jdk/test/javax/imageio/ImageIOWriteFile.java
changeset 45351 f7f615a3aaff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/javax/imageio/ImageIOWriteFile.java	Mon May 22 19:54:23 2017 -0700
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 4393174
+ * @summary Checks that ImageIO.write(..., ..., File) truncates the file
+ */
+
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.FileOutputStream;
+
+import javax.imageio.ImageIO;
+
+public class ImageIOWriteFile {
+
+    public static void main(String[] args) {
+        long length0 = -1L;
+        long length1 = -1L;
+
+        try {
+            BufferedImage bi =
+                new BufferedImage(1, 1, BufferedImage.TYPE_INT_RGB);
+
+            File outFile = File.createTempFile("imageiowritefile", ".tmp");
+
+            // Write image to an empty file
+            outFile.delete();
+            ImageIO.write(bi, "png", outFile);
+            length0 = outFile.length();
+
+            // Write a larger file full of junk
+            outFile.delete();
+            FileOutputStream fos = new FileOutputStream(outFile);
+            for (int i = 0; i < length0*2; i++) {
+                fos.write(1);
+            }
+            fos.close();
+
+            // Write image again
+            ImageIO.write(bi, "png", outFile);
+            length1 = outFile.length();
+
+            outFile.delete();
+        } catch (Exception e) {
+            e.printStackTrace();
+            throw new RuntimeException("Unexpected exception!");
+        }
+
+        if (length0 == 0) {
+            throw new RuntimeException("File length is zero!");
+        }
+        if (length1 != length0) {
+            throw new RuntimeException("File length changed!");
+        }
+    }
+}