Uploading Single File by Using JSP
This
tutorial will help you to understand how you can upload a file by using the Jsp.
As Jsp is mainly used for the presentation logic, we should avoid to write a
code in the jsp page, but at least we should know how we can use a java code
inside the jsp page. In Jsp the logic of the program or Java code is mainly written inside the scriptlet.
In this example we are going to tell you how can make use of scriptlet to
upload a file.
In
this example we are going to tell you how we can upload a single file by using
Jsp and how it will get stored on a particular memory area. To get the desired
result firstly we need to need to make a jsp page which will work as a
controller, and to fulfill our requirements we need to import some packages, classes and interfaces.
For this program we are using one package java.io.* which provides us classes
and interfaces for java input/output.
The
logic of the program will be written inside the scriptlet. The scriptlet tag is
mostly used for writing the java code inside the jsp.
In the
scriptlet we have
used the method getContentType( ) of the implicit object request. This method is
used to get the content type information from the Jsp header. The next step we
are going to do is to check
the condition whether the content type is not equal to Null and as well as
the passed data from mulitpart/form-data is greater than or equal to 0. If the
condition is true make a object of DataInputStream. Inside the constructor of
the DataInputStream pass the getInputStream() method of the implicit object
request reference of the class InputStream. It will create a DataInputStream
that uses the specified underlying InputStream. A data input stream read
primitive Java data types from an underlying input stream.
Now we need to get the length of the
content type which will be passed as a parameter to the constructor of the byte
array. Now declare two int variables and initialize their values as 0. To
convert the uploaded file into the byte code use the while loop.
Now pass the array of dataBytes in the constructor of String class
and store it in the variable file. To save the file name we need to substring
the file object. After making the substring of the string we need to
extract the index of file. Upto now we have got the file name and the
index of file, now what we need is create an new file with the same name and
writing the content in new file. For this we will make a object of class File
and pass a new directory name which we want to make as a parameter in the
constructor of the File class. By using the File object method mkdir()
we will make a directory. To write the content in new file make a object of
class FileOutputStream.
We need another jsp page which will
be used for the presentation. This jsp page contains the information where the
request will be sent whenever it will get a request for file uploading. To
upload the file to the jsp page firstly we need to browse the files and get the
appropriate file. This will be achieved by the input type "file".
To save the file to the particular location we need a submit
button.
In this program firstly you will get
a jsp page which will have the option of browse and Send File. The logic behind
it will be controlled by the controller.
Here is the code of the index_single_upload.jsp:
<%@ page language="java" %>
<HTml>
<HEAD><TITLE>Display file upload form to the user</TITLE></HEAD>
<% // for uploading the file we used Encrypt type of multipart/
form-data and input of file type to browse and submit the file %>
<BODY> <FORM ENCTYPE="multipart/form-data" ACTION=
"sinle_upload_page.jsp" METHOD=POST>
<br><br><br>
<center><table border="2" >
<tr><center><td colspan="2"><p align=
"center"><B>PROGRAM FOR UPLOADING THE FILE</B><center></td></tr>
<tr><td><b>Choose the file To Upload:</b>
</td>
<td><INPUT NAME="F1" TYPE="file"></td></tr>
<tr><td colspan="2">
<p align="right"><INPUT TYPE="submit" VALUE="Send File" ></p></td></tr>
<table>
</center>
</FORM>
</BODY>
</HTML>
|
Output for the index_single_upload.jsp
Output After Clicking Browse Button:
Here is the code of the single_upload_page.jsp:
<%@ page import="java.io.*" %>
<%
//to get the content type information from JSP Request Header
String contentType = request.getContentType();
//here we are checking the content type is not equal to Null and
as well as the passed data from mulitpart/form-data is greater than or
equal to 0
if ((contentType != null) && (contentType.indexOf("multipart/
form-data") >= 0)) {
DataInputStream in = new DataInputStream(request.
