Signed Applet - Problem reading large local files
Hello,
I am using a signed applet (self-signed) to read files from a clients machine (local file system). Following is the code for buffered reading (the meat):
String thisLine, ret = "";
try{
BufferedReader myInput = new BufferedReader(new FileReader(fn));
while ((thisLine = myInput.readLine()) != null) {
ret += thisLine + "\n";
}
myInput.close();
}
catch (Exception e) {
ret = "Cannot load, exception!";
}
When I read a file <= 512KB, it runs fine/as expected. Now, when I read a file, say for example 1024KB in size, I expect the application to take twice as much time (than 512KB file) and read the file, but instead the applet/browser hangs. As a matter of fact I am not able to read files > 512KB.
So, is there a limit on file size (from local file system) when reading from an applet, or is it to do with the way I am reading it?
Any help, suggestions or comments would be highly appreciated.
Thanks in advance.
[1030 byte] By [
saeenalia] at [2007-10-1 0:07:18]
Here is how I read a file from my applet:
private String getData(String u) {
URL url = null;
InputStream in = null;
String ret = null;
try {
// the following line wil read a file @ the same location as your class file
// this way your applet does not need any special privileges
// you could change the url to a file if so needed
url = new URL(this.getCodeBase(), u);
URLConnection conn = url.openConnection();
// next line is optional and just tells the http server
// a utf-8 response is accepted
// some servers will return a bad request
conn.setRequestProperty("Accept-Charset","utf-8");
// first try to find out if the server has
// provided us with the charset of the response
// since this doesn't work with the msjvp (version 1.1.2)
// it's commented out
// instead provide a charEncoding yourselve
String charEncoding = "UTF8";
//int i = conn.getHeaderFields().size()-1;
//while(i>-1){
//System.out.print(conn.getHeaderFieldKey(i));
//System.out.print("=");
//System.out.println(conn.getHeaderField(i));
//if(conn.getHeaderField(i).toLowerCase().indexOf("charset")!=-1){
//String charsetLine = conn.getHeaderField(i).toUpperCase();
//if(charsetLine.indexOf("SHIFT_JIS")!=-1){
//charEncoding = "Shift_JIS";
//}
//if(charsetLine.indexOf("EUC-JP")!=-1){
//charEncoding = "EUC-JP";
//}
//}
//i--;
//}
// here is the value for char encoding (as a parameter in the <object html tag)
if(this.getParameter("dataCharset")!=null){
charEncoding=this.getParameter("dataCharset");
}
// wither you have a file or an url you read from an inputstream
// here is how it's done
// read the whole file and than turn it into a string
in = conn.getInputStream();
ByteArrayOutputStream bos = new ByteArrayOutputStream();
int len;
byte[] buf = new byte[1024];
while ((len = in.read(buf)) > 0) {
bos.write(buf, 0, len);
}
in.close();
// you have the file as a byte array (bos.toByteArray()
// here is how you turn it into a string
ret = new String(bos.toByteArray(),charEncoding);
} catch (Exception e) {
e.printStackTrace(System.out);
}
return ret;
}
