For Jersey 2.x In web.xml. The <servlet-classs> and <init-param> <param-name> must match! That is, " org.glassfish.jersey.servlet.ServletContainer " must correspond to " jersey.config.server.provider.packages " Sample snippet from web.xml file .... <servlet> <servlet-name>XYZ123</servlet-name> <servlet-class> org.glassfish.jersey.servlet.ServletContainer </servlet-class> <init-param> <param-name> jersey.config.server.provider.packages </param-name> <param-value>YOU PACKAGE</param-value> </in...