> find some of the same Java .jar files (even though it has the same
> dependencies on them). Does anyone know
> why it's so much easier for the java command to find dependent .jar
> files so easily if the main class is
> in a .class file but it's much harder when the main class is now in a
> .jar file? When I execute a .class file, I have no problem. But now
> that someone put the class in a .jar file, it no longer finds the other
> jars.
> Admittedly, I'm using a later version of the Java JDK but that shouldn't
> matter. The person uses an
> XML script as a manifest but I can read the dependencies in that script
> and I see what he's doing but
> I don't want to run it over the Internet when I have the .jar files
> locally. How can I take a .jar
> file that's the main class and simply list the other jars? MUST I
> create a manifest or can I simply
> list them somehow on the command line of the java.exe command. I'm
> pretty much clueless but I know
> if I list them somehow that the program will NOT get
> java.lang.NoClassDefFoundError which is what
> it gets now. I'm not real worried about this, I'd just like to
> understand something that would
> seem to me to be pretty simple. Why does creating a .jar file upset the
> whole process so much?
> Should it upset the process so much?
Running an application using java -jar is quite different from running a
..class file with respect to the classpath used.
I suggest that you go through the Oracle tutorial for packaging programs
in jars.
http://docs.oracle.com/javase/tutorial/deployment/jar/index.html
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| Re: Java Questions [message #1190484 is a reply to message #1177349] |
Sat, 16 November 2013 11:29 |
| Eclipse User |
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The main jre/lib/ext directory is a good spot to put my extra jars such as 3D lib jars. But, I would rather not take copies of my 3D libs and put them there (from their original install directory under 1.5.2 dir). What should I say on the command-line to replace this - something like -jar pathtojar/thelib.jar? or just the thelib or something?
I would rather leave my 3D jars in their original directories. This is not a big deal as my programs compile and run fine but as you say, the tutorial would help.
Also, I normally use the command-line to build my java projects but sometimes I DO use Eclipse - particularly when I have a lot of debugging. Is there a way I can get at the internal command that is synthesized by Eclipse to do the build? I would learn more if I knew where that command was kept?
I did not find the tutorial much help. I just want a simple explanation of what to say on the command-line. I am not looking for a way to package things. My program compiles and runs fine - but I have to copy the 3D jars to the jre/lib/ext directory - I just want to know what to add to the command-line to reference this jar during a build by the javac command so that I don't have to copy my 3D jars (the 3 or 4 of them) to that directory. Do I just say -jar and then a "well-formed" path to the jars? Perhaps I need to list each jar individually.
Here's all the flags for javac:
>javac -help
Usage: javac <options> <source files>
where possible options include:
-g Generate all debugging info
-g:none Generate no debugging info
-g:{lines,vars,source} Generate only some debugging info
-nowarn Generate no warnings
-verbose Output messages about what the compiler is doing
-deprecation Output source locations where deprecated APIs are used
-classpath <path> Specify where to find user class files
-cp <path> Specify where to find user class files
-sourcepath <path> Specify where to find input source files
-bootclasspath <path> Override location of bootstrap class files
-extdirs <dirs> Override location of installed extensions
-endorseddirs <dirs> Override location of endorsed standards path
-d <directory> Specify where to place generated class files
-encoding <encoding> Specify character encoding used by source files
-source <release> Provide source compatibility with specified release
-target <release> Generate class files for specific VM version
-version Version information
-help Print a synopsis of standard options
-X Print a synopsis of nonstandard options
-J<flag> Pass <flag> directly to the runtime system
Should I use the -extdirs or -endorsedirs? I would think that -classpath, -cp, and
-sourcepath would not help since I'm only talking about jars.
Should I override the installed extensions and just copy everything to a new more
centralized directory? By everything, I mean stuff like rt.jar and so forth. I don't know how many I need to copy - I may need to get at the dependencies using some command.
Any help appreciated.
Thank you. 
[Updated on: Sat, 16 November 2013 11:42] by Moderator |
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