Commit | Line | Data |
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8e76f6ab | 1 | package be.nikiroo.utils.streams; |
ec1f3444 | 2 | |
7194ac50 | 3 | import java.io.File; |
ec1f3444 | 4 | import java.io.FileInputStream; |
7194ac50 | 5 | import java.io.FileNotFoundException; |
ec1f3444 NR |
6 | import java.io.FilterInputStream; |
7 | import java.io.IOException; | |
8 | import java.nio.channels.FileChannel; | |
9 | ||
10 | /** | |
11 | * This is a markable (and thus reset-able) stream that you can create from a | |
12 | * FileInputStream. | |
13 | * | |
14 | * @author niki | |
15 | */ | |
16 | public class MarkableFileInputStream extends FilterInputStream { | |
17 | private FileChannel channel; | |
18 | private long mark = 0; | |
19 | ||
7194ac50 NR |
20 | /** |
21 | * Create a new {@link MarkableFileInputStream} from this file. | |
22 | * | |
23 | * @param file | |
24 | * the {@link File} to wrap | |
25 | * | |
26 | * @throws FileNotFoundException | |
27 | * if the {@link File} cannot be found | |
28 | */ | |
29 | public MarkableFileInputStream(File file) throws FileNotFoundException { | |
30 | this(new FileInputStream(file)); | |
31 | } | |
32 | ||
ec1f3444 NR |
33 | /** |
34 | * Create a new {@link MarkableFileInputStream} from this stream. | |
35 | * | |
36 | * @param in | |
37 | * the original {@link FileInputStream} to wrap | |
38 | */ | |
39 | public MarkableFileInputStream(FileInputStream in) { | |
40 | super(in); | |
41 | channel = in.getChannel(); | |
42 | } | |
43 | ||
44 | @Override | |
45 | public boolean markSupported() { | |
46 | return true; | |
47 | } | |
48 | ||
49 | @Override | |
50 | public synchronized void mark(int readlimit) { | |
51 | try { | |
52 | mark = channel.position(); | |
53 | } catch (IOException ex) { | |
54 | ex.printStackTrace(); | |
55 | mark = -1; | |
56 | } | |
57 | } | |
58 | ||
59 | @Override | |
60 | public synchronized void reset() throws IOException { | |
61 | if (mark < 0) { | |
62 | throw new IOException("mark position not valid"); | |
63 | } | |
64 | channel.position(mark); | |
65 | } | |
66 | } |