What my application is doing is creating a large csv file (its a report) and the idea is to deliver the contents of the csv file without actually saving a file for it. Here's my code
String csvData; //this is the string that contains the csv contents
byte[] csvContents = csvData.getBytes();
response.contentType = "text/csv";
response.headers.put("Content-Disposition", new Header(
"Content-Disposition", "attachment;" + "test.csv"));
response.headers.put("Cache-Control", new Header("Cache-Control",
"max-age=0"));
response.out.write(csvContents);
ok();
The csv files that are being generated are rather large and the error i am getting is
org.jboss.netty.handler.codec.frame.TooLongFrameException: An HTTP line is larger than 4096 bytes.
Whats the best way to overcome this issue?
My tech stack is java 6 with play framework 1.2.5.
Note: the origin of the response object is play.mvc.Controller.response
Please use
ServletOutputStream
like
String csvData; //this is the string that contains the csv contents
byte[] csvContents = csvData.getBytes();
ServletOutputStream sos = response.getOutputStream();
response.setContentType("text/csv");
response.setHeader("Content-Disposition", "attachment; filename=test.csv");
sos.write(csvContents);
We use this to show the results of an action directly in the browser,
window.location='data:text/csv;charset=utf8,' + encodeURIComponent(your-csv-data);
I am not sure about the out of memory error but I would at least try this:
request.format = "csv";
renderBinary(new ByteArrayInputStream(csvContents));
Apparently netty complains that the http-header is too long - maybe it somehow thinks that your file is part of the header, see also
http://lists.jboss.org/pipermail/netty-users/2010-November/003596.html
as nylund states, using renderBinary should do the trick.
We use writeChunk oursleves to output large reports on the fly, like:
Controller:
public static void getReport() {
final Report report = new Report(code, from, to );
try {
while (report.hasMoreData()) {
final String data = await(report.getData());
response.writeChunk(data);
}
} catch (final Exception e) {
final Throwable cause = e.getCause();
if (cause != null && cause.getMessage().contains("HTTP output stream closed")) {
logger.warn(e, "user cancelled download");
} else {
logger.error(e, "error retrieving data");
}
}
}
in report code
public class Report {
public Report(final String code, final Date from, final Date to) {
}
public boolean hasMoreData() {
// find out if there is more data
}
public Future<String> getData() {
final Job<String> queryJob = new Job<String>() {
#Override
public String doJobWithResult() throws Exception {
// grab data (e.g read form db) and return it
return data;
}
};
return queryJob.now();
}
}
Related
I have a function that save all the error in a errormessage list
public class Util {
private List<String> errorMessages = new ArrayList<>();
public void outputResult(String content) {
logger.error(content);
errorMessages.add(content);
}
}
and my compare function add all the error message to the list,
public void compare(Config source, Config target) {
if (source.getId() != target.getId()) {
util.outputResult("id not equal");
}
// ...
}
And in my main function, I call this compare function and want to save all the error message in a txt or some other file in my current directory
public class MyClass {
public void main() {
compare();
// writeToFile
}
}
This is what I'm doing right now, I convert ByteArrayOutputStream to a string and print it, there a txt file generated but is empty, and I don't want to a string, I want each error message in the list be printed, how can I do that?
ByteArrayOutputStream errorMessages = new ByteArrayOutputStream();
try (FileWriter w = new FileWriter(pathToReport)) {
w.write(errorMessages.toString());
}
File errorMessagesFile = new File(pathToReport);
errorMessagesFile.writeText(errorMessages.toString());
What logger library that you are using? If you use sl4j, you can couple it with log4j by configuring properly to just log the error messages into the file that you have specified in the configuration. I've done some lookup and I find this stackoverflow: where-does-the-slf4j-log-file-get-saved answer provided a template for you to follow on with this setup.
So I am using Java for my Server and Angular for the Client. I am currently working on a feature where you can select multiple files from a table and when you press on download, it generates a zip file and downloads it to your browser. As of right now, the server now creates the zip file and I can access it in the server files. All that is left to do is to make it download on the client's browser. (the zip file is deleted after the client downloads it)
After doing some research, I found out that you can use a fileOutputStream to do this. I also saw some tools like retrofit... I am using REST and this is what my code looks like. How would I achieve my goal as simply as possible?
