I need to implement a way to UPLOAD a file using a POST request. I found a bunch of info on how to handle it in a servlet but nothing for how to simply upload a file from a regular application? It can't be too hard and there seems to be some info about it but not code snippets to help me along. Does anyone know how to go about writing a simple little example using a URL (and associated connection) to do this?
jsp file upload code (any type of file): (fileUpload.jsp)
<%@ page import="java.io.*,javax.servlet.http.HttpServletRequest,javax.servlet.ServletInputStream" %>
<%@ page import="java.io.FileWriter,java.io.IOException" %>
<%
String savePath = "", filepath = "", filename = "";
String contentType = "", fileData = "", strLocalFileName = "";
int startPos = 0;
int endPos = 0;
%>
<%!
//copy specified number of bytes from main data buffer to temp data buffer
void copyByte(byte [] fromBytes, byte [] toBytes, int start, int len)
{
for(int i=start;i<(start+len);i++)
{
toBytes[i - start] = fromBytes[i];
}
}
%>
<%
int BOF = 0, EOF = 0;
contentType = request.getContentType();
out.println("<br>Content type is :: " +contentType);
if ((contentType != null) && (contentType.indexOf("multipart/form-data") >= 0))
{
DataInputStream in = new DataInputStream(request.getInputStream());
DataInputStream in1 = in;
int formDataLength = request.getContentLength();
byte dataBytes[] = new byte[formDataLength];
int byteRead = 0;
int totalBytesRead = 0;
while (totalBytesRead < formDataLength)
{
byteRead = in1.read(dataBytes, totalBytesRead, formDataLength);
totalBytesRead += byteRead;
}
out.println("<br>totalBytesRead : " + totalBytesRead + ":formDataLength = " + formDataLength);
//String file = new String(dataBytes);
//out.println("<br>File Contents:<br>////////////////////////////////////<br>" + file + "<br>////////////////////////////////<br>");
byte[] line = new byte[128];
if (totalBytesRead < 3)
{
return;//exit if file length is not sufficiently large
}
String boundary = "";
String s = "";
int count = 0;
int pos = 0;
//loop for extracting boundry of file
//could also be extracted from request.getContentType()
do
{
copyByte(dataBytes, line, count ,1);//read 1 byte at a time
count+=1;
s = new String(line, 0, 1);
fileData = fileData + s;
pos = fileData.indexOf("Content-Disposition: form-data; name=\""); //set the file name
if(pos != -1)
endPos = pos;
}while(pos == -1);
boundary = fileData.substring(startPos, endPos);
//loop for extracting filename
startPos = endPos;
do
{
copyByte(dataBytes, line, count ,1);//read 1 byte at a time
count+=1;
s = new String(line, 0, 1);
fileData = fileData + s;
pos = fileData.indexOf("filename=\"", startPos); //set the file name
if(pos != -1)
startPos = pos;
}while(pos == -1);
do
{
copyByte(dataBytes, line, count ,1);//read 1 byte at a time
count+=1;
s = new String(line, 0, 1);
fileData = fileData + s;
pos = fileData.indexOf("Content-Type: ", startPos);
if(pos != -1)
endPos = pos;
}while(pos == -1);
filename = fileData.substring(startPos + 10, endPos - 3);//to eliminate " from start & end
strLocalFileName = filename;
int index = filename.lastIndexOf("\\");
if(index != -1)
filename = filename.substring(index + 1);
else
filename = filename;
//loop for extracting ContentType
boolean blnNewlnFlag = false;
startPos = endPos;//added length of "Content-Type: "
do
{
copyByte(dataBytes, line, count ,1);//read 1 byte at a time
count+=1;
s = new String(line, 0, 1);
fileData = fileData + s;
pos = fileData.indexOf("\n", startPos);
if(pos != -1)
{
if(blnNewlnFlag == true)
endPos = pos;
else
{
blnNewlnFlag = true;
pos = -1;
}
}
}while(pos == -1);
contentType = fileData.substring(startPos + 14, endPos);
//loop for extracting actual file data (any type of file)
startPos = count + 1;
do
{
copyByte(dataBytes, line, count ,1);//read 1 byte at a time
count+=1;
s = new String(line, 0, 1);
fileData = fileData + s;
pos = fileData.indexOf(boundary, startPos);//check for end of file data i.e boundry value
}while(pos == -1);
endPos = count - boundary.length();
//file data extracted
out.println("<br><br>0. Local File Name = " + strLocalFileName);
out.println("<br><br>1. filename = " + filename);
out.println("<br>2. contentType = " + contentType);
out.println("<br>3. startPos = " + startPos);
out.println("<br>4. endPos = " + endPos);
out.println("<br>5. boundary = " + boundary);
//create destination path & save file there
String appPath = application.getRealPath("/");
out.println("<br>appPath : " + appPath);
String destFolder = appPath + "images/banner/";
filename= destFolder + filename;
FileOutputStream fileOut = new FileOutputStream(filename);
fileOut.write(dataBytes, startPos, (endPos - startPos));
fileOut.flush();
fileOut.close();
out.println("<br>File saved as >> " + filename);
//file saved at destination
//out.println("<br>File data : <br><br>**************************<br>" + (new String(dataBytes,startPos, (endPos - startPos))) + "<br><br>**************************");
}
else
{
out.println("Error in uploading ");
}
%>
supporting html file:
<form method="post" action="fileUpload.jsp" name="upform" enctype="multipart/form-data">
<table width="60%" border="0" cellspacing="1" cellpadding="1" align="center" class="style1">
<tr>
<td align="left"><b>Select a file to upload :</b></td>
</tr>
<tr>
<td align="left">
<input type="file" name="uploadfile" size="50">
</td>
</tr>
<tr>
<td align="left">
<input type="hidden" name="todo" value="upload">
<input type="submit" name="Submit" value="Upload">
<input type="reset" name="Reset" value="Cancel">
</td>
</tr>
</table>
</form>
</body>
</html>
