| 1 | package be.nikiroo.utils.streams; |
| 2 | |
| 3 | import java.io.IOException; |
| 4 | import java.io.OutputStream; |
| 5 | |
| 6 | /** |
| 7 | * This {@link OutputStream} will change some of its content by replacing it |
| 8 | * with something else. |
| 9 | * |
| 10 | * @author niki |
| 11 | */ |
| 12 | public class ReplaceOutputStream extends BufferedOutputStream { |
| 13 | private byte[] from; |
| 14 | private byte[] to; |
| 15 | |
| 16 | /** |
| 17 | * Create a {@link ReplaceOutputStream} that will replace <tt>from</tt> with |
| 18 | * <tt>to</tt>. |
| 19 | * |
| 20 | * @param out |
| 21 | * the under-laying {@link OutputStream} |
| 22 | * @param from |
| 23 | * the {@link String} to replace |
| 24 | * @param to |
| 25 | * the {@link String} to replace with |
| 26 | */ |
| 27 | public ReplaceOutputStream(OutputStream out, String from, String to) { |
| 28 | this(out, StreamUtils.bytes(from), StreamUtils.bytes(to)); |
| 29 | } |
| 30 | |
| 31 | /** |
| 32 | * Create a {@link ReplaceOutputStream} that will replace <tt>from</tt> with |
| 33 | * <tt>to</tt>. |
| 34 | * |
| 35 | * @param out |
| 36 | * the under-laying {@link OutputStream} |
| 37 | * @param from |
| 38 | * the value to replace |
| 39 | * @param to |
| 40 | * the value to replace with |
| 41 | */ |
| 42 | public ReplaceOutputStream(OutputStream out, byte[] from, byte[] to) { |
| 43 | super(out); |
| 44 | bypassFlush = false; |
| 45 | |
| 46 | this.from = from; |
| 47 | this.to = to; |
| 48 | } |
| 49 | |
| 50 | @Override |
| 51 | protected void flush(boolean includingSubStream) throws IOException { |
| 52 | // Note: very simple, not efficient implementation, sorry. |
| 53 | while (start < stop) { |
| 54 | if (from.length > 0 |
| 55 | && StreamUtils.startsWith(from, buffer, start, stop)) { |
| 56 | out.write(to); |
| 57 | bytesWritten += to.length; |
| 58 | start += from.length; |
| 59 | } else { |
| 60 | out.write(buffer[start++]); |
| 61 | bytesWritten++; |
| 62 | } |
| 63 | } |
| 64 | |
| 65 | start = 0; |
| 66 | stop = 0; |
| 67 | |
| 68 | if (includingSubStream) { |
| 69 | out.flush(); |
| 70 | } |
| 71 | } |
| 72 | } |