Struts2.2.1 (namespace of the package, that is, the namespace of the package)

1. About the namespace of a package ):

(1) If no parameter is found, go to the invalid parameter to locate the action. If no value is found, the action will be taken;

(2) If the parameter value is found, but this action is not available in the parameter value, it is recommended that you find the parameter value by default, if this action is found, the operation cannot be found. If this action is left blank, the operation is directly executed;

(3) All the names of packages that do not have the namespace specification configured are invalid by default.