1/*
2 * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24/*
25 * @test
26 * @bug 4393174
27 * @summary Checks that ImageIO.write(..., ..., File) truncates the file
28 */
29
30import java.awt.image.BufferedImage;
31import java.io.File;
32import java.io.FileOutputStream;
33
34import javax.imageio.ImageIO;
35
36public class ImageIOWriteFile {
37
38    public static void main(String[] args) {
39        long length0 = -1L;
40        long length1 = -1L;
41
42        try {
43            BufferedImage bi =
44                new BufferedImage(1, 1, BufferedImage.TYPE_INT_RGB);
45
46            File outFile = File.createTempFile("imageiowritefile", ".tmp");
47
48            // Write image to an empty file
49            outFile.delete();
50            ImageIO.write(bi, "png", outFile);
51            length0 = outFile.length();
52
53            // Write a larger file full of junk
54            outFile.delete();
55            FileOutputStream fos = new FileOutputStream(outFile);
56            for (int i = 0; i < length0*2; i++) {
57                fos.write(1);
58            }
59            fos.close();
60
61            // Write image again
62            ImageIO.write(bi, "png", outFile);
63            length1 = outFile.length();
64
65            outFile.delete();
66        } catch (Exception e) {
67            e.printStackTrace();
68            throw new RuntimeException("Unexpected exception!");
69        }
70
71        if (length0 == 0) {
72            throw new RuntimeException("File length is zero!");
73        }
74        if (length1 != length0) {
75            throw new RuntimeException("File length changed!");
76        }
77    }
78}
79