Main Tutorials

How to download file from website- Java / Jsp

Here i show a simple java example to demonstrate how to let user download a file from website. No matter you are using struts , JSP, Spring or whatever other java framework, the logic is same.

1) First we have to set HttpServletResponse response to tell browser about system going to return an application file instead of normal html page


response.setContentType("application/octet-stream");
response.setHeader("Content-Disposition",
"attachment;filename=downloadfilename.csv");

we can also specified a download file name in attachment;filename=, above example export a csv file name “downloadfilename.csv” for user download.

2) There have 2 ways to let user download a file from website

Read file from physical location


File file = new File("C:\\temp\\downloadfilename.csv");
FileInputStream fileIn = new FileInputStream(file);
ServletOutputStream out = response.getOutputStream();

byte[] outputByte = new byte[4096];
//copy binary contect to output stream
while(fileIn.read(outputByte, 0, 4096) != -1)
{
	out.write(outputByte, 0, 4096);
}
fileIn.close();
out.flush();
out.close();

Export database data or string directly to InputStream for user download.


StringBuffer sb = new StringBuffer("whatever string you like");
InputStream in = new ByteArrayInputStream(sb.toString().getBytes("UTF-8"));
ServletOutputStream out = response.getOutputStream();

byte[] outputByte = new byte[4096];
//copy binary contect to output stream
while(in.read(outputByte, 0, 4096) != -1)
{
	out.write(outputByte, 0, 4096);
}
in.close();
out.flush();
out.close();

3) Done

Here i show my struts example to demonstrate how to directly write data into InputStream and output it as “temp.cvs” to let user download.


public ActionForward export(ActionMapping mapping, ActionForm form,
	HttpServletRequest request, HttpServletResponse response)
	throws Exception {
				
	//tell browser program going to return an application file 
        //instead of html page
        response.setContentType("application/octet-stream");
        response.setHeader("Content-Disposition","attachment;filename=temp.csv");
				
	try 
	{
		ServletOutputStream out = response.getOutputStream();
		StringBuffer sb = generateCsvFileBuffer();
					
		InputStream in = 
                    new ByteArrayInputStream(sb.toString().getBytes("UTF-8"));
					
		byte[] outputByte = new byte[4096];
		//copy binary contect to output stream
		while(in.read(outputByte, 0, 4096) != -1)
		{
			out.write(outputByte, 0, 4096);
		}
		in.close();
		out.flush();
		out.close();
					
	  }
	  return null;
	}

private static StringBuffer generateCsvFileBuffer()
{
	StringBuffer writer = new StringBuffer();

	writer.append("DisplayName");
	writer.append(',');
	writer.append("Age");
	writer.append(',');
	writer.append("HandPhone");
	writer.append('\n');

        writer.append("mkyong");
	writer.append(',');
	writer.append("26");
	writer.append(',');
	writer.append("0123456789");
	writer.append('\n');
			
	return writer;
}

Here’s a file download example in Servlet code

About Author

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Founder of Mkyong.com, love Java and open source stuff. Follow him on Twitter. If you like my tutorials, consider make a donation to these charities.

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assman
14 years ago

There is no need to split the string into bytes and then write it to the output stream. You should explain the reason you do this because it doesn’t make sense and its error prone.

Instead of :

InputStream in = new ByteArrayInputStream(sb.toString().getBytes(“UTF-8”));

byte[] outputByte = new byte[4096];
//copy binary contect to output stream
while(in.read(outputByte, 0, 4096) != -1)
{
out.write(outputByte, 0, 4096);
}

Just do the following:

out.print(sb);

Much much better.

Anamika
10 years ago
Reply to  assman

l like this blog as it too useful and nice way to solve problems…

yogesh
14 years ago
Reply to  assman

nothing to reply

shreekanth
2 years ago

HI team,
I want to download more than 12 gb file using inputstream in java(Spring boot)

Please help me

Gousepeer
3 years ago

am Using the same code for my requirement, after downloading the csv file first line am getting a blank row, which the blank row is not there in the server csv file.Please help…

PrathapReddy
4 years ago

Hi,

I am having issue while downloading the large set of data. it showing “Your browser sent a request that this server could not understand.” i am using below code …

byte[] bytes = getBytes();

response.setContentType(“application/vnd.ms-excel”);

response.setHeader(“Content-disposition”, “attachment;filename=export.xlsx”);

OutputStream out = response.getOutputStream();

out.write(bytes);

out.flush();

out.close();