Angular
httpGetDownloadZip(target: string[]): Observable<ServerAnswer> {
const params = new HttpParams().set('target', String(target)).set('numberOfFiles', String(target.length));
const headers = new HttpHeaders().set('token', this.tokenService.getStorageToken());
const options = {
headers,
params,
};
return this.http
.get<ServerAnswer>(this.BASE_URL + '/files/downloadZip', options)
.pipe(catchError(this.handleError<ServerAnswer>('httpGetZip')));
}
Java zipping method
public void getDownloadZip(String[] files, String folderName) throws IOException {
[...] // The method is huge but basically I generate a folder called "Download/" in the server
// Zipping the "Download/" folder
ZipUtil.pack(new File("Download"), new File("selected-files.zip"));
// what do I return ???
return;
}
Java context
server.createContext("/files/downloadZip", new HttpHandler() {
#Override
public void handle(HttpExchange exchange) throws IOException {
if (!handleTokenPreflight(exchange)) { return; }
System.out.println(exchange.getRequestURI());
Map<String, String> queryParam = parseQueryParam(exchange.getRequestURI().getQuery());
String authToken = exchange.getRequestHeaders().getFirst("token");
String target = queryParam.get("target") + ",";
String[] files = new String[Integer.parseInt(queryParam.get("numberOfFiles"))];
[...] // I process the data in this entire method and send it to the previous method that creates a zip
Controller.getDownloadZip(files, folderName);
// what do I return to download the file on the client's browser ????
return;
}
});
A possible approach to successfully download your zip file can be the described in the following paragraphs.
First, consider returning a reference to the zip file obtained as the compression result in your downloadZip method:
public File getDownloadZip(String[] files, String folderName) throws IOException {
[...] // The method is huge but basically I generate a folder called "Download/" in the server
// Zipping the "Download/" folder
File selectedFilesZipFile = new File("selected-files.zip")
ZipUtil.pack(new File("Download"), selectedFilesZipFile);
// return the zipped file obtained as result of the previous operation
return selectedFilesZipFile;
}
Now, modify your HttpHandler to perform the download:
server.createContext("/files/downloadZip", new HttpHandler() {
#Override
public void handle(HttpExchange exchange) throws IOException {
if (!handleTokenPreflight(exchange)) { return; }
System.out.println(exchange.getRequestURI());
Map<String, String> queryParam = parseQueryParam(exchange.getRequestURI().getQuery());
String authToken = exchange.getRequestHeaders().getFirst("token");
String target = queryParam.get("target") + ",";
String[] files = new String[Integer.parseInt(queryParam.get("numberOfFiles"))];
[...] // I process the data in this entire method and send it to the previous method that creates a zip
// Get a reference to the zipped file
File selectedFilesZipFile = Controller.getDownloadZip(files, folderName);
// Set the appropiate Content-Type
exchange.getResponseHeaders().set("Content-Type", "application/zip");
// Optionally, if the file is downloaded in an anchor, set the appropiate content disposition
// exchange.getResponseHeaders().add("Content-Disposition", "attachment; filename=selected-files.zip");
// Download the file. I used java.nio.Files to copy the file contents, but please, feel free
// to use other option like java.io or the Commons-IO library, for instance
exchange.sendResponseHeaders(200, selectedFilesZipFile.length());
try (OutputStream responseBody = httpExchange.getResponseBody()) {
Files.copy(selectedFilesZipFile.toPath(), responseBody);
responseBody.flush();
}
}
});
Now the problem is how to deal with the download in Angular.
As suggested in the previous code, if the resource is public or you have a way to manage your security token, including it as a parameter in the URL, for instance, one possible solution is to not use Angular HttpClient but an anchor with an href that points to your ever backend handler method directly.
If you need to use Angular HttpClient, perhaps to include your auth tokens, then you can try the approach proposed in this great SO question.
