How to use

canWrite

method

in

javax.jnlp.FileContents

@Override
public OutputStream openOutputFile(String fileName, boolean append) throws IOException {
  checkBasics("openOutputFile");
  URL fileURL = fileNameToURL(fileName);
  try {
    FileContents fc = null;
    try {
      fc = ps.get(fileURL);
    } catch (FileNotFoundException e) {
      /* Verify that the max size for new PersistenceService
       * files is >= 100K (2^17) before opening one.
       */
      long maxSizeRequest = 131072L;
      long maxSize = ps.create(fileURL, maxSizeRequest);
      if (maxSize >= maxSizeRequest) {
        fc = ps.get(fileURL);
      }
    }
    if ((fc != null) && (fc.canWrite())) {
      return new BufferedOutputStream(fc.getOutputStream(!append));
    } else {
      throw new IOException("unable to create FileContents object");
    }
  } catch (Exception e) {
    throw new IOException("openOutputFile \"" + fileName + "\" failed", e);
  }
}

public OutputStream openOutputFile(String fileName) throws IOException {
  checkBasics("openOutputFile");
  URL fileURL = fileNameToURL(fileName);
  try {
  FileContents fc = null;
  try {
    fc = ps.get(fileURL);  
  }
  catch (FileNotFoundException e) {
    /* Verify that the max size for new PersistenceService 
     * files is >= 100K (2^17) before opening one.
     */
    long maxSizeRequest = 131072L;
    long maxSize = ps.create(fileURL, maxSizeRequest);
    if (maxSize >= maxSizeRequest) {
    fc = ps.get(fileURL);
    }
  }
  if ((fc != null) && (fc.canWrite())) {
    return new BufferedOutputStream(fc.getOutputStream(true));
  }
  else {
    throw new IOException("unable to create FileContents object");
  }
  } 
  catch(Exception e) {
  throw new LSException("openOutputFile \"" + fileName + "\" failed", e);
  }
}