Nitin
9 years ago

Hi,

I am having issue while downloading the large set of data. it showing “Your browser sent a request that this server could not understand.” i am using below code …

byte[] bytes = getBytes();

response.setContentType(“application/vnd.ms-excel”);

response.setHeader(“Content-disposition”, “attachment;filename=export.xlsx”);

OutputStream out = response.getOutputStream();

out.write(bytes);

out.flush();

out.close();

SudhaVelan
9 years ago

Hi I m trying to save the return string as zip file.But the file is stored as encoded.
Response header :

Content-Disposition: attachment; filename=”filename.extension”
Keep-Alive: timeout=5, max=100
Connection: Keep-Alive
Transfer-Encoding: chunked
Content-Type: application/octet-stream

I tried to read as follow :
InputStream input = response.getEntityInputStream();
byte[] buffer = new byte[4096];
int n = – 1;

OutputStream output = new FileOutputStream( file );
while ( (n = input.read(buffer)) != -1)
{
if (n > 0)
{
output.write(buffer, 0, n);
}
}

But the file is saved as encoded.

Can you please suggest any thing else?
Its a zip file

Chris
8 years ago
Reply to  SudhaVelan

Did you find a fix for this?

rohit
9 years ago

i am getting junk data along with csv while downloading from screen.the junk data is source page of jsp

Rajeswar
8 years ago
Reply to  rohit

Hi same here. Did you manage to solve it?

Chris
8 years ago
Reply to  Rajeswar

I am getting the right response, but I cannot tell where the file is being downloaded to. I don’t get any kind of save dialog from the browser. Where is the download supposed to go?

naresh
9 years ago
Reply to  rohit

how you get it solved

KyungHwan Min
10 years ago

I just want to leave one comment. If you download xlsx Excel file, writing codes in JSP will result in file corruption. Writing download logic in servlet is working from my experiment.

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

response.setContentType(“text/html”);
String filename = request.getParameter(“filename”);
//System.out.println(“Filename = ” + filename);
response.setContentType(“application/octet-stream”);
response.setHeader(“Content-Disposition”,”attachment;filename=”+filename);
String basePath = “/root/sub_path”;
File file= new File(basePath+”/”+filename);
System.out.println(“Filename = ” + basePath+”/”+filename);
FileInputStream fileIn = new FileInputStream(file);
ServletOutputStream sos = response.getOutputStream();

byte[] outputByte = new byte[4096];

while(fileIn.read(outputByte, 0, 4096) != -1 )
{
sos.write(outputByte , 0, 4096);
}
fileIn.close();
sos.flush();
sos.close();
}

Ahmed
10 years ago

Hallo,

Can you explain how can i download files with Apache Wicket?

Thanx!

Soheb
10 years ago
Soheb
10 years ago

I am using JSF and in one of the managed bean (view scope) i have a method as:

public String viewReport() {

HttpServletResponse response = (HttpServletResponse) FacesContext.getCurrentInstance().getExternalContext().getResponse();

response.setContentType(“application/vnd.ms-excel”);
response.setHeader(“Content-Disposition”,”attachment;filename=book1.xls”);

try {
File file = new File(“C:\\soheb\\book1.xls”);
FileInputStream fileIn = new FileInputStream(file);
ServletOutputStream out = response.getOutputStream();

byte[] outputByte = new byte[4096];
//copy binary contect to output stream
while(fileIn.read(outputByte, 0, 4096) != -1)
{
out.write(outputByte, 0, 4096);
}
fileIn.close();
out.flush();
out.close();
}
catch(IOException e) {
e.printStackTrace();
}
return null;
}

The excel which is getting retrieved is corrupted file. It has some strange characters above and below is the entire code of JSP. I even tried application/octet-stream for contenttype too.

I tried the same with a plain text file and i was able to open it through.

Please help me with this problem, Thanks in advance.

_
11 years ago

Whats up are using WordPress for your site platform? I’m new to the blog world but I’m trying to get started and create my own.
Do you need any html coding expertise to make your own blog?
Any help would be really appreciated!

Jia Bin
12 years ago

Hi, is this possible to do this in struts 2? Thanks…

Enrico Bergamo
12 years ago

Hello, I’m having the same problem as Nayana here. My files are stored in a BLOB field in DB2. I’m trying to retrieve them, but I only have success for text files, but we need to retrieve DOC, PDF and XLS as well.

