I need a download a text/plain file in to a folder. The url does not end with .txt but it has content-type etc... properly set. When I use the browser it immediately prompts me to save the file. The browser automatically puts proper file name also.
Using java how can i download that url in to a folder? Note that I dont know the filename also but I want the file to be saved in a directory.
code to download a file is easy... my question is that I dont know by what name should i save my file. the filename is part of content-disposition header, now how do i extract that?
The HTTP protocol uses the HTTP headers to define some information about the data transferred.
You have the content-disposition header that can have a property filename that is generated by the server. This holds the name of the file being transferred. But it is optional. Should you handle the case it is not present. Here is the doc: http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html
Depending on how you download the file, you'll have dozen of ways to retrieve this file name from the http header.
Give a look to the apache http client for instance.
HIH
M.
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I am trying to figure out how to get the default file name of a file I download using an HttpUrlConnection.
I use a REST API to download the file so I can't parse the URL for the name and the "Content-Disposition" header doesn't contain the name either but when I put the link in my browser it will download the file with the right name so I'm thinking it must be possible to get the name from the result of the HTTP request somehow.
I have read the following two posts which addressed this problem without solving it for my particular situation: HttpURLConnection downloaded file name and
Get download file name from URL or HttpUrlConnection?
For my web site, I need to get some data from an URL whose response headers contains Content-Disposition attribute which forces me to download the file. I would like to know how I can read the content of the file without downloading the file to disk and do I/O to read it.
Doing so in either Java or JavaScript would be fine.
Content-Disposition is just advisory. If you use a non-browser client (Java, curl, wget...) and do a GET request, you can just do whatever you want.
(I guess this means your question isn't sufficiently specific)
In downloading a file (Eclipse's win32 zip) from the following URL in Firefox, the filename is known to be eclipse-jee-juno-SR1-win32.zip.
http://www.eclipse.org/downloads/download.php?file=/technology/epp/downloads/release/juno/SR1/eclipse-jee-juno-SR1-win32.zip&url=http://download.eclipse.org/technology/epp/downloads/release/juno/SR1/eclipse-jee-juno-SR1-win32.zip&mirror_id=1
However, this file name is not specified in the Content-disposition header, which is the standard method of acquiring the server-suggested file name.
Here, eclipse's download is simply an example. I see that the file name is a part of the URL, but is there an alternative method to get the file name? I could use regex to extract the file name from the URL in this case, but it isn't guaranteed to be a part of every URL without a Content-disposition header.
Question: How can the download's file name be acquired when no Content-disposition header is present? Or, more localized, how does Firefox come up with the aforementioned name?
Or is Firefox simply parsing the URL here, and I've come across a case where it simply happens to work despite extracting the file name from an indirect, script-delivered download?
Content Disposition is the standard method for the server to suggest a file name. In the absence of a content disposition header, it's entirely up to the client to come up with a file name. The most common option is to take the last segment of the path.
In the absence of a content disposition header, the server isn't even really saying that the url should be downloaded to a file rather than displayed. It's just that most browsers default to saving as a file anything they cannot display.
I am currently trying to use JSP to build some small litle apps and have not got stuck on something, downloading files from a webserver. I just cant seem to work out how I should go about this task.
Are there any JSP developers here who know to go about this and could point me in the right direction?
If the resource is static, just put it in the public webcontent (there where your JSP/HTML/CSS/JS/etc files also are) and include a link to it in your JSP.
download
The servletcontainer will worry about setting the right HTTP response headers.
If the resource is dynamic, create a servlet which obtains an InputStream of the content somehow (new FileInputStream, resultSet.getBinaryStream(), etc..etc..) and writes it to the OutputStream of the response along at least the Content-Type and Content-Disposition response headers. Finally just link to that servlet in your JSP.
download
You can find a basic example in this article.
The Content-Type header informs the client about the content type of the file so that it knows what application it should use to open it. The Content-Disposition header informs the client what to do with it, displaying it inline or saving as attachment.
I'm creating a java web application runing on a Tomcat server.
One of the functions fill in a StringBuffer variable with data.
At the end, I would like to propose the user to download the generated content packaged in a text file. This without having to store the file on the server.
I've been searching for a code snippet but couldn't find anything corresponding ...
I hope I've been clear enough on my problem.
Thanks in advance,
See Making A Download Servlet
Don't forget to add the servlet to your web.xml.
You have to send a content-type along with the response, so that the browser knows what to do with the body of the response.
Normal text has the content-type text/plain, html is text/html. Images are image/gif and so on. For an unknown mime type you normally set "application/octet", which afaik every browser treats as a download. But I recommend to use the propery content type, so the browser might start a matching application to handle the content (e.g. Office for Documents or XML Editor for XML Files ..)
To send a filename along, which the browser suggests for saving, use the following header (example):
Content-Disposition: attachment; filename="downloaded.pdf"
For sending custom headers, use the setHeader() method in the response object.