Examples of java.nio.channels.FileChannel.truncate()

java.nio.channels.FileChannel.truncate()
Truncates the file underlying this channel to a given size.
Any bytes beyond the given size are removed from the file. If there are no bytes beyond the given size then the file contents are unmodified.

If the file position is currently greater than the given size, then it is set to be the given size.
@param size the maximum size of the underlying file @throws IllegalArgumentException the requested size is negative. @throws ClosedChannelException the channel is closed. @throws NonWritableChannelException the channel cannot be written. @throws IOException some other IO problem occured. @return this channel

        FileOutputStream fos = new FileOutputStream(out);
        
        FileChannel readableChannel = fis.getChannel();
        FileChannel writableChannel = fos.getChannel();
        
        writableChannel.truncate(0);
        writableChannel.transferFrom(readableChannel, 0, readableChannel.size());
        fis.close();
        fos.close();
        return true;
      }

View Full Code Here

      FileOutputStream outputStream = new FileOutputStream(targetFile);


      FileChannel readableChannel = inputStream.getChannel();
      FileChannel writableChannel = outputStream.getChannel();


      writableChannel.truncate(0);
      writableChannel.transferFrom(
        readableChannel, 0, readableChannel.size());
      inputStream.close();
      outputStream.close();
    } catch (IOException ioException) {

View Full Code Here

      FileOutputStream outputStream = new FileOutputStream(targetFile);


      FileChannel readableChannel = inputStream.getChannel();
      FileChannel writableChannel = outputStream.getChannel();


      writableChannel.truncate(0);
      writableChannel.transferFrom(
        readableChannel, 0, readableChannel.size());
      inputStream.close();
      outputStream.close();
    } catch (IOException ioException) {

View Full Code Here

    FileChannel outChan;
    try {
      outChan = new FileOutputStream(
          new File(IConstants.CITY_CONFIG_FILE), true).getChannel();


      outChan.truncate(0);
      outChan.close();


    } catch (FileNotFoundException e) {
      log.error(e, e);
      return;

View Full Code Here

        FileUtils.createDirectories(getBaseDir() + "/fs");
        FileChannel c = FileUtils.open(f, "rw");
        c.position(4000);
        c.write(ByteBuffer.wrap(new byte[1]));
        FileLock lock = c.tryLock();
        c.truncate(0);
        if (lock != null) {
            lock.release();
        }
        c.close();
    }

View Full Code Here

                    ra.write(buffer, 0, buffer.length);
                    break;
                }
                case 2: {
                    trace("truncate " + pos);
                    f.truncate(pos);
                    if (pos < ra.length()) {
                        // truncate is supposed to have no effect if the
                        // position is larger than the current size
                        ra.setLength(pos);
                    }

View Full Code Here

            target.createNewFile();
        } else if (endpoint.getFileExist() == GenericFileExist.Override) {
            LOG.debug("Truncating existing file: {}", target);
            FileChannel out = new FileOutputStream(target).getChannel();
            try {
                out.truncate(0);
            } finally {
                IOHelper.force(out, target.getName(), LOG);
                IOHelper.close(out, target.getName(), LOG);
            }
        }

View Full Code Here

            Object value = attributes.get(attribute);
            switch (attribute) {
                case Size:             {
                    long newSize = (Long) value;
                    FileChannel outChan = new FileOutputStream(file, true).getChannel();
                    outChan.truncate(newSize);
                    outChan.close();
                    continue;
                }
                case Uid:              name = "unix:uid"; break;
                case Owner:            name = "unix:owner"; value = toUser((String) value); break;

View Full Code Here

            fileChannel.position(fileChannel.size());
            // FIXME: This worries me a bit, since it could allocate a lot with a large newLength
            fileChannel.write(ByteBuffer.allocate(difference));
            fileChannel.position(position);
        } else {
            fileChannel.truncate(newLength);
        }
    }


    /**
     * Invalidate buffer before a position change has occurred (e.g. seek),

View Full Code Here

            leftSize = r.nextInt(headerLen);
        } else {
            leftSize = headerLen + r.nextInt(1024 - headerLen);
        }
        FileChannel fc = new RandomAccessFile(fn, "rw").getChannel();
        fc.truncate(leftSize);
        fc.close();
    }


    /**
     * Generate meta entry with given master key

View Full Code Here

0 1 2 3 4 5 6 7 8 9

TOP

All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.