org.camunda.bpm.engine.rest.mapper.MultipartPayloadProvider.java Source code

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Here is the source code for org.camunda.bpm.engine.rest.mapper.MultipartPayloadProvider.java

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/* 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.camunda.bpm.engine.rest.mapper;

import org.apache.commons.fileupload.FileItemIterator;
import org.apache.commons.fileupload.FileItemStream;
import org.apache.commons.fileupload.FileUpload;
import org.apache.commons.fileupload.RequestContext;
import org.camunda.bpm.engine.rest.exception.RestException;
import org.camunda.bpm.engine.rest.mapper.MultipartFormData.FormPart;

import javax.ws.rs.Consumes;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.core.Response.Status;
import javax.ws.rs.ext.MessageBodyReader;
import javax.ws.rs.ext.Provider;
import java.io.IOException;
import java.io.InputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;

/**
* <p>Provides a {@link MessageBodyReader} for {@link MultipartFormData}. This allows writing resources which
* consume {@link MediaType#MULTIPART_FORM_DATA} which is parsed into a {@link MultipartFormData} object:</p>
*
* <pre>
* {@literal @}POST
* {@literal @}Consumes(MediaType.MULTIPART_FORM_DATA)
* void handleMultipartPost(MultipartFormData multipartFormData);
* </pre>
*
* <p>The implementation used apache commons fileupload in order to parse the request and populate an instance of
* {@link MultipartFormData}.</p>
*
* @author Daniel Meyer
*/
@Provider
@Consumes(MediaType.MULTIPART_FORM_DATA)
public class MultipartPayloadProvider implements MessageBodyReader<MultipartFormData> {

    public static final String TYPE_NAME = "multipart";
    public static final String SUB_TYPE_NAME = "form-data";

    public boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) {
        return TYPE_NAME.equals(mediaType.getType().toLowerCase())
                && SUB_TYPE_NAME.equals(mediaType.getSubtype().toLowerCase());
    }

    public MultipartFormData readFrom(Class<MultipartFormData> type, Type genericType, Annotation[] annotations,
            MediaType mediaType, MultivaluedMap<String, String> httpHeaders, InputStream entityStream)
            throws IOException, WebApplicationException {

        final MultipartFormData multipartFormData = createMultipartFormDataInstance();
        final FileUpload fileUpload = createFileUploadInstance();

        String contentType = httpHeaders.getFirst("content-type");
        RestMultipartRequestContext requestContext = createRequestContext(entityStream, contentType);

        // parse the request (populates the multipartFormData)
        parseRequest(multipartFormData, fileUpload, requestContext);

        return multipartFormData;

    }

    protected FileUpload createFileUploadInstance() {
        return new FileUpload();
    }

    protected MultipartFormData createMultipartFormDataInstance() {
        return new MultipartFormData();
    }

    protected void parseRequest(MultipartFormData multipartFormData, FileUpload fileUpload,
            RestMultipartRequestContext requestContext) {
        try {
            FileItemIterator itemIterator = fileUpload.getItemIterator(requestContext);
            while (itemIterator.hasNext()) {
                FileItemStream stream = itemIterator.next();
                multipartFormData.addPart(new FormPart(stream));
            }
        } catch (Exception e) {
            throw new RestException(Status.BAD_REQUEST, e, "multipart/form-data cannot be processed");

        }
    }

    protected RestMultipartRequestContext createRequestContext(InputStream entityStream, String contentType) {
        return new RestMultipartRequestContext(entityStream, contentType);
    }

    /**
     * Exposes the REST request to commons fileupload
     *
     */
    static class RestMultipartRequestContext implements RequestContext {

        protected InputStream inputStream;
        protected String contentType;

        public RestMultipartRequestContext(InputStream inputStream, String contentType) {
            this.inputStream = inputStream;
            this.contentType = contentType;
        }

        public String getCharacterEncoding() {
            return null;
        }

        public String getContentType() {
            return contentType;
        }

        public int getContentLength() {
            return -1;
        }

        public InputStream getInputStream() throws IOException {
            return inputStream;
        }

    }

}