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Java > Open Source Codes > net > sourceforge > importscrubber > FileChooser


1 package net.sourceforge.importscrubber;
2
3 import java.io.File JavaDoc;
4 import java.io.IOException JavaDoc;
5 import java.util.*;
6
7 // note: could have used threads rather than the iterator approach used here,
8 // but that would have bought us nothing in the command line version (we don't WANT
9 // a thread scrubbing while this finds files, because most disk systems handle
10 // that kind of load very poorly). so since our only concern is allowing the GUI
11 // to update as files are found, this is just as effective -- and simpler.
12
13 public class FileChooser implements Iterator
14 {
15     private String JavaDoc _sourceRoot, _classRoot;
16     private boolean _recurse;
17     // pre-computed for efficiency
18 int relStart;
19
20     private LinkedList possibles = new LinkedList();
21     private FilePair nextFp;
22
23     public FileChooser(String JavaDoc sourceRoot, String JavaDoc classRoot, boolean recurse) throws IOException JavaDoc
24     {
25         File JavaDoc file = new File JavaDoc(sourceRoot);
26         if (!file.exists())
27             throw new IllegalArgumentException JavaDoc(Resources.ERR_DIR_NOT_EXIST);
28         _sourceRoot = file.getCanonicalPath();
29
30         file = new File JavaDoc(classRoot);
31         if (!file.isDirectory())
32             throw new IllegalArgumentException JavaDoc(Resources.ERR_NOT_DIR);
33         if (!file.exists())
34             throw new IllegalArgumentException JavaDoc(Resources.ERR_DIR_NOT_EXIST);
35         _classRoot = file.getCanonicalPath();
36
37         _recurse = recurse;
38
39         relStart = ImportScrubber.getDirectory(_sourceRoot).length();
40
41         possibles.add(_sourceRoot);
42     }
43
44     public void remove
45         ()
46     {
47         throw new UnsupportedOperationException JavaDoc();
48     }
49
50     public boolean hasNext()
51     {
52         if (nextFp == null) {
53             try {
54                 nextFp = (FilePair)next();
55             } catch (NoSuchElementException e) {}
56         }
57         return nextFp != null;
58     }
59
60     public Object JavaDoc next() throws NoSuchElementException
61     {
62         if (nextFp != null) {
63             FilePair f = nextFp;
64             nextFp = null;
65             return f;
66         }
67
68         FilePair fp = null;
69         while (fp == null) {
70             fp = nextPossible();
71         }
72         return fp;
73     }
74
75     // returns null if the sourcefile didn't have a matching classfile.
76 private FilePair nextPossible() throws NoSuchElementException
77     {
78         String JavaDoc s = (String JavaDoc)possibles.removeFirst();
79         File JavaDoc tmp = new File JavaDoc(s);
80         if (tmp.isDirectory()) {
81             if (_recurse) {
82                 String JavaDoc[] entries = tmp.list(new JavaFileFilter());
83                 for (int i = 0; i < entries.length; i++) {
84                     possibles.add(s + ImportScrubber.FILE_SEPARATOR + entries[i]);
85                 }
86             }
87             return nextPossible();
88         } else {
89             return getPair(tmp);
90         }
91     }
92
93     private FilePair getPair(File JavaDoc source)
94     {
95         if (!(source.canRead() && source.canWrite())) {
96             return null;
97         }
98         String JavaDoc relativeSourceFilename = source.getParent().substring(relStart);
99
100         String JavaDoc cfilename = source.getName().substring(0, source.getName().length() - 5) + ".class";
101         String JavaDoc classfilename = _classRoot + relativeSourceFilename + ImportScrubber.FILE_SEPARATOR + cfilename;
102         File JavaDoc classfile = new File JavaDoc(classfilename);
103         if(classfile.exists()) {
104             return new FilePair(source, classfile);
105         }
106
107         return null;
108     }
109 }
110
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