application_controller.rb

# ActiveRecord 404
rescue_from ActiveRecord::RecordNotFound do |e|
  ...
end

# Catch all unhandled exceptions
rescue_from Exception do |e|
  ...
end

api docs for rescue_from说：

Handlers are inherited. They are searched from right to left,from
bottom to top,and up the hierarchy. The handler of the first class
for which exception.is_a?(klass) holds true is the one invoked,if
any.

我解释了关于陈述错误.如何获得我正在寻找的行为？