First, in your handler, encode to Base64 the zipped file contents to simplify the task of byte handling (in a general use case, you can typically return from your server a JSON object with the file content and metadata describing that content, like content-type, etcetera):
server.createContext("/files/downloadZip", new HttpHandler() {
#Override
public void handle(HttpExchange exchange) throws IOException {
if (!handleTokenPreflight(exchange)) { return; }
System.out.println(exchange.getRequestURI());
Map<String, String> queryParam = parseQueryParam(exchange.getRequestURI().getQuery());
String authToken = exchange.getRequestHeaders().getFirst("token");
String target = queryParam.get("target") + ",";
String[] files = new String[Integer.parseInt(queryParam.get("numberOfFiles"))];
[...] // I process the data in this entire method and send it to the previous method that creates a zip
// Get a reference to the zipped file
File selectedFilesZipFile = Controller.getDownloadZip(files, folderName);
// Set the appropiate Content-Type
exchange.getResponseHeaders().set("Content-Type", "application/zip");
// Download the file
byte[] fileContent = Files.readAllBytes(selectedFilesZipFile.toPath());
byte[] base64Data = Base64.getEncoder().encode(fileContent);
exchange.sendResponseHeaders(200, base64Data.length);
try (OutputStream responseBody = httpExchange.getResponseBody()) {
// Here I am using Commons-IO IOUtils: again, please, feel free to use other alternatives for writing
// the base64 data to the response outputstream
IOUtils.write(base64Data, responseBody);
responseBody.flush();
}
}
});
After that, use the following code in you client side Angular component to perform the download:
this.downloadService.httpGetDownloadZip(['target1','target2']).pipe(
tap((b64Data) => {
const blob = this.b64toBlob(b64Data, 'application/zip');
const blobUrl = URL.createObjectURL(blob);
window.open(blobUrl);
})
).subscribe()
As indicated in the aforementioned question, b64toBlob will look like this:
private b64toBlob(b64Data: string, contentType = '', sliceSize = 512) {
const byteCharacters = atob(b64Data);
const byteArrays = [];
for (let offset = 0; offset < byteCharacters.length; offset += sliceSize) {
const slice = byteCharacters.slice(offset, offset + sliceSize);
const byteNumbers = new Array(slice.length);
for (let i = 0; i < slice.length; i++) {
byteNumbers[i] = slice.charCodeAt(i);
}
const byteArray = new Uint8Array(byteNumbers);
byteArrays.push(byteArray);
}
const blob = new Blob(byteArrays, {type: contentType});
return blob;
}
Probably you will need to slightly modify the httpGetDownloadZip method in your service to take into account the returned base 64 data - basically, change ServerAnswer to string as the returned information type:
httpGetDownloadZip(target: string[]): Observable<string> {
const params = new HttpParams().set('target', String(target)).set('numberOfFiles', String(target.length));
const headers = new HttpHeaders().set('token', this.tokenService.getStorageToken());
const options = {
headers,
params,
};
return this.http
.get<string>(this.BASE_URL + '/files/downloadZip', options)
.pipe(catchError(this.handleError<ServerAnswer>('httpGetZip')));
}
You could try using responseType as arraybuffer.
Eg:
return this.http.get(URL_API_REST + 'download?filename=' + filename, {
responseType: 'arraybuffer'
});
In My Project including both front end (angular) and back end (java).
We used the below solution ( hope it work for you ):
Angular:
https://github.com/eligrey/FileSaver.js
let observable = this.downSvc.download(opts);
this.handleData(observable, (data) => {
let content = data;
const blob = new Blob([content], { type: 'application/pdf' });
saveAs(blob, file);
});
Java:
public void download(HttpServletRequest request,HttpServletResponse response){
....
response.setHeader("Content-Disposition",
"attachment;filename=\"" + fileName + "\"");
try (
OutputStream os = response.getOutputStream();
InputStream is = new FileInputStream(file);) {
byte[] buf = new byte[1024];
int len = 0;
while ((len = is.read(buf)) > -1) {
os.write(buf, 0, len);
}
os.flush();
}
You can still use HttpServletRequest on the server...
Then get its OutputStream and write to it.
