org.springframework.cloud.function.web.flux.request.FluxHandlerMethodArgumentResolver.java Source code

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Here is the source code for org.springframework.cloud.function.web.flux.request.FluxHandlerMethodArgumentResolver.java

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/*
 * Copyright 2016-2017 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.cloud.function.web.flux.request;

import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import javax.servlet.http.HttpServletRequest;

import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;

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

import org.springframework.cloud.function.context.FunctionInspector;
import org.springframework.cloud.function.web.flux.constants.WebRequestConstants;
import org.springframework.core.MethodParameter;
import org.springframework.core.Ordered;
import org.springframework.http.MediaType;
import org.springframework.util.StreamUtils;
import org.springframework.web.bind.support.WebDataBinderFactory;
import org.springframework.web.context.request.NativeWebRequest;
import org.springframework.web.method.support.HandlerMethodArgumentResolver;
import org.springframework.web.method.support.ModelAndViewContainer;
import org.springframework.web.util.ContentCachingRequestWrapper;

/**
 * Converter for request bodies of type <code>Flux<String></code>.
 * 
 * @author Dave Syer
 *
 */
public class FluxHandlerMethodArgumentResolver implements HandlerMethodArgumentResolver, Ordered {

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

    private final ObjectMapper mapper;

    private FunctionInspector inspector;

    public FluxHandlerMethodArgumentResolver(FunctionInspector inspector, ObjectMapper mapper) {
        this.inspector = inspector;
        this.mapper = mapper;
    }

    @Override
    public int getOrder() {
        return Ordered.HIGHEST_PRECEDENCE;
    }

    @Override
    public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer,
            NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {
        Object handler = webRequest.getAttribute(WebRequestConstants.HANDLER, NativeWebRequest.SCOPE_REQUEST);
        Class<?> type = inspector.getInputType(inspector.getName(handler));
        if (type == null) {
            type = Object.class;
        }
        List<Object> body;
        ContentCachingRequestWrapper nativeRequest = new ContentCachingRequestWrapper(
                webRequest.getNativeRequest(HttpServletRequest.class));
        if (logger.isDebugEnabled()) {
            logger.debug("Resolving request body into type: " + type);
        }
        if (isPlainText(webRequest) && CharSequence.class.isAssignableFrom(type)) {
            body = Arrays
                    .asList(StreamUtils.copyToString(nativeRequest.getInputStream(), Charset.forName("UTF-8")));
        } else {
            try {
                body = mapper.readValue(nativeRequest.getInputStream(),
                        mapper.getTypeFactory().constructCollectionLikeType(ArrayList.class, type));
            } catch (JsonMappingException e) {
                nativeRequest.setAttribute(WebRequestConstants.INPUT_SINGLE, true);
                body = Arrays.asList(mapper.readValue(nativeRequest.getContentAsByteArray(), type));
            }
        }
        return new FluxRequest<Object>(body);
    }

    private boolean isPlainText(NativeWebRequest webRequest) {
        String value = webRequest.getHeader("Content-Type");
        if (value != null) {
            return MediaType.valueOf(value).isCompatibleWith(MediaType.TEXT_PLAIN);
        }
        return false;
    }

    @Override
    public boolean supportsParameter(MethodParameter parameter) {
        return FluxRequest.class.isAssignableFrom(parameter.getParameterType());
    }

}