About signed JAR file

[Sun Kehao]

Hi,who can tell me how to solve my problem?   I know this problem is off-topic, but I need your help.   I use JBuilder1.0( JKD1.1 ). The problem is that I need get some files from Client-side, so I installed Plugin-112i-win32.exe,and I use javakey tool signed my JAR files successfully. I can load applet from Broswer(IE4.0), I can also open a file dialog (by using FileDialog fd = new FileDialog(frame,"load file",FileDialog.LOAD) ), and I can get the correct path and filename,   however I can not read it!   The code is :    try    {      RandomAccessFile file = new RandomAccessFile(filename,"r") ;     int size = (int)file.length() ;     byte[] data = new byte[size] ;     file.readFully(data) ;     file.close() ;    }    catch(Exception e)    {      System.out.println(e.getMessage()) ;    }   The Exception is "checkRead".   How can I solve it? I have spent much time fot it.   Kehao