* The HTTP multipart POST method is defined in section 3.3 of * RFC1867: *
* The media-type multipart/form-data follows the rules of all multipart * MIME data streams as outlined in RFC 1521. The multipart/form-data contains * a series of parts. Each part is expected to contain a content-disposition * header where the value is "form-data" and a name attribute specifies * the field name within the form, e.g., 'content-disposition: form-data; * name="xxxxx"', where xxxxx is the field name corresponding to that field. * Field names originally in non-ASCII character sets may be encoded using * the method outlined in RFC 1522. ** *
This entity is designed to be used in conjunction with the * {@link org.apache.http.HttpRequest} to provide * multipart posts. Example usage:
*
* File f = new File("/path/fileToUpload.txt");
* HttpRequest request = new HttpRequest("http://host/some_path");
* Part[] parts = {
* new StringPart("param_name", "value"),
* new FilePart(f.getName(), f)
* };
* filePost.setEntity(
* new MultipartRequestEntity(parts, filePost.getParams())
* );
* HttpClient client = new HttpClient();
* int status = client.executeMethod(filePost);
*
*
* @since 3.0
*/
public class MultipartEntity extends AbstractHttpEntity {
private static final Log log = LogFactory.getLog(MultipartEntity.class);
/** The Content-Type for multipart/form-data. */
private static final String MULTIPART_FORM_CONTENT_TYPE = "multipart/form-data";
/**
* Sets the value to use as the multipart boundary.
* * This parameter expects a value if type {@link String}. *
*/ public static final String MULTIPART_BOUNDARY = "http.method.multipart.boundary"; /** * The pool of ASCII chars to be used for generating a multipart boundary. */ private static byte[] MULTIPART_CHARS = EncodingUtils.getAsciiBytes( "-_1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"); /** * Generates a random multipart boundary string. */ private static byte[] generateMultipartBoundary() { Random rand = new Random(); byte[] bytes = new byte[rand.nextInt(11) + 30]; // a random size from 30 to 40 for (int i = 0; i < bytes.length; i++) { bytes[i] = MULTIPART_CHARS[rand.nextInt(MULTIPART_CHARS.length)]; } return bytes; } /** The MIME parts as set by the constructor */ protected Part[] parts; private byte[] multipartBoundary; private HttpParams params; private boolean contentConsumed = false; /** * Creates a new multipart entity containing the given parts. * @param parts The parts to include. * @param params The params of the HttpMethod using this entity. */ public MultipartEntity(Part[] parts, HttpParams params) { if (parts == null) { throw new IllegalArgumentException("parts cannot be null"); } if (params == null) { throw new IllegalArgumentException("params cannot be null"); } this.parts = parts; this.params = params; } public MultipartEntity(Part[] parts) { setContentType(MULTIPART_FORM_CONTENT_TYPE); if (parts == null) { throw new IllegalArgumentException("parts cannot be null"); } this.parts = parts; this.params = null; } /** * Returns the MIME boundary string that is used to demarcate boundaries of * this part. The first call to this method will implicitly create a new * boundary string. To create a boundary string first the * HttpMethodParams.MULTIPART_BOUNDARY parameter is considered. Otherwise * a random one is generated. * * @return The boundary string of this entity in ASCII encoding. */ protected byte[] getMultipartBoundary() { if (multipartBoundary == null) { String temp = null; if (params != null) { temp = (String) params.getParameter(MULTIPART_BOUNDARY); } if (temp != null) { multipartBoundary = EncodingUtils.getAsciiBytes(temp); } else { multipartBoundary = generateMultipartBoundary(); } } return multipartBoundary; } /** * Returnstrue if all parts are repeatable, false otherwise.
*/
public boolean isRepeatable() {
for (int i = 0; i < parts.length; i++) {
if (!parts[i].isRepeatable()) {
return false;
}
}
return true;
}
/* (non-Javadoc)
*/
public void writeTo(OutputStream out) throws IOException {
Part.sendParts(out, parts, getMultipartBoundary());
}
/* (non-Javadoc)
* @see org.apache.commons.http.AbstractHttpEntity.#getContentType()
*/
@Override
public Header getContentType() {
StringBuffer buffer = new StringBuffer(MULTIPART_FORM_CONTENT_TYPE);
buffer.append("; boundary=");
buffer.append(EncodingUtils.getAsciiString(getMultipartBoundary()));
return new BasicHeader(HTTP.CONTENT_TYPE, buffer.toString());
}
/* (non-Javadoc)
*/
public long getContentLength() {
try {
return Part.getLengthOfParts(parts, getMultipartBoundary());
} catch (Exception e) {
log.error("An exception occurred while getting the length of the parts", e);
return 0;
}
}
public InputStream getContent() throws IOException, IllegalStateException {
if(!isRepeatable() && this.contentConsumed ) {
throw new IllegalStateException("Content has been consumed");
}
this.contentConsumed = true;
ByteArrayOutputStream baos = new ByteArrayOutputStream();
Part.sendParts(baos, this.parts, this.multipartBoundary);
ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
return bais;
}
public boolean isStreaming() {
return false;
}
}