soap-ui - soap and rest testing system
sonar-cube - platform to manage code quality
spring-pool
jbehave - behavior java testing framework based on junit
selenium - tool for testing websites by browser
Java Flight Recorder and Java Mission Control - tool chain to continuously collect low level and detailed runtime information.
jsoup - html parser
lowagie - pdf creator
sql2o - small jdbc lib
jcommander - parse cmd
j2html - create hmtl by java code
lombok - generate java code via annotation
