The workspace exited with unsaved changes in the previous session; refreshing workspace to recover changes

The issue is resolved by removing the .snap file present under directory

workspace\.metadata\.plugins\org.eclipse.core.resources

Useful tcpdump commands

All traffic on a port

 $ sudo tcpdump -s0 -A "tcp port 4080 and (((ip[2:2] - ((ip[0]&0xf)<<2)) - ((tcp[12]&0xf0)>>2)) != 0)"

All HTTP GET traffic to/fro of a machine

 $ sudo tcpdump -s0 -A "src testmachine.com or dst testmachine.com and (((ip[2:2] - ((ip[0]&0xf)<<2)) - ((tcp[12]&0xf0)>>2)) != 0)" | grep -A 10 GET

Skip the Test goal during maven install

$ mvn clean install -Dmaven.test.skip=true

Displaying maven Effective POM command

$ mvn help:effective-pom

Listing the contents of war file

jar -tvf foo.war

Eclipse shows error Icons even though Maven clean install is successful

Sometimes Eclipse will show errors in your project even if maven clean install was successful. To fix these, go to Project -> Clean… and clean all projects(source here).