flycheck-java is on-the-fly java syntax flycheck checker using Eclipse's batch compiler.

flycheck-java can figure out project structure/layout from Eclipse project files(.project,.classpath), otherwise it assumes standard java project structure.

This checker is meant to be used as auxiliary tool together with external build system (ide, mvm, ant, etc).

flycheck-java-ecj-jar-path option has to configured to point to ECJ jar file, you can customize it using `M-x customize-variable' or programmatically:

(add-hook 'java-mode-hook
          (lambda () (setq flycheck-java-ecj-jar-path "/path/to/ecj-4.2.jar")))