#RequestMapping(method = RequestMethod.POST , params="action=downloadDocument")
public String downloadDocument(#RequestParam(value="documentId", required=true) String documentId,
HttpServletRequest request,
HttpServletResponse response )
{
try {
String docName = null;
String documentSavePath = getDocumentSavePath();
PDocument doc = mainService.getDocumentById(iDocumentId);
if(doc==null){
throw new RuntimeException("document with id: " + documentId + " not found!");
}
docName = doc.getName();
String path = documentSavePath + ContextUtils.fileSeperator() + docName;
response.setHeader("Content-Disposition", "inline;filename=\"" + docName + "\"");
OutputStream out = response.getOutputStream();
response.setContentType("application/word");
FileInputStream stream = new FileInputStream(path);
IOUtils.copy(stream, out);
out.flush();
out.close();
} catch(FileNotFoundException fnfe){
logger.error("Error downloading document! - document not found!!!! " + fnfe.getMessage() , fnfe);
} catch (IOException e) {
logger.error("Error downloading document!!! " + e.getMessage(),e);
}
return null;
}
As shown in the code below, we have an FtpInboundFileSynchronizingMessageSource with a FileSystemPersistentAcceptOnceFileListFilter using PropertiesPersistingMetadataStore.
#Bean
public PropertiesPersistingMetadataStore getMetadataStore() {
final PropertiesPersistingMetadataStore metadataStore = new PropertiesPersistingMetadataStore() {
#Override
public String putIfAbsent(final String key, final String value) {
try {
super.afterPropertiesSet();
} catch (final Exception e) {
e.printStackTrace();
}
return super.putIfAbsent(key, value);
}
};
metadataStore.setBaseDirectory(getRegistryValue("LOCALMETASTOREDIRECTORY"));
return metadataStore;
}
#Bean
#InboundChannelAdapter(value = "CSVChannel", poller = #Poller(fixedRate = "30000", maxMessagesPerPoll = "1"))
public MessageSource<File> ftpMessageSource() {
final String METHODNAME = "ftpMessageSource()";
if (LoggingHelper.isEntryExitTraceEnabled(LOGGER)) {
LOGGER.entering(CLASSNAME, METHODNAME);
}
final Comparator<File> fileLastModifiedDateComparator = new Comparator<File>() {
#Override
public int compare(final File f1, final File f2) {
return Long.valueOf(f1.lastModified())
.compareTo(f2.lastModified());
}
};
final FtpInboundFileSynchronizingMessageSource source = new FtpInboundFileSynchronizingMessageSource(ftpInboundFileSynchronizer(), fileLastModifiedDateComparator);
source.setLocalDirectory(new File(getRegistryValue("LOCALDIRECTORY")));
final FileSystemPersistentAcceptOnceFileListFilter fileSystemPersistentAcceptOnceFileListFilter = new FileSystemPersistentAcceptOnceFileListFilter(getMetadataStore(),
getRegistryValue("REMOTEFILENAMEPATTERN_ANAG_CLI"));
fileSystemPersistentAcceptOnceFileListFilter.setFlushOnUpdate(true);
source.setLocalFilter(fileSystemPersistentAcceptOnceFileListFilter);
if (LoggingHelper.isEntryExitTraceEnabled(LOGGER)) {
LOGGER.exiting(CLASSNAME, METHODNAME);
}
return source;
}
We have 4 instances of the application running in production and the local directory, meta store directory are all on a location shared by all 4 instances.
The problem we facing now is we are seeing invalid characters written in the metadata-store.properties file and sometimes there is some process writing this character \u0000 continuously and that causes the file to grow in big size, like 1GB in few minutes. And since the metadata is read in to memory by the framework that is causing outofmemoryexception when the file is very big.
Please see below some entries from the metadata-store.properties file below.
ANAG_CLI_*.CSV/opt/user-integration/anagcli/input/20200609113855907_ANAG_CLI_20200609113846.CSV.a=1591695480000
\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000=
ANAG_CLI_*.CSV/opt/user-integration/anagcli/input/20200610105125916_ANAG_CLI_20200610105118.CSV.a.writing=1591779085951
\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000=
\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000=
\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000=
\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000=
ANAG_CLI_*.CSV/opt/user-integration/anagcli/input/20200609133155929_ANAG_CLI_20200609133146.CSV.a=1591702315917
Is it safe to use the PropertiesPersistingMetadataStore like this in a shared location between more than one application instances? How to understand what is causing this invalid character issue and how to avoid this?
Any help would be appreciated!
I added a step in my application to persist files via GridFS and added a metadata field called "processed" to work as a flag for a scheduled task that retrieves the new file and sends it on for processing. Since the Java driver for GridFS doesn't have a method allowing metadata to be updated I used MongoCollection for the "fs.files" collection to update "metadata.processing" to true.
