src/be/nikiroo/utils/NextableInputStream.java

   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 }