2 * Copyright 2008 ZXing authors
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 package com.google.zxing.oned;
19 import com.google.zxing.BarcodeFormat;
20 import com.google.zxing.ChecksumException;
21 import com.google.zxing.FormatException;
22 import com.google.zxing.NotFoundException;
23 import com.google.zxing.common.BitArray;
26 * <p>Implements decoding of the UPC-E format.</p>
28 * <p><a href="http://www.barcodeisland.com/upce.phtml">This</a> is a great reference for
29 * UPC-E information.</p>
33 public final class UPCEReader extends UPCEANReader {
36 * The pattern that marks the middle, and end, of a UPC-E pattern.
37 * There is no "second half" to a UPC-E barcode.
39 private static final int[] MIDDLE_END_PATTERN = {1, 1, 1, 1, 1, 1};
42 * See {@link #L_AND_G_PATTERNS}; these values similarly represent patterns of
43 * even-odd parity encodings of digits that imply both the number system (0 or 1)
44 * used, and the check digit.
46 private static final int[][] NUMSYS_AND_CHECK_DIGIT_PATTERNS = {
47 {0x38, 0x34, 0x32, 0x31, 0x2C, 0x26, 0x23, 0x2A, 0x29, 0x25},
48 {0x07, 0x0B, 0x0D, 0x0E, 0x13, 0x19, 0x1C, 0x15, 0x16, 0x1A}
51 private final int[] decodeMiddleCounters;
54 decodeMiddleCounters = new int[4];
57 protected int decodeMiddle(BitArray row, int[] startRange, StringBuffer result)
58 throws NotFoundException {
59 int[] counters = decodeMiddleCounters;
64 int end = row.getSize();
65 int rowOffset = startRange[1];
67 int lgPatternFound = 0;
69 for (int x = 0; x < 6 && rowOffset < end; x++) {
70 int bestMatch = decodeDigit(row, counters, rowOffset, L_AND_G_PATTERNS);
71 result.append((char) ('0' + bestMatch % 10));
72 for (int i = 0; i < counters.length; i++) {
73 rowOffset += counters[i];
75 if (bestMatch >= 10) {
76 lgPatternFound |= 1 << (5 - x);
80 determineNumSysAndCheckDigit(result, lgPatternFound);
85 protected int[] decodeEnd(BitArray row, int endStart) throws NotFoundException {
86 return findGuardPattern(row, endStart, true, MIDDLE_END_PATTERN);
89 protected boolean checkChecksum(String s) throws FormatException, ChecksumException {
90 return super.checkChecksum(convertUPCEtoUPCA(s));
93 private static void determineNumSysAndCheckDigit(StringBuffer resultString, int lgPatternFound)
94 throws NotFoundException {
96 for (int numSys = 0; numSys <= 1; numSys++) {
97 for (int d = 0; d < 10; d++) {
98 if (lgPatternFound == NUMSYS_AND_CHECK_DIGIT_PATTERNS[numSys][d]) {
99 resultString.insert(0, (char) ('0' + numSys));
100 resultString.append((char) ('0' + d));
105 throw NotFoundException.getNotFoundInstance();
108 BarcodeFormat getBarcodeFormat() {
109 return BarcodeFormat.UPC_E;
113 * Expands a UPC-E value back into its full, equivalent UPC-A code value.
115 * @param upce UPC-E code as string of digits
116 * @return equivalent UPC-A code as string of digits
118 public static String convertUPCEtoUPCA(String upce) {
119 char[] upceChars = new char[6];
120 upce.getChars(1, 7, upceChars, 0);
121 StringBuffer result = new StringBuffer(12);
122 result.append(upce.charAt(0));
123 char lastChar = upceChars[5];
128 result.append(upceChars, 0, 2);
129 result.append(lastChar);
130 result.append("0000");
131 result.append(upceChars, 2, 3);
134 result.append(upceChars, 0, 3);
135 result.append("00000");
136 result.append(upceChars, 3, 2);
139 result.append(upceChars, 0, 4);
140 result.append("00000");
141 result.append(upceChars[4]);
144 result.append(upceChars, 0, 5);
145 result.append("0000");
146 result.append(lastChar);
149 result.append(upce.charAt(7));
150 return result.toString();