Create Download Link But Source is Java String - java

I want to create a download link but the part I'm having trouble is that the source is a Java string. The String I have is a JSON data. I want people to be able to download that data.
I am using the Play! framework so I can pass the String data using the Scala template. But I'm not sure how to allow users to download the String and append the file types (.txt, .json) so that users actually download a file.
How do I go about to doing this?

I can't believe how simple the solution is. This was what did it for me. Basically take the string and convert it into an InputStream.
String data = "someBigOrSmallData";
InputStream dataStream = new ByteArrayInputStream(data.getBytes());
response().setHeader("Content-disposition","attachment; filename=anyFileName.txt");
return ok(dataStream);

Related

How do I upload a pdf to elasticsearch when using the elastic search java client?

This link explains how to use the REST API to upload an attachment.
But I want to upload an attachment with the java client...
I assume the following classes are relevant (though I may be wrong)...
org.elasticsearch.ingest.IngestService
org.elasticsearch.ingest.PipelineStore
I realize that I can just fall back to the REST interface but I'd rather try and use the native client first...
Just send a BASE64 encoded PDF in a field like:
String base64;
try (InputStream is = YourClass.class.getResourceAsStream(pathToYourFile)) {
byte bytes[] = IOUtils.toByteArray(is);
base64 = Base64.getEncoder().encodeToString(bytes);
}
IndexRequest indexRequest = new IndexRequest("index", "type", "id")
.setPipeline("foo")
.source(
jsonBuilder().startObject()
.field("field", base64)
.endObject()
);
In case you are not aware of it, I'm also linking to FSCrawler project in case it solves something you want to do already.
Here is four options that you can use to index PDFs to ElasticSearch
Ingest Attachment Plugin
Apache Tika
FsCrawler
Ambar
Pros/cons described in this post

How to update the content of a file in Google Drive?

I am trying to update the content of a Google Doc file with the content of another Google Doc file. The reason I don't use the copy method of the API is because that creates another file with another ID. My goal is to keep the current ID of the file. This is a code snippet which unfortunately does nothing:
com.google.api.services.drive.Drive.Files.Get getDraft = service.files().get(draftID);
File draft = driveManager.getFileBackoffExponential(getDraft);
com.google.api.services.drive.Drive.Files.Update updatePublished = service.files().update(publishedID, draft);
driveManager.updateFileBackoffExponential(updatePublished);
The two backoffExponential functions just launch the execute method on the object.
Googling around I found out that the update method offers another constructor:
public Update update(java.lang.String fileId, com.google.api.services.drive.model.File content, com.google.api.client.http.AbstractInputStreamContent mediaContent)
Thing is, I have no idea how to retrieve the mediaContent of a Google file such as a Google Doc.
The last resort could be a Google Apps Script but I'd rather avoid that since it's awfully slow and unreliable.
Thank you.
EDIT: I am using Drive API v3.
Try the Google Drive REST update.
Updates a file's metadata and/or content with patch semantics.
This method supports an /upload URI and accepts uploaded media with
the following characteristics:
Maximum file size: 5120GB Accepted Media MIME types: /*
To download a Google File in the format that's usable, you need to specify the mime-type. Since you're using Spreadsheets, you can try application/vnd.openxmlformats-officedocument.spreadsheetml.sheet. Link to Download files for more info.

How to retrieve file from database for use by front-end code? (rest using java and jersey)

I'm working on a chat application, and I need to process a get request for a file that has been uploaded to the database. I'm not sure if I should return an output stream or a file or what.
The idea is that it will be something like any other chat application where the image appears as message are loaded. Using an output stream seemed like the best option, but I wasn't sure how to create the output stream from the information in the database, which includes an id, checksum, name, size, and mime type.
So my questions are:
How should I approach this?
if output stream is the best way, what's the ideal way to implement it?
Any guidance is appreciated, please let me know if I can make the question more clear, or if more details are necessary to answer the question.
What I couldn't understand how to do is this: serve the image to the front-end/client code. As it turns out, it was super easy.
#GET #javax.ws.rs.Path("/file/{fileId}")
public Response getFile(#Context SecurityContext sc, #PathParam("id") long topicId, #PathParam("fileId") long fileId) {
TopicFile tFile = topicAccessor.getFile(fileId);
String fileLocation = "/server/uploads/" + tFile.getChecksum();
File file = new File(fileLocation);
return Response.ok(file, tFile.getType()).build();
}
Here TopicFile holds metadata for the file in the database, and the files are named their checksum.
So basically the solution to my problem was to return a Response. I hadn't thought of this earlier because I "inherited" this code, and I trusted that the previous person had god reason not to use the Response class.

GridFS retrieve only a range of a file using java driver

The docs mention that it is possible to retrieve a range of a document using gridFS. However I haven't found any more details about this. I would like to obtain a range of a file using the java driver for a grails app to support audio streaming. Do I need to get and assemble the packages manually in that case or is there any better way?
You can skip over the part of the file not needed and read only what you need from there.
GridFSDBFile file = files.findOne("file");
InputStream inputStream = file.getInputStream();
long actuallySkipped = inputStream.skip(numberOfBytesToSkip);
// read from here...
Hope this helps.

Java Read binary record into String

We are storing uploaded text files in a SQL server data. The field type is image.
The file upload and download correctly, what I want to do now is load the actual text content into a String variable directly from the database record.
Can anyone advise on how to do this please?
Depends on how you read the data from the db. If you get a byte array, you could use new String(bytes);
Btw, why don't you use the CLOB datatype (or the equivalent for your server) for the field? This should normally cause the Java driver to return the String directly.

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