Java tutorial
/* The contents of this file are subject to the license and copyright terms * detailed in the license directory at the root of the source tree (also * available online at http://fedora-commons.org/license/). */ package fedora.server.rest; import java.io.BufferedInputStream; import java.io.InputStream; import java.util.List; import javax.servlet.http.HttpServletRequest; import javax.ws.rs.core.HttpHeaders; import javax.ws.rs.core.MediaType; import org.apache.commons.fileupload.FileItemHeaders; import org.apache.commons.fileupload.FileItemIterator; import org.apache.commons.fileupload.FileItemStream; import org.apache.commons.fileupload.servlet.ServletFileUpload; import org.apache.log4j.Logger; /** * Utility class for REST operations. * * @author Bill Branan */ public class RestUtil { protected final Logger log = Logger.getLogger(getClass()); /** * Retrieves the contents of the HTTP Request. * @return InputStream from the request */ public RequestContent getRequestContent(HttpServletRequest request, HttpHeaders headers) throws Exception { RequestContent rContent = null; // See if the request is a multi-part file upload request if (ServletFileUpload.isMultipartContent(request)) { // Create a new file upload handler ServletFileUpload upload = new ServletFileUpload(); // Parse the request, use the first available File item FileItemIterator iter = upload.getItemIterator(request); while (iter.hasNext()) { FileItemStream item = iter.next(); if (!item.isFormField()) { rContent = new RequestContent(); rContent.contentStream = item.openStream(); rContent.mimeType = item.getContentType(); FileItemHeaders itemHeaders = item.getHeaders(); if (itemHeaders != null) { String contentLength = itemHeaders.getHeader("Content-Length"); if (contentLength != null) { rContent.size = Integer.parseInt(contentLength); } } break; } } } else { // If the content stream was not been found as a multipart, // try to use the stream from the request directly if (rContent == null) { if (request.getContentLength() > 0) { rContent = new RequestContent(); rContent.contentStream = request.getInputStream(); rContent.size = request.getContentLength(); } else { String transferEncoding = request.getHeader("Transfer-Encoding"); if (transferEncoding != null && transferEncoding.contains("chunked")) { BufferedInputStream bis = new BufferedInputStream(request.getInputStream()); bis.mark(2); if (bis.read() > 0) { bis.reset(); rContent = new RequestContent(); rContent.contentStream = bis; } } } } } // Attempt to set the mime type and size if not already set if (rContent != null) { if (rContent.mimeType == null) { MediaType mediaType = headers.getMediaType(); if (mediaType != null) { rContent.mimeType = mediaType.toString(); } } if (rContent.size == 0) { List<String> lengthHeaders = headers.getRequestHeader("Content-Length"); if (lengthHeaders != null && lengthHeaders.size() > 0) { rContent.size = Integer.parseInt(lengthHeaders.get(0)); } } } return rContent; } class RequestContent { private InputStream contentStream = null; private String mimeType = null; private int size = 0; /** * @return the contentStream */ public InputStream getContentStream() { return contentStream; } /** * @return the mimeType */ public String getMimeType() { return mimeType; } /** * @return the size */ public int getSize() { return size; } } }