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1
18 package net.sf.drftpd.util;
19
20 import java.io.File  ;
21 import java.io.FileOutputStream ;
22 import java.io.IOException ;
23 import java.io.OutputStreamWriter ;
24 import java.io.Writer ;
25
26 import org.apache.log4j.Logger;
27
28
32 public class SafeFileWriter extends Writer {
33 private File _actualFile;
34 private OutputStreamWriter _out;
35 private File _tempFile;
36 private boolean failed = false;
37
38
41 public SafeFileWriter(File file) throws IOException {
42 _actualFile = file;
43 if (!_actualFile.getAbsoluteFile().getParentFile().canWrite())
44 throw new IOException ("Can't write to target dir");
45
46 File dir = _actualFile.getParentFile();
47 if(dir == null) dir = new File (".");
48 _tempFile =
49 File.createTempFile(
50 _actualFile.getName(),
51 null,
52 dir);
53 _out = new OutputStreamWriter (new FileOutputStream (_tempFile), "UTF-8");
54 }
55
56
59 public SafeFileWriter(String fileName) throws IOException {
60 this(new File (fileName));
61 }
62
63 public void close() throws IOException {
64 _out.flush();
65 _out.close();
66 if (!failed) {
67 Logger.getLogger(SafeFileWriter.class).debug("Renaming "+_tempFile+" ("+_tempFile.length()+") to "+_actualFile);
68 if (_actualFile.exists() && !_actualFile.delete())
69 throw new IOException ("delete() failed");
70 if (!_tempFile.exists())
71 throw new IOException ("source doesn't exist");
72 if (!_tempFile.renameTo(_actualFile))
73 throw new IOException (
74 "renameTo(" + _tempFile + ", " + _actualFile + ") failed");
75 }
76 }
77
78 public void flush() throws IOException {
79 _out.flush();
80 }
81
82 public void write(char[] cbuf, int off, int len) throws IOException {
83 try {
84 _out.write(cbuf, off, len);
85 } catch (IOException e) {
86 failed = true;
87 throw e;
88 }
89 }
90 }
91 |
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