Upload a file through an HTTP form, via MultipartEntityBuilder, with a progress bar
android, file-upload, http
Solution
The winning code (in spectacular Java-Heresy(tm) style) is:
public static String postFile(String fileName, String userName, String password, String macAddress) throws Exception {
HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(SERVER + "uploadFile");
MultipartEntityBuilder builder = MultipartEntityBuilder.create();
builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
final File file = new File(fileName);
FileBody fb = new FileBody(file);
builder.addPart("file", fb);
builder.addTextBody("userName", userName);
builder.addTextBody("password", password);
builder.addTextBody("macAddress", macAddress);
final HttpEntity yourEntity = builder.build();
class ProgressiveEntity implements HttpEntity {
@Override
public void consumeContent() throws IOException {
yourEntity.consumeContent();
}
@Override
public InputStream getContent() throws IOException,
IllegalStateException {
return yourEntity.getContent();
}
@Override
public Header getContentEncoding() {
return yourEntity.getContentEncoding();
}
@Override
public long getContentLength() {
return yourEntity.getContentLength();
}
@Override
public Header getContentType() {
return yourEntity.getContentType();
}
@Override
public boolean isChunked() {
return yourEntity.isChunked();
}
@Override
public boolean isRepeatable() {
return yourEntity.isRepeatable();
}
@Override
public boolean isStreaming() {
return yourEntity.isStreaming();
} // CONSIDER put a _real_ delegator into here!
@Override
public void writeTo(OutputStream outstream) throws IOException {
class ProxyOutputStream extends FilterOutputStream {
/**
* @author Stephen Colebourne
*/
public ProxyOutputStream(OutputStream proxy) {
super(proxy);
}
public void write(int idx) throws IOException {
out.write(idx);
}
public void write(byte[] bts) throws IOException {
out.write(bts);
}
public void write(byte[] bts, int st, int end) throws IOException {
out.write(bts, st, end);
}
public void flush() throws IOException {
out.flush();
}
public void close() throws IOException {
out.close();
}
} // CONSIDER import this class (and risk more Jar File Hell)
class ProgressiveOutputStream extends ProxyOutputStream {
public ProgressiveOutputStream(OutputStream proxy) {
super(proxy);
}
public void write(byte[] bts, int st, int end) throws IOException {
// FIXME Put your progress bar stuff here!
out.write(bts, st, end);
}
}
yourEntity.writeTo(new ProgressiveOutputStream(outstream));
}
};
ProgressiveEntity myEntity = new ProgressiveEntity();
post.setEntity(myEntity);
HttpResponse response = client.execute(post);
return getContent(response);
}
public static String getContent(HttpResponse response) throws IOException {
BufferedReader rd = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
String body = "";
String content = "";
while ((body = rd.readLine()) != null)
{
content += body + "\n";
}
return content.trim();
}
# NOTE ADDED LATER: as this blasterpiece gets copied into various code lineages,
# The management reminds the peanut gallery that "Java-Heresy" crack was there
# for a reason, and (as commented) most of that stuff can be farmed out to off-
# the-shelf jar files and what-not. That's for the java lifers to tool up. This
# pristine hack shall remain obviousized for education, and for use in a pinch.
# What are the odds??
Problem
The short version - `org.apache...MultipartEntity` is deprecated, and its upgrade, `MultipartEntityBuilder`, appears under-represented in our online forums. Let's fix that. How does one register a callback, so my (Android) app can display a progress bar as it uploads a file? The long version - Here's the "missing dirt-simple example" of `MultipartEntityBuilder`: ``` public static void postFile(String fileName) throws Exception { // Based on: https://stackoverflow.com/questions/2017414/post-multipart-request-with-android-sdk HttpClient client = new DefaultHttpClient(); HttpPost post = new HttpPost(SERVER + "uploadFile"); MultipartEntityBuilder builder = MultipartEntityBuilder.create(); builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE); builder.addPart("file", new FileBody(new File(fileName))); builder.addTextBody("userName", userName); builder.addTextBody("password", password); builder.addTextBody("macAddress", macAddress); post.setEntity(builder.build()); HttpResponse response = client.execute(post); HttpEntity entity = response.getEntity(); // response.getStatusLine(); // CONSIDER Detect server complaints entity.consumeContent(); client.getConnectionManager().shutdown(); } // FIXME Hook up a progress bar! ``` We need to fix that `FIXME`. (An added benefit would be interruptible uploads.) But (please correct me whether or not I'm wrong), all the online examples seem to fall short. This one, http://pastebin.com/M0uNZ6SB, for example, uploads a file as a "binary/octet-stream"; not a "multipart/form-data". I require real fields. This example, File Upload with Java (with progress bar), shows how to override the `*Entity` or the `*Stream`. So maybe I can tell the `MultipartEntityBuilder` to `.create()` an overridden entity that meters its upload progress? So if I want to override something, and replace the built-in stream with a counting stream that sends a signal for every 1000 bytes, maybe I can extend the `FileBody` part, and override its `getInputStream` and/or `writeTo`. But when I try `class ProgressiveFileBody extends FileBody {...}`, I get the infamous `java.lang.NoClassDefFoundError`. So while I go spelunking around my `.jar` files, looking for the missing Def, can someone check my math, and maybe point out a simpler fix I have overlooked?