getInputStream());
//we are taking the length of Content type data
int formDataLength = request.getContentLength();
byte dataBytes[] = new byte[formDataLength];
int byteRead = 0;
int totalBytesRead = 0;
//this loop converting the uploaded file into byte code
while (totalBytesRead < formDataLength) {
byteRead = in.read(dataBytes, totalBytesRead,
formDataLength);
totalBytesRead += byteRead;
}
String file = new String(dataBytes);
//for saving the file name
String saveFile = file.substring(file.indexOf("filename=\
"") + 10);
saveFile = saveFile.substring(0, saveFile.indexOf("\n"));
saveFile = saveFile.substring(saveFile.lastIndexOf("\\")
+ 1,saveFile.indexOf("\""));
int lastIndex = contentType.lastIndexOf("=");
String boundary = contentType.substring(lastIndex + 1,
contentType.length());
int pos;
//extracting the index of file
pos = file.indexOf("filename=\"");
pos = file.indexOf("\n", pos) + 1;
pos = file.indexOf("\n", pos) + 1;
pos = file.indexOf("\n", pos) + 1;
int boundaryLocation = file.indexOf(boundary, pos) - 4;
int startPos = ((file.substring(0, pos)).getBytes()).length;
int endPos = ((file.substring(0, boundaryLocation))
.getBytes()).length;
// creating a new file with the same name and writing the
content in new file
FileOutputStream fileOut = new FileOutputStream(saveFile);
fileOut.write(dataBytes, startPos, (endPos - startPos));
fileOut.flush();
fileOut.close();
%><Br><table border="2"><tr><td><b>You have successfully
upload the file by the name of:</b>
<% out.println(saveFile); %></td></tr></table> <%
}
%>
|
Output for Sinle_upload_page.jsp
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Current Comments
11 comments so far (post your own) View All Comments Latest 10 Comments:Can anyone tell what is happening in the following lines
String saveFile = file.substring(file.indexOf("filename=\"") + 10);
saveFile = saveFile.substring(0, saveFile.indexOf("\n"));
saveFile = saveFile.substring(saveFile.lastIndexOf("\\") + 1,saveFile.indexOf("\""));
int lastIndex = contentType.lastIndexOf("=");
String boundary = contentType.substring(lastIndex + 1,contentType.length());
Posted by Manoj on Wednesday, 08.13.08 @ 19:04pm | #72671
When user click browse button for file upload on one text box . i want to code how it possible .
Posted by Rakesh Biswal on Wednesday, 06.18.08 @ 12:29pm | #63702
hi
by default the file will get save in Domain directory,
if u wana save it to D drive then write.
FileOutputStream fileOut = new FileOutputStream("D:\\"+saveFile);
Posted by santosh gupta on Thursday, 06.12.08 @ 16:52pm | #63113
I download this program.It will work nice but it will stored in default path means images and any file whatever we upload it will be stored in default path.So if i want to change the path then what changes i have done in this program
Posted by Nisarg Shah on Thursday, 05.15.08 @ 11:36am | #60003
the file upload code is workin perfectly fine.
i want to change the location where it is stored. can anyone plz help me wit it?
thank u.
Posted by rohit on Tuesday, 05.13.08 @ 16:01pm | #59714
I had pasted the above provided 2 files(1.index_single_upload.jsp, 2.Sinle_upload_page.jsp) for file uploading it is showing errors in the netbeans IDE like
C:\Documents and Settings\Sasi\Attachemnt\build\generated\src\org\apache\jsp\index_005fsingle_005fupload_jsp.java:46: not a statement
form-data and input of file type to browse and submit the file
^
C:\Documents and Settings\Sasi\Attachemnt\build\generated\src\org\apache\jsp\index_005fsingle_005fupload_jsp.java:46: ';' expected
form-data and input of file type to browse and submit the file
^
can u please intimate we why it is so happening, i want the code very urgently, kindly respond to it asap.
sasi
Posted by sasi on Saturday, 03.22.08 @ 13:19pm | #53751
It works nice. The file is stored in the default path of installation( i.e path of installation Websphere application developer in my case)
How to change the path of the storing.?
Posted by Senthil on Tuesday, 12.25.07 @ 16:12pm | #43695
Hi Can someone tell me where the file is stored when you run the upload. I get the message to say it's been uploaded but i can't find the uploaded file anywhere.
Cheers,
Posted by Stu on Monday, 11.19.07 @ 19:57pm | #37841
I cannot find out where the file is getting stored
Posted by PVR on Thursday, 09.27.07 @ 05:08am | #29753
But how to set the path for the file
Posted by unni on Tuesday, 09.18.07 @ 10:01am | #27458