Use this code to change the read-only permissions of a file in JDK 1.2.2:
public void changeFilePermission(){ String osName = System.getProperty("os.name"); try{ if (osName.equalsIgnoreCase("WINDOWS NT") ||osName.equals("Windows 2000") ) { Runtime.getRuntime().exec("cmd.exe /c attrib -r *.*"); }else{ Process Proc = Runtime.getRuntime().exec("command.com /Cattrib -r *.*"); } Thread.currentThread().sleep(100); }catch(Exception e){ System.out.println(e.getMessage()); } }