org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter Maven / Gradle / Ivy
/*
* Copyright 2002-2018 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
*
* https://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.mvc.method;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.core.Ordered;
import org.springframework.lang.Nullable;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerAdapter;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.support.WebContentGenerator;
/**
* Abstract base class for {@link HandlerAdapter} implementations that support
* handlers of type {@link HandlerMethod}.
*
* @author Arjen Poutsma
* @since 3.1
*/
public abstract class AbstractHandlerMethodAdapter extends WebContentGenerator implements HandlerAdapter, Ordered {
private int order = Ordered.LOWEST_PRECEDENCE;
public AbstractHandlerMethodAdapter() {
// no restriction of HTTP methods by default
super(false);
}
/**
* Specify the order value for this HandlerAdapter bean.
* The default value is {@code Ordered.LOWEST_PRECEDENCE}, meaning non-ordered.
* @see org.springframework.core.Ordered#getOrder()
*/
public void setOrder(int order) {
this.order = order;
}
@Override
public int getOrder() {
return this.order;
}
/**
* This implementation expects the handler to be an {@link HandlerMethod}.
* @param handler the handler instance to check
* @return whether or not this adapter can adapt the given handler
*/
@Override
public final boolean supports(Object handler) {
return (handler instanceof HandlerMethod && supportsInternal((HandlerMethod) handler));
}
/**
* Given a handler method, return whether or not this adapter can support it.
* @param handlerMethod the handler method to check
* @return whether or not this adapter can adapt the given method
*/
protected abstract boolean supportsInternal(HandlerMethod handlerMethod);
/**
* This implementation expects the handler to be an {@link HandlerMethod}.
*/
@Override
@Nullable
public final ModelAndView handle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws Exception {
return handleInternal(request, response, (HandlerMethod) handler);
}
/**
* Use the given handler method to handle the request.
* @param request current HTTP request
* @param response current HTTP response
* @param handlerMethod handler method to use. This object must have previously been passed to the
* {@link #supportsInternal(HandlerMethod)} this interface, which must have returned {@code true}.
* @return a ModelAndView object with the name of the view and the required model data,
* or {@code null} if the request has been handled directly
* @throws Exception in case of errors
*/
@Nullable
protected abstract ModelAndView handleInternal(HttpServletRequest request,
HttpServletResponse response, HandlerMethod handlerMethod) throws Exception;
/**
* This implementation expects the handler to be an {@link HandlerMethod}.
*/
@Override
public final long getLastModified(HttpServletRequest request, Object handler) {
return getLastModifiedInternal(request, (HandlerMethod) handler);
}
/**
* Same contract as for {@link javax.servlet.http.HttpServlet#getLastModified(HttpServletRequest)}.
* @param request current HTTP request
* @param handlerMethod handler method to use
* @return the lastModified value for the given handler
*/
protected abstract long getLastModifiedInternal(HttpServletRequest request, HandlerMethod handlerMethod);
}