Adding jars to classpath

Kali84 · 03-15-2016, 09:17 AM

Hi folks, I'm looking to use a script to add multiple jar libraries to CLASSPATH for a java project. Easy for me with a bat in Windows but I can't seem to get it to work on my amazon instance.

This is my home directory

ec2-user> test1.jar test2.jar poi-3.14 jar.sh

Test1.jar works fine and has no library calls from poi. Test2.jar gives a no main exception. poi-3.14 is the directory containing the poi jar files. jar.sh is my script as printed below. I've tried a few different things now such as changing the jar to tar in the file endings. Adding the . , adding the\ after the : and nothing seems to be working. I'm getting the same error each time.

This is my script

Code:

#!/bin/bash
export CLASSPATH=/home/ec2-user/poi-3.14/poi-3.14-20160307.jar:\
/home/ec2-user/poi-3.14/poi-scratchpad-3.14-20160307.jar:\
/home/ec2-user/poi-3.14/poi-ooxml-schemas-3.14-20160307.jar:\
/home/ec2-user/poi-3.14/poi-examples-3.14-20160307.jar:\
/home/ec2-user/poi-3.14/poi-excelant-3.14-20160307.jar:\
/home/ec2-user/poi-3.14/poi-ooxml-3.14-20160307.jar:\.

Am I doing something silly here?

pan64 · 03-15-2016, 09:48 AM

What is the error message you got?
Probably you need another construct, without \<newline>:

Code:

D=/home/ec2-user/poi-3.14
CLASSPATH=$D/poi-3.14-20160307.jar:$D/poi-scratchpad-3.14-20160307.jar:poi-ooxml-schemas-3.14-20160307.jar
CLASSPATH=$CLASSPATH:$D/poi-examples-3.14-20160307.jar:$D/poi-excelant-3.14-20160307.jar:poi-ooxml-3.14-20160307.jar
export CLASSPATH

Kali84 · 03-15-2016, 10:23 AM

Quote:

Originally Posted by pan64

What is the error message you got?
Probably you need another construct, without \<newline>:

Code:

D=/home/ec2-user/poi-3.14
CLASSPATH=$D/poi-3.14-20160307.jar:$D/poi-scratchpad-3.14-20160307.jar:poi-ooxml-schemas-3.14-20160307.jar
CLASSPATH=$CLASSPATH:$D/poi-examples-3.14-20160307.jar:$D/poi-excelant-3.14-20160307.jar:poi-ooxml-3.14-20160307.jar
export CLASSPATH

Thanks for the help pan64, I finally have it working. It took me way longer than it should have.

Kali84 · 03-15-2016, 10:45 AM

Quote:

Originally Posted by Kali84

Thanks for the help pan64, I finally have it working. It took me way longer than it should have.

Seems I spoke too soon. The programme is running now, which is more than before, but when the library call executes I'm getting a NoDefClassFoundError org/apache/poi/poifs/filesystem/POIFSFileSystem error.

Also, when I run 'echo $CLASSPATH' I get a blank return.

pan64 · 03-15-2016, 11:50 AM

so you did not set it properly. I do not know what did you do, so hard to give a hint...

Kali84 · 03-15-2016, 11:57 AM

Quote:

Originally Posted by pan64

so you did not set it properly. I do not know what did you do, so hard to give a hint...

I uploaded the jar.sh file to my Linux server. Ran chmod +x jar.sh, then ./jar.sh. I then ran my test.jar (java -jar test.jar) which has the library calls but on executing the library call the error I mentioned occurred. Am I not running the script right. Should the classpath not print out when I echo $CLASSPATH?

Also I added in exec java -jar test2.jar. This starts my programme running. But when I have exec java -cp -jar test2.jar, I receive a could not loaf or find main class test2.jar error.

pan64 · 03-16-2016, 02:39 AM

was this CLASSPATH setting made in that jar.sh? ./jar.sh will start a new shell and CLASSPATH will be set inside that shell. The shell will be finished when the script completed and all the settings will be lost. The parent shell (your current one) will never know what's happened there.
If you want to set the current environment use:
source jar.sh
or
put java -cp -jar ... into that jar.sh

sundialsvcs · 03-16-2016, 07:51 AM

"Ninety-nine jars of code on the wall ... ninety-nine jars of code ..."

When building long and complicated path-strings, I use a series of export-commands, each of which adds one new file-name to the string, and each of which fits neatly on one (short ...) line in the file. The script is executed as part of the bash-profile. It can also be executed by the scripts which invoke the Java environment to do things.

From time to time I've also encountered scripts that read a list of library-names from a file and assemble these into an environment variable.