java - can anybody explain me difference between class level controller and method level controller..?

Question

I am new to spring framework....while searching on google..I found few examples which has @RequestMapping annoted at the class level and few examples showing it at menthod level

When to use class level RequestMapping and menthod level RequestMapping annotation...can anybody explain me difference between class level RequestMapping and method level RequestMapping ..??

so I am little bit confused about their application at :

a) Class level

b) Method level

Also I found some @Requestmapping with type :GET/Post,whereas some examples doesn't have type parameter.

Which approach is better ..??

Is newer versions(>Spring 2.5) don't need parameter type for request mapping ???

Answer 1

A controller must be marked as @Controller at the class level. The @RequestMapping annotation can be applied at both class and method level. If it is, method annotations will be interpreted as relative URLs (relative to the class-level URL). However, method level annotations must be present, otherwise the method won't be mapped.

In annotations, parameters can be marked as optional with default values. The method parameter is such a case: it defaults to GET, but can be explicitly set to POST or something else.

See:

• @RequestMapping
• 16.3 Implementing Controllers