How to rebuild old plugin for Jira 7?

[invinci]

HI,

I have a plugin which is custom built for Jira 6.x and I want to make the same plugin to work for Jira 7.x. What are the ways to do this?

Say the only resource I have is the .jar plugin file which has all the information about classes, dependencies, related to old version of jira. 

If I make changes to the pom.xml file and upload the addon to jira, will it work with Jira 7.x?

Error from Log:

/rest/issueNav/1/issueTable [c.atlassian.ozymandias.SafePluginPointAccess] A LinkageError indicates that plugin code was compiled with outdated versions.  Unable to run plugin code because of 'java.lang.AbstractMethodError - null'.

How can I fix this issue?

[Nic Brough -Adaptavist- · Accepted solution]

Nope, you need the source code.  The .jar is compiled code which is referring to librarys that are no longer valid or available.  The pom.xml is an instruction on what to do during compilation and later, changing it in the jar is not going to recompile the code.

You could try a decompiler, but I would look for the code first.

[invinci]

Hey Nick,

I used the decompiler to see through the jar file and found out that there a lot of files insidie it. Unfortunately, I do not posses the source code for this custom plugin, so does that mean there is no way of making this plugin work for new version of Jira?

[Nic Brough -Adaptavist-]

Probably not, unless you're willing to go over every class in it, decompile them and then rewrite the code and make it compatible.