org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdviceChain.java Source code

Introduction

Here is the source code for org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdviceChain.java

Source

/*
 * Copyright 2002-2014 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.mvc.method.annotation;

import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.core.MethodParameter;
import org.springframework.http.MediaType;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.util.CollectionUtils;
import org.springframework.web.method.ControllerAdviceBean;

/**
 * Invokes a a list of {@link ResponseBodyAdvice} beans.
 *
 * @author Rossen Stoyanchev
 * @since 4.1
 */
class ResponseBodyAdviceChain {

    private static final Log logger = LogFactory.getLog(ResponseBodyAdviceChain.class);

    private final List<Object> advice;

    public ResponseBodyAdviceChain(List<Object> advice) {
        this.advice = advice;
    }

    public boolean hasAdvice() {
        return !CollectionUtils.isEmpty(this.advice);
    }

    @SuppressWarnings("unchecked")
    public <T> T invoke(T body, MethodParameter returnType, MediaType selectedContentType,
            Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request,
            ServerHttpResponse response) {

        if (this.advice != null) {
            if (logger.isDebugEnabled()) {
                logger.debug("Invoking ResponseBodyAdvice chain for body=" + body);
            }
            for (Object advice : this.advice) {
                if (advice instanceof ControllerAdviceBean) {
                    ControllerAdviceBean adviceBean = (ControllerAdviceBean) advice;
                    if (!adviceBean.isApplicableToBeanType(returnType.getContainingClass())) {
                        continue;
                    }
                    advice = adviceBean.resolveBean();
                }
                if (advice instanceof ResponseBodyAdvice) {
                    ResponseBodyAdvice<T> typedAdvice = (ResponseBodyAdvice<T>) advice;
                    if (typedAdvice.supports(returnType, selectedConverterType)) {
                        body = typedAdvice.beforeBodyWrite(body, returnType, selectedContentType,
                                selectedConverterType, request, response);
                    }
                } else {
                    throw new IllegalStateException("Expected ResponseBodyAdvice: " + advice);
                }
            }
            if (logger.isDebugEnabled()) {
                logger.debug("After ResponseBodyAdvice chain body=" + body);
            }
        }
        return body;
    }

}