Uploading files using applet to server

[Aruna Velpuri]

Hi
I want to upload a directory from client machine using signed applets to server.
Plz can any one give the solution to my problem.
Thanks in advance

[Manuel Moons]

First u will need something to post the files: (I wrapped them in a zip file) --> the Uploader

  
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.zip.ZipEntry;
public class Uploader {

private String url;

public Uploader(String url) {
this.url = url;
}

public void publish(File[] allfiles) {
try {
//create a temp file for uploading
                       File inputZipFile = File.createTempFile("upload",".zip");
FileOutputStream fos = new FileOutputStream(inputZipFile);
java.util.zip.ZipOutputStream zos = new java.util.zip.ZipOutputStream(fos);

//add all selected file to the zip file
for (int i = 0; i < allfiles.length; i++) {
ZipEntry zipEntry = new ZipEntry(allfiles[i].getName());
zipEntry.setSize(allfiles[i].length());
zos.putNextEntry(zipEntry);
//read the file
FileInputStream fis = new FileInputStream(allfiles[i]);
byte[] inputFile = new byte[fis.available()];
fis.read(inputFile);
zos.write(inputFile);
fis.close();
}
zos.close();
fos.close();

//read the zipfile in memoryFileInputStream fis = new FileInputStream(inputZipFile);
byte[] bytes = new byte[fis.available()];
fis.read(bytes);
fis.close();

//open a connectionHttpURLConnection con =
(HttpURLConnection) new URL(url)
.openConnection();
con.setDoOutput(true);
con.setDoInput(true);
//set http header boundary 
String boundary = "-----------------------------" + ((int)(Math.random() * 100000000));
//different parts in the http request are forwarded by a header//this header contains the type, filename , ...
String header = boundary + "\r\n" + 
"Content-Disposition: form-data; name=\"file1\"; filename=\"upload.zip\"" + "\r\n" +
"Content-Type: application/x-zip-compressed" + "\r\n" + "\r\n";
String footer = "\r\n" + boundary + "--";
con.setRequestMethod("POST");
//request is closed using a footer
con.setRequestProperty("Content-length", String.valueOf(bytes.length + header.length()+ footer.length()));
//fill up the http header
con.setRequestProperty("content-type","multipart/form-data; boundary=" + boundary.substring(2));


// Write the parameters to the URL output stream
OutputStream out = con.getOutputStream();
BufferedOutputStream bos = new BufferedOutputStream(out);
//write the header   bos.write(header.getBytes());
   
   //write the file
bos.write(bytes);

//write the footerbos.write(footer.getBytes());
bos.flush();

// Read the response
BufferedReader in =
new BufferedReader(new InputStreamReader(con.getInputStream()));
while (true) {
String line = in.readLine();
if (line == null)
break;
System.out.println(line);
}
in.close();
out.close();
bos.close();
con.disconnect();

//remove the temp file 
inputZipFile.delete();

} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String args[]) {
try {
File [] fileList = new File("d:\\test\\").listFiles(new BasicFileFilter());
new Uploader("http://127.0.0.1:8080/edisonWeb/UploadServlet").publish(fileList);
}catch(Exception e) {
e.printStackTrace();
}

}
}

Now u will need something to read the file that u send (a Servlet):

 
import java.io.File;
import java.io.IOException;
import java.util.Enumeration;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.struts.upload.MultipartElement;
import org.apache.struts.upload.MultipartIterator;

public class UploadServlet extends HttpServlet {
public void doPost(
javax.servlet.http.HttpServletRequest request,
javax.servlet.http.HttpServletResponse response)
throws javax.servlet.ServletException, java.io.IOException {
doGet(request,response);
}
public void doGet(
javax.servlet.http.HttpServletRequest request,
javax.servlet.http.HttpServletResponse response)
throws javax.servlet.ServletException, java.io.IOException {


String text = null;
try {

/**/


Enumeration enum = request.getHeaderNames();
while(enum.hasMoreElements()) {
String key = (String)enum.nextElement();
System.out.println(key + " === " + request.getHeader(key));
}
MultipartIterator iterator = new MultipartIterator(
request,
request.getContentLength(),
500000,
"c:\\temp\\outputs\\");
MultipartElement mpElement = iterator.getNextElement();

while(mpElement != null) {
if(mpElement.isFile()) {

File tempFile = mpElement.getFile();
//controleer of er wel informatie in de file zit
if(tempFile.length() != 0) {

File resultFile = new File("c:\\temp\\outputs\\" + mpElement.getFileName());
if(resultFile.exists()) {
resultFile.delete();
}

tempFile.renameTo(resultFile);
} else {
//wis de file er zit toch geen informatie in.
tempFile.delete();
}


} else {
text = mpElement.getValue();
System.out.println(mpElement.getName() + " ---> " + mpElement.getValue());
}


mpElement = iterator.getNextElement();
}
/**/
response.getOutputStream().write(("<html><head><title>succes</title></head><body>Het is gelukt:"+text+"</body></html>").getBytes());

}catch(Exception e) {
e.printStackTrace();
}

}
}
 

This should do it.