To update jars in a WAR file without new deployment, stop the running Application and find the expanded WAR file location.
Find the JAR file that contains the file [plugin.xml, MANIFEST.MF for example]. To see the Structure of the JAR files and the files that it contains, type
unzip -l jarfilename.jar
You are likely to get output of the format:
Archive: jarfilename.jar
Length Date Time Name
--------- ---------- ----- ----
0 2013-02-20 13:35 META-INF/
868 2013-02-20 13:35 META-INF/MANIFEST.MF
1476 2013-02-20 13:26 plugin.xml
To view the content of an file type:
unzip -p jarfilename.jar plugin.xml
or the content of a file that is placed in a folder:
unzip -p jarfilename.jar META-INF/MANIFEST.MF
Now that the file to be edited is found, make a copy of it by typing the following:
mkdir META-INF
unzip -p jarfilename.jar META-INF/MANIFEST.MF > META-INF/MANIFEST.MF
nano META-INF/MANIFEST.MF
Edit the MANIFEST.MF file, and save it to the disk. Now to update the file in the jar file, type the following lines:
zip -u jarfilename.jar META-INF/MANIFEST.MF
All zip and unzip operations can be piped out to an file that can be examined at later time.
And don't forget to clean up by removing your working files and directories. In this case:
rm -rf META-INF