I use GridFSBucket.find(eq("metadata.processed", false) to get the new files for processing and then update metadata.processed to true once processing is completed. This works if I add a new file while the application is running. However, if I have an existing file with "metadata.processed" set to false and start the application, the above find call returns no results. Similarly if I have a file that was already processed and I set the "metadata.processed" field back to false, the above find call also ceases working.
private static final String FILTER_STR = "'{'\"filename\" : \"{0}\"'}'";
private static final String UPDATE_STR =
"'{'\"$set\": '{'\"metadata.processed\": \"{0}\"'}}'";
#Autowired
private GridFSBucketFactory gridFSBucketFactory;
#Autowired
private MongoCollectionFactory mongoCollectionFactory;
public void storeFile(String filename, DateTime publishTime,
InputStream inputStream) {
if (fileExists(filename)) {
LOGGER.info("File named {} already exists.", filename);
} else {
uploadToGridFS(filename, publishTime, inputStream);
LOGGER.info("Stored file named {}.", filename);
}
}
public GridFSDownloadStream getFile(BsonValue id) {
return gridFSBucketFactory.getGridFSBucket().openDownloadStream(id);
}
public GridFSDownloadStream getFile(String filename) {
final GridFSFile file = getGridFSFile(filename);
return file == null ? null : getFile(file.getId());
}
public GridFSFindIterable getUnprocessedFiles() {
return gridFSBucketFactory.getGridFSBucket()
.find(eq("metadata.processed", false));
}
public void setProcessed(String filename, boolean isProcessed) {
final BasicDBObject filter =
BasicDBObject.parse(format(FILTER_STR, filename));
final BasicDBObject update =
BasicDBObject.parse(format(UPDATE_STR, isProcessed));
if (updateOne(filter, update)) {
LOGGER.info("Set metadata for {} to {}", filename, isProcessed);
}
}
private void uploadToGridFS(String filename, DateTime publishTime,
InputStream inputStream) {
gridFSBucketFactory.getGridFSBucket().uploadFromStream(filename,
inputStream, createMetadata(publishTime));
}
private GridFSUploadOptions createMetadata(DateTime publishTime) {
final Document metadata = new Document();
metadata.put("processed", false);
// metadata.put("publishTime", publishTime.toString());
return new GridFSUploadOptions().metadata(metadata);
}
private boolean fileExists(String filename) {
return getGridFSFile(filename) != null;
}
private GridFSFile getGridFSFile(String filename) {
return gridFSBucketFactory.getGridFSBucket()
.find(eq("filename", filename)).first();
}
private boolean updateOne(BasicDBObject filter, BasicDBObject update) {
try {
mongoCollectionFactory.getFsFilesCollection().updateOne(filter,
update, new UpdateOptions().upsert(true));
} catch (final MongoException e) {
LOGGER.error(
"The following failed to update, filter:{0} update:{1}",
filter, update, e);
return false;
}
return true;
}
Any idea what I can do to ensure:
GridFSBucket.find(eq("metadata.processed", false)
returns the proper results for existing files and/or files that have had the metadata changed?
The issue was due to setting the metadata.processed value as a String vs a boolean.
When initially creating the metadata I set its value with a boolean:
private GridFSUploadOptions createMetadata(DateTime publishTime) {
final Document metadata = new Document();
metadata.put("processed", false);
// metadata.put("publishTime", publishTime.toString());
return new GridFSUploadOptions().metadata(metadata);
}
And later I check for a boolean:
public GridFSFindIterable getUnprocessedFiles() {
return gridFSBucketFactory.getGridFSBucket()
.find(eq("metadata.processed", false));
}
But when updating the metadata using the "fs.files" MongoCollection I incorrectly added quotes around the boolean value here:
private static final String UPDATE_STR =
"'{'\"$set\": '{'\"metadata.processed\": \"{0}\"'}}'";
Which caused the metadata value to be saved as a String vs a boolean.
Using Play Framework (version 2.3.x) (Java style), I am trying to serve an .mp3 file to the browser. Since it is a 'large' file I have decided to go with Play's ByteChunks Object, as follows.
