FieldTypeAscii.java
/*
* 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.commons.imaging.formats.tiff.fieldtypes;
import java.nio.ByteOrder;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
import org.apache.commons.imaging.ImagingException;
import org.apache.commons.imaging.common.Allocator;
import org.apache.commons.imaging.formats.tiff.TiffField;
public class FieldTypeAscii extends AbstractFieldType {
public FieldTypeAscii(final int type, final String name) {
super(type, name, 1);
}
@Override
public Object getValue(final TiffField entry) {
// According to EXIF specification
// "2 = ASCII An 8-bit byte containing one 7-bit ASCII code. The final byte is terminated with NULL."
final byte[] bytes = entry.getByteArrayValue();
int nullCount = 1;
for (int i = 0; i < bytes.length - 1; i++) {
if (bytes[i] == 0) {
nullCount++;
}
}
final String[] strings = Allocator.array(nullCount, String[]::new, 24);
int stringsAdded = 0;
strings[0] = ""; // if we have a 0 length string
int nextStringPos = 0;
// According to the Exiftool FAQ, [BROKEN URL] http://www.metadataworkinggroup.org
// specifies that the TIFF ASCII fields are actually UTF-8.
// Exiftool however allows you to configure the charset used.
for (int i = 0; i < bytes.length; i++) {
if (bytes[i] == 0) {
final String string = new String(bytes, nextStringPos, i - nextStringPos, StandardCharsets.UTF_8);
strings[stringsAdded++] = string;
nextStringPos = i + 1;
}
}
if (nextStringPos < bytes.length) {
// Buggy file, string wasn't null terminated
final String string = new String(bytes, nextStringPos, bytes.length - nextStringPos, StandardCharsets.UTF_8);
strings[stringsAdded++] = string;
}
if (strings.length == 1) {
return strings[0];
}
return strings;
}
@Override
public byte[] writeData(final Object o, final ByteOrder byteOrder) throws ImagingException {
if (o instanceof byte[]) {
final byte[] bytes = (byte[]) o;
final byte[] result = Arrays.copyOf(bytes, bytes.length + 1);
result[result.length - 1] = 0;
return result;
}
if (o instanceof String) {
final byte[] bytes = ((String) o).getBytes(StandardCharsets.UTF_8);
final byte[] result = Arrays.copyOf(bytes, bytes.length + 1);
result[result.length - 1] = 0;
return result;
}
if (!(o instanceof String[])) {
throw new ImagingException("Unknown data type: " + o);
}
final String[] strings = (String[]) o;
int totalLength = 0;
for (final String string : strings) {
final byte[] bytes = string.getBytes(StandardCharsets.UTF_8);
totalLength += bytes.length + 1;
}
final byte[] result = Allocator.byteArray(totalLength);
int position = 0;
for (final String string : strings) {
final byte[] bytes = string.getBytes(StandardCharsets.UTF_8);
System.arraycopy(bytes, 0, result, position, bytes.length);
position += bytes.length + 1;
}
return result;
}
}