| 1 | package be.nikiroo.utils; |
| 2 | |
| 3 | import java.io.IOException; |
| 4 | import java.io.InputStream; |
| 5 | |
| 6 | public class NextableInputStream extends InputStream { |
| 7 | private InputStream in; |
| 8 | private boolean eof; |
| 9 | private int pos = 0; |
| 10 | private int len = 0; |
| 11 | private byte[] buffer = new byte[4096]; |
| 12 | |
| 13 | public NextableInputStream(InputStream in) { |
| 14 | this.in = in; |
| 15 | } |
| 16 | |
| 17 | @Override |
| 18 | public int read() throws IOException { |
| 19 | preRead(); |
| 20 | if (eof) { |
| 21 | return -1; |
| 22 | } |
| 23 | |
| 24 | return buffer[pos++]; |
| 25 | } |
| 26 | |
| 27 | @Override |
| 28 | public int read(byte[] b) throws IOException { |
| 29 | return read(b, 0, b.length); |
| 30 | } |
| 31 | |
| 32 | @Override |
| 33 | public int read(byte[] b, int boff, int blen) throws IOException { |
| 34 | if (b == null) { |
| 35 | throw new NullPointerException(); |
| 36 | } else if (boff < 0 || blen < 0 || blen > b.length - boff) { |
| 37 | throw new IndexOutOfBoundsException(); |
| 38 | } else if (blen == 0) { |
| 39 | return 0; |
| 40 | } |
| 41 | |
| 42 | int done = 0; |
| 43 | while (!eof && done < blen) { |
| 44 | preRead(); |
| 45 | for (int i = pos; i < blen && i < len; i++) { |
| 46 | b[boff + done] = buffer[i]; |
| 47 | pos++; |
| 48 | done++; |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | return done > 0 ? done : -1; |
| 53 | } |
| 54 | |
| 55 | private void preRead() throws IOException { |
| 56 | if (in != null && !eof && pos >= len) { |
| 57 | pos = 0; |
| 58 | len = in.read(buffer); |
| 59 | // checkNexts(); |
| 60 | } |
| 61 | |
| 62 | if (pos >= len) { |
| 63 | eof = true; |
| 64 | } |
| 65 | } |
| 66 | } |