所有已知实现类:
AbstractHandlerMethodAdapter, HandlerFunctionAdapter, HttpRequestHandlerAdapter, RequestMappingHandlerAdapter, SimpleControllerHandlerAdapter, SimpleServletHandlerAdapter
```
public interface HandlerAdapter
```
MVC framework SPI, allowing parameterization of the core MVC workflow.
Interface that must be implemented for each handler type to handle a request. This interface is used to allow the DispatcherServlet to be indefinitely extensible. The DispatcherServlet accesses all installed handlers through this interface, meaning that it does not contain code specific to any handler type.
Note that a handler can be of type Object. This is to enable handlers from other frameworks to be integrated with this framework without custom coding, as well as to allow for annotation-driven handler objects that do not obey any specific Java interface.
This interface is not intended for application developers. It is available to handlers who want to develop their own web workflow.
Note: HandlerAdapter implementors may implement the Ordered interface to be able to specify a sorting order (and thus a priority) for getting applied by the DispatcherServlet. Non-Ordered instances get treated as lowest priority.
作者:
Rod Johnson, Juergen Hoeller
另请参阅:
SimpleControllerHandlerAdapter, SimpleServletHandlerAdapter

方法概要

所有方法实例方法抽象方法
修饰符和类型	方法	说明
`long`	`getLastModified(HttpServletRequest request, Object handler)`	Same contract as for HttpServlet's `getLastModified` method.
`ModelAndView`	`handle(HttpServletRequest request, HttpServletResponse response, Object handler)`	Use the given handler to handle this request.
`boolean`	`supports(Object handler)`	Given a handler instance, return whether or not this `HandlerAdapter` can support it.

- 方法详细资料
  - supports
```
boolean supports(Object handler)
```
    Given a handler instance, return whether or not this HandlerAdapter can support it. Typical HandlerAdapters will base the decision on the handler type. HandlerAdapters will usually only support one handler type each.
    A typical implementation:
    return (handler instanceof MyHandler);
    参数:
    handler - the handler object to check
    返回:
    whether or not this object can use the given handler
  - handle
```
@Nullable
ModelAndView handle(HttpServletRequest request,
                    HttpServletResponse response,
                    Object handler)
             throws Exception
```
    Use the given handler to handle this request. The workflow that is required may vary widely.
    参数:
    request - current HTTP request
    response - current HTTP response
    handler - the handler to use. This object must have previously been passed to the supports method of this interface, which must have returned true.
    返回:
    a ModelAndView object with the name of the view and the required model data, or null if the request has been handled directly
    抛出:
    Exception - in case of errors
  - getLastModified
```
long getLastModified(HttpServletRequest request,
                     Object handler)
```
    Same contract as for HttpServlet's getLastModified method. Can simply return -1 if there's no support in the handler class.
    参数:
    request - current HTTP request
    handler - the handler to use
    返回:
    the lastModified value for the given handler
    另请参阅:
    HttpServlet.getLastModified(javax.servlet.http.HttpServletRequest), LastModified.getLastModified(javax.servlet.http.HttpServletRequest)

接口 HandlerAdapter

方法概要

方法详细资料

supports

handle

getLastModified