- /*
- * Copyright 2002-2013 the original author or authors.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- package org.springframework.web.servlet;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
- import org.springframework.lang.Nullable;
- /**
- * MVC framework SPI, allowing parameterization of the core MVC workflow.
- *
- * <p>Interface that must be implemented for each handler type to handle a request.
- * This interface is used to allow the {@link DispatcherServlet} to be indefinitely
- * extensible. The {@code DispatcherServlet} accesses all installed handlers through
- * this interface, meaning that it does not contain code specific to any handler type.
- *
- * <p>Note that a handler can be of type {@code 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.
- *
- * <p>This interface is not intended for application developers. It is available
- * to handlers who want to develop their own web workflow.
- *
- * <p>Note: {@code HandlerAdapter} implementors may implement the {@link
- * org.springframework.core.Ordered} interface to be able to specify a sorting
- * order (and thus a priority) for getting applied by the {@code DispatcherServlet}.
- * Non-Ordered instances get treated as lowest priority.
- *
- * @author Rod Johnson
- * @author Juergen Hoeller
- * @see org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter
- * @see org.springframework.web.servlet.handler.SimpleServletHandlerAdapter
- */
- public interface HandlerAdapter {
- /**
- * Given a handler instance, return whether or not this {@code HandlerAdapter}
- * can support it. Typical HandlerAdapters will base the decision on the handler
- * type. HandlerAdapters will usually only support one handler type each.
- * <p>A typical implementation:
- * <p>{@code
- * return (handler instanceof MyHandler);
- * }
- * @param handler handler object to check
- * @return whether or not this object can use the given handler
- */
- boolean supports(Object handler);
- /**
- * Use the given handler to handle this request.
- * The workflow that is required may vary widely.
- * @param request current HTTP request
- * @param response current HTTP response
- * @param handler handler to use. This object must have previously been passed
- * to the {@code supports} method of this interface, which must have
- * returned {@code true}.
- * @throws Exception in case of errors
- * @return ModelAndView object with the name of the view and the required
- * model data, or {@code null} if the request has been handled directly
- */
- @Nullable
- ModelAndView handle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception;
- /**
- * Same contract as for HttpServlet's {@code getLastModified} method.
- * Can simply return -1 if there's no support in the handler class.
- * @param request current HTTP request
- * @param handler handler to use
- * @return the lastModified value for the given handler
- * @see javax.servlet.http.HttpServlet#getLastModified
- * @see org.springframework.web.servlet.mvc.LastModified#getLastModified
- */
- long getLastModified(HttpServletRequest request, Object handler);
- }
来源: https://www.cnblogs.com/5ishare/p/8683971.html