Considering they are stored base64 encoded, I’m using the following code to download the file, but as I said before, just worked on text files



<%@ page import="java.io.*"%>
<%@ page import="com.ibm.misc.*"%>

<%
	String fileName = request.getParameter("fileName");
	String fileType = request.getParameter("fileType");
	String fileContent = b64Decode(request.getParameter("fileContent"));//Blob content

	response.setContentType(fileType);
	//response.setContentType("application/octet-stream");
	response.setHeader("Content-Disposition", "attachment;filename=\""
			+ fileName + "\"");
	response.setContentLength((int) fileContent.length());

	try {

		StringBuffer sb = new StringBuffer(fileContent);
		InputStream in = new ByteArrayInputStream(sb.toString().getBytes());
		//InputStream in = new ByteArrayInputStream(sb.toString().getBytes("UTF-8"));
		ServletOutputStream sos = response.getOutputStream();

		byte[] outputByte = new byte[4096];
		//copy binary contect to output stream
		while (in.read(outputByte, 0, 4096) != -1) {
			sos.write(outputByte, 0, 4096);
		}
		in.close();
		sos.flush();
		sos.close();

	} catch (IOException ex) {
		ex.printStackTrace();
	}
%>

<%!public String b64Decode(String msg) {
		BASE64Decoder decoder = new BASE64Decoder();
		byte[] decodedBytes = null;
		try {
			decodedBytes = decoder.decodeBuffer(msg);
		} catch (IOException e) {
			e.printStackTrace();
		}
		return new String(decodedBytes);
	}%>

Rodney
11 years ago
Reply to  Enrico Bergamo

Oh This Works All Fine, But I Want To Download A Password Protected File From The Net Like In Firefox When The URL is Entered It Prompts A Password Box To Download The File.

With This Code So Far I Get Errors As The Web Host Gives Access Denied.

¿ I Want [Yeah I Demand] A Code in That if The File [URL] is Password Protected It Will Tell You To Enter The Password And Then Download The File if Password is Correct?

Thank-You BTW

sara
12 years ago
Reply to  Enrico Bergamo

hello sir,
i want clear code for downloading files in jsp

Nayana
12 years ago

I have stored excel file as BLOB. On click of filename in the JSP user should be able to retrieve the BLOB and display it in the excel. Could you please help me here?

Anamika
10 years ago
Reply to  Nayana

I am also looking to learn java can you share any website where I can learn it properly.

Gabe T.
12 years ago

Thank you so very very much for sharing your solution online :D!
Exactly what I was looking for.
Much appreciated, sir :)!

Nikhil
12 years ago

Hi,

I am using

response.setContentType(“application/octet-stream”);
response.setHeader(“Content-Disposition”, “attachment;filename=” + outfile.getName());

It ends up downloading my jsp page in test format.

Please help.

Thanks & Regards,
Nikhil

webcom
12 years ago
Reply to  Nikhil

response.setContentType(“application/octet-stream”);
response.setHeader(“Content-Disposition”, “attachment;filename=” + outfile.getName());

The great thing i discovered is you actually dont need to specify the application type in order to open downloaded file. Since outfile.getName() parameter contains the file extension (myfile.txt, myfile.doc…), any file type can be downloaded with this Content type declaration
I tried this with Word, PDF, XLS, JPG, MPG, ZIP they all work with “application/octet-strea” with no problem

Sunaina
10 years ago
Reply to  webcom

I want to learn java please tell me any website where I can learn it.

Tomino
12 years ago

Hi,

I did it this way. It works great in Mozilla and IE7 and bellow. But same code doesn’t work in IE8. When executing out.flush() or out.close(), the browser gets closed with no exception thrown. Does anybody have an idea what is wrong?

I tried content type “application/octet-stream”, “application/force-download” as well as “application/vnd.ms-excel”, cause I download an excel file.

Shashank
12 years ago

Hi,

I modified the above code to download a word document. Below are the changes –

response.setContentType(“application/doc”);
response.setHeader(“Content-disposition”,”attachment; filename=Wordfile.doc”);

The document downloads fine. But when I open the document in MSWord, I get the below error –

“Word Cannot Start the Converter MSWRD632.WPC”

After clicking the OK button a couple of times the documents opens up fine. Please let me how to fix this issue.

Roshan
13 years ago

Thanks very much… you save my time…you have release my stress..Thanks again..god bless u..

Pochacco
13 years ago

Hi, I’m a little confused as to where I put these codes into.
Sorry I’m not so good with html stuff.

Sibyl Cocoran
13 years ago

hi-ya, great post.

mahesh
13 years ago

very useful content dude

Haja
13 years ago

while(in.read(outputByte, 0, 4096) != -1)
{
out.write(outputByte, 0, 4096);
}

change this code to

int byteRead;
while((byteRead = in.read(outputByte, 0, 4096)) != -1)
{
out.write(outputByte, 0, byteRead );
}

Gachugu
12 years ago
Reply to  Haja

Excellent! And this addition was very nice too… otherwise the download appends bytes to make the chunk 4096! Good work guys.

