From 65cce551dec95a11c65b76ddabb7905ce9d1b100 Mon Sep 17 00:00:00 2001 From: Luke Quinane Date: Mon, 18 Jun 2012 14:05:38 +1000 Subject: [PATCH] Improve HSLF handling of PNG files. Fix HSSF and HWPF when reading PNGs with a 16 byte header. --- .../apache/poi/hssf/usermodel/HSSFPictureData.java | 14 +++++- src/java/org/apache/poi/util/PngUtils.java | 57 ++++++++++++++++++++ .../src/org/apache/poi/hslf/blip/PNG.java | 30 +++++------ .../src/org/apache/poi/hwpf/usermodel/Picture.java | 10 ++++ 4 files changed, 94 insertions(+), 17 deletions(-) create mode 100644 src/java/org/apache/poi/util/PngUtils.java diff --git a/src/java/org/apache/poi/hssf/usermodel/HSSFPictureData.java b/src/java/org/apache/poi/hssf/usermodel/HSSFPictureData.java index 0516ccc..69bdae1 100644 --- a/src/java/org/apache/poi/hssf/usermodel/HSSFPictureData.java +++ b/src/java/org/apache/poi/hssf/usermodel/HSSFPictureData.java @@ -22,6 +22,7 @@ import org.apache.poi.ddf.EscherBitmapBlip; import org.apache.poi.ddf.EscherBlipRecord; import org.apache.poi.ddf.EscherMetafileBlip; import org.apache.poi.ss.usermodel.PictureData; +import org.apache.poi.util.PngUtils; /** * Represents binary data stored in the file. Eg. A GIF, JPEG etc... @@ -60,7 +61,18 @@ public class HSSFPictureData implements PictureData */ public byte[] getData() { - return blip.getPicturedata(); + byte[] pictureData = blip.getPicturedata(); + + //PNG created on MAC may have a 16-byte prefix which prevents successful reading. + //Just cut it off!. + if (PngUtils.matchesPngHeader(pictureData, 16)) + { + byte[] png = new byte[pictureData.length-16]; + System.arraycopy(pictureData, 16, png, 0, png.length); + pictureData = png; + } + + return pictureData; } /** diff --git a/src/java/org/apache/poi/util/PngUtils.java b/src/java/org/apache/poi/util/PngUtils.java new file mode 100644 index 0000000..0ecb062 --- /dev/null +++ b/src/java/org/apache/poi/util/PngUtils.java @@ -0,0 +1,57 @@ +/* ==================================================================== + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +==================================================================== */ + +package org.apache.poi.util; + +import java.io.ByteArrayOutputStream; +import java.io.IOException; +import java.io.InputStream; +import java.io.OutputStream; + +public final class PngUtils { + + /** + * File header for PNG format. + */ + private static final byte[] PNG_FILE_HEADER = + new byte[] { (byte) 0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A }; + + private PngUtils() { + // no instances of this class + } + + /** + * Checks if the offset matches the PNG header. + * + * @param data the data to check. + * @param offset the offset to check at. + * @return {@code true} if the offset matches. + */ + public static boolean matchesPngHeader(byte[] data, int offset) { + if (data == null || data.length - offset < PNG_FILE_HEADER.length) { + return false; + } + + for (int i = 0; i < PNG_FILE_HEADER.length; i++) { + if (PNG_FILE_HEADER[i] != data[i + offset]) { + return false; + } + } + + return true; + } +} diff --git a/src/scratchpad/src/org/apache/poi/hslf/blip/PNG.java b/src/scratchpad/src/org/apache/poi/hslf/blip/PNG.java index 20016fd..12b98f1 100644 --- a/src/scratchpad/src/org/apache/poi/hslf/blip/PNG.java +++ b/src/scratchpad/src/org/apache/poi/hslf/blip/PNG.java @@ -17,6 +17,7 @@ package org.apache.poi.hslf.blip; +import org.apache.poi.util.PngUtils; import org.apache.poi.hslf.model.Picture; import org.apache.poi.hslf.exceptions.HSLFException; @@ -35,22 +36,19 @@ public final class PNG extends Bitmap { /** * @return PNG data */ - public byte[] getData(){ - byte[] data = super.getData(); - try { - //PNG created on MAC may have a 16-byte prefix which prevents successful reading. - //Just cut it off!. - BufferedImage bi = ImageIO.read(new ByteArrayInputStream(data)); - if (bi == null){ - byte[] png = new byte[data.length-16]; - System.arraycopy(data, 16, png, 0, png.length); - data = png; - } - } catch (IOException e){ - throw new HSLFException(e); - } - return data; - } + public byte[] getData() { + byte[] data = super.getData(); + + //PNG created on MAC may have a 16-byte prefix which prevents successful reading. + //Just cut it off!. + if (PngUtils.matchesPngHeader(data, 16)) { + byte[] png = new byte[data.length-16]; + System.arraycopy(data, 16, png, 0, png.length); + data = png; + } + + return data; + } /** * @return type of this picture diff --git a/src/scratchpad/src/org/apache/poi/hwpf/usermodel/Picture.java b/src/scratchpad/src/org/apache/poi/hwpf/usermodel/Picture.java index ff7af7c..670755d 100644 --- a/src/scratchpad/src/org/apache/poi/hwpf/usermodel/Picture.java +++ b/src/scratchpad/src/org/apache/poi/hwpf/usermodel/Picture.java @@ -34,6 +34,7 @@ import org.apache.poi.ddf.EscherProperty; import org.apache.poi.ddf.EscherRecord; import org.apache.poi.hwpf.model.PICF; import org.apache.poi.hwpf.model.PICFAndOfficeArtData; +import org.apache.poi.util.PngUtils; import org.apache.poi.util.POILogFactory; import org.apache.poi.util.POILogger; import org.apache.poi.util.StringUtil; @@ -191,6 +192,15 @@ public final class Picture { // Raw data is not compressed. content = rawContent; + + //PNG created on MAC may have a 16-byte prefix which prevents successful reading. + //Just cut it off!. + if (PngUtils.matchesPngHeader(content, 16)) + { + byte[] png = new byte[content.length-16]; + System.arraycopy(content, 16, png, 0, png.length); + content = png; + } } } -- 1.7.4.msysgit.0.173.g83185.dirty