For anyone else who went through this problem -
I used below link to rectify the above problem based on last error.
Code changes I did in my pom file.
<dependency>
<groupId>com.atlassian.jira</groupId>
<artifactId>jira-core</artifactId>
<version>${jira.version}</version>
<scope>provided</scope>
<exclusions>
<exclusion>
<groupId>com.atlassian</groupId>
<artifactId>atlassian-logging</artifactId>
</exclusion>
<exclusion>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.sweble.wikitext</groupId>
<artifactId>swc-engine</artifactId>
<scope>compile</scope>
<exclusions>
<exclusion>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
</exclusion>
</exclusions>
</dependency>
The problem was of duplicate log4j jar being present on the class path. I removed log4j from jira-core and swc-engine just to be safe. The only log4j present on class path is from jira-api.