Onymakris
12 years ago
Reply to  Haja

Great article. Thanks.

Von Landon
10 years ago
Reply to  mkyong

Please update the code at the top of this page to reflect this important fix.

Ronnie
14 years ago

From my web layer i pass an id value, then a type value(string), and two ate values….
Actually i useed an Http service and sent these parameters using send() method to the EJB…

Ronnie
14 years ago
Reply to  mkyong

Thx Yong 🙂

Marlie
12 years ago
Reply to  mkyong

Superior thinking denmsortated above. Thanks!

Ronnie
14 years ago
Reply to  mkyong

Thx Yong 🙂
But cud u plz tel me hw to pass the response object from web layer? Can you explain it briefly using an example??

Ronnie
14 years ago

When i use response.setContentType statement ,
it says response has not been initialized….

Ronnie
14 years ago

I have changed the writer to StringBuffer Type..
So tat is not the issue 🙂

Ronnie
14 years ago

Hi,
Sorry for the delay.
Plz find my code below. It is givin an exception. This code is in a Session Bean. The input is coming from Flex. Iam able to generate the file, but not able to make it available as a downloadable file 🙁

Could you plz help me out…
Its kinda urgent…..

Thx in Advance…
Also i would appreciate if this code isnt made public….

Also iam new to httprequest and response part…
Plz enligten me on wat i shud be sending in the request, from wer i shud be sending the request and wat response shud hold….

Code:

public void exportPowerData(int id,String type,String from,String to)
{

………………….

String sFileName = “c:\\test.csv”;

response.setContentType(“application/octet-stream”);
response.setHeader(“Content-Disposition”,”attachment;filename=sFileName”);

Date fromTimeStamp = stringToDate(from);
Date toTimeStamp = stringToDate(to);

System.out
.println(“INFO:************* Executing EJB ********************** “);

Session session = HibernateUtil.getSessionFactory().openSession();

Criteria crit =
session.createCriteria(Power.class);

crit.add(Restrictions.between(“lastUpdatedOn”, new Date(fromTimeStamp.getTime()), new Date(toTimeStamp.getTime())));

List list = crit.list();

FileWriter writer = new FileWriter(sFileName);

writer.append(“Dc_Equipment”);
writer.append(‘,’);
writer.append(“Equipment Type”);
writer.append(‘,’);
writer.append(“Last_UpdatedOn”);
writer.append(‘,’);
writer.append(“Power(In Watts)”);
writer.append(‘\n’);

for(Iterator it = list.iterator();it.hasNext();)
{
Power p = (Power)it.next();

System.out.println(“Home: ” + p.getHome());
System.out.println(“Type: ” + p.getType());
System.out.println(“Last_Updated_On: ” + p.getLastUpdatedOn());
System.out.println(“Power: ” + p.getValue());

String str = p.getHome();
String str1 = p.getType();
String str2 = p.getLastUpdatedOn();
String str3 = p.getValue();
double d = Double.valueOf(str3).doubleValue();

total_power = d+total_power;
String dbl_to_str = Double.toString(d);

writer.append(str);
writer.append(‘,’);
writer.append(str1);
writer.append(‘,’);
writer.append(str2);
writer.append(‘,’);
writer.append(dbl_to_str);
writer.append(‘\n’);

}

System.out.println(“Total Power Consumed:” +total_power);
String dbl_to_str1 = Double.toString(total_power);
writer.append(“Total Power: “);
writer.append(dbl_to_str1);
writer.append(“\n”);

FileInputStream fileIn = new FileInputStream(sFileName);
ServletOutputStream out = response.getOutputStream();

byte[] outputByte = new byte[4096];
//copy binary content to output stream
while(fileIn.read(outputByte, 0, 4096) != -1)
{
out.write(outputByte, 0, 4096);
}
fileIn.close();
out.flush();
out.close();

//fileDownload(writer);

writer.flush();
writer.close();

session.clear();
transaction.commit();
session.close();
HibernateUtil.shutDown();

//return null;

}catch(Exception e){
System.out.println(e.getMessage());

}

}

public Date stringToDate(String value)
{
try
{
DateFormat formatter ;
Date date ;
formatter = new SimpleDateFormat(“yyyy-MM-dd”);
date = (Date)formatter.parse(value);
return date;

} catch (ParseException e)
{System.out.println(“Exception :”+e);
return null;
}

}

public static void main(String args[])
{

ExportDataEJB obj = new ExportDataEJB();

obj.exportPowerData(1, “Home”, “2009-10-30”, “2009-11-06”);

}