#With(MP3Headers.class)
public static Result test() {
Chunks<byte[]> chunks = new ByteChunks() {
public void onReady(Chunks.Out<byte[]> out) {
try {
byte[] song = Files.readAllBytes(Paths.get("public/mp3/song.mp3"));
out.write(song);
} catch(Exception e) {
e.printStackTrace();
} finally {
out.close();
}
}
};
return ok(chunks);
}
For clarification, my Mp3Headers file, which is responsable for setting the headers so that the browser knows what type the payload has:
public class MP3Headers extends Action.Simple {
public Promise<Result> call(Http.Context ctx) throws Throwable {
ctx.response().setContentType("audio/mpeg");
return delegate.call(ctx);
}
}
For completion, my routes file:
# Routes
# This file defines all application routes (Higher priority routes first)
# ~~~~
# Home page
GET / controllers.Application.index()
GET /test controllers.Application.test()
# Map static resources from the /public folder to the /assets URL path
GET /assets/*file controllers.Assets.at(path="/public", file)
As is to be expected, navigating to localhost:9000/test renders to a nice HTML5 audio player (see picture).
The problem I have is that 'scrolling' in the audio player does not work. If I do scroll, the music pauses, and when I let go (when I 'chose' a position in time), it continues where it first paused.
I hope that I make sense, and I hope that you guys know something more about this. Thanks in advance.
You will need to tell your browser that your server support range requests and implement the ranges responses (ie just provide the part of the music the browser needs). You can get an overview of the request/response cycle in this answer.
#With(MP3Headers.class)
public static Result test() {
final int begin, end;
final boolean isRangeReq;
response().setHeader("Accept-Ranges", "bytes");
if (request().hasHeader("RANGE")) {
isRangeReq = true;
String[] range = request().getHeader("RANGE").split("=")[1].split("-");
begin = Integer.parseInt(range[0]);
if (range.length > 1) {
end = Integer.parseInt(range[1]);
} else {
end = song.length-1;
}
response().setHeader("Content-Range", String.format("bytes %d-%d/%d", begin, end, song.length));
} else {
isRangeReq = false;
begin = 0;
end = song.length - 1;
}
Chunks<byte[]> chunks = new ByteChunks() {
public void onReady(Chunks.Out<byte[]> out) {
if(isRangeReq) {
out.write(Arrays.copyOfRange(song, begin, end));
} else {
out.write(song);
}
out.close();
}
};
response().setHeader("Content-Length", (end - begin + 1) + "");
if (isRangeReq) {
return status(206, chunks);
} else {
return status(200, chunks);
}
}
Note that in this code the song was already loaded in song. Also the parsing of the RANGE header is very dirty (you can get values like RANGE:)
I Found this code very easy implementation.
Put the below action and its private helper method in your controller.
Controller Action
public static Result file(Long id, String filename) throws IOException {
Item item = Item.fetch(id);
File file = item.getFile();
if(file== null || !file.exists()) {
Logger.error("File no longer exist item"+id+" filename:"+filename);
return notFound();
}
String rangeheader = request().getHeader(RANGE);
if(rangeheader != null) {
String[] split = rangeheader.substring("bytes=".length()).split("-");
if(Logger.isDebugEnabled()) { Logger.debug("Range header is:"+rangeheader); }
if(split.length == 1) {
long start = Long.parseLong(split[0]);
long length = file.length()-1l;
return stream(start, length, file);
} else {
long start = Long.parseLong(split[0]);
long length = Long.parseLong(split[1]);
return stream(start, length, file);
}
}
// if no streaming is required we simply return the file as a 200 OK
if(Play.isProd()) {
response().setHeader("Cache-Control", "max-age=3600, must-revalidate");
}
return ok(file);
}
Stream Helper method
private static Result stream(long start, long length, File file) throws IOException {
FileInputStream fis = new FileInputStream(file);
fis.skip(start);
response().setContentType(MimeTypes.forExtension("mp4").get());
response().setHeader(CONTENT_LENGTH, ((length - start) +1l)+"");
response().setHeader(CONTENT_RANGE, String.format("bytes %d-%d/%d", start, length,file.length()));
response().setHeader(ACCEPT_RANGES, "bytes");
response().setHeader(CONNECTION, "keep-alive");
return status(PARTIAL_CONTENT, fis);
}
Complete example link is here Byte range requests in Play 2 Java Controllers