Add support encoding UPC-E format

core/src/main/java/com/google/zxing/MultiFormatWriter.java

@@ -26,6 +26,7 @@ import com.google.zxing.oned.EAN13Writer;
 import com.google.zxing.oned.EAN8Writer;
 import com.google.zxing.oned.ITFWriter;
 import com.google.zxing.oned.UPCAWriter;
+import com.google.zxing.oned.UPCEWriter;
 import com.google.zxing.pdf417.PDF417Writer;
 import com.google.zxing.qrcode.QRCodeWriter;
 
@@ -58,6 +59,9 @@ public final class MultiFormatWriter implements Writer {
       case EAN_8:
         writer = new EAN8Writer();
         break;
+      case UPC_E:
+        writer = new UPCEWriter();
+        break;
       case EAN_13:
         writer = new EAN13Writer();
         break;

core/src/main/java/com/google/zxing/oned/UPCEANReader.java

@@ -56,7 +56,10 @@ public abstract class UPCEANReader extends OneDReader {
    * Pattern marking the middle of a UPC/EAN pattern, separating the two halves.
    */
   static final int[] MIDDLE_PATTERN = {1, 1, 1, 1, 1};
-
+  /**
+   * end guard pattern.
+   */
+  static final int[] END_PATTERN = {1, 1, 1, 1, 1, 1};
   /**
    * "Odd", or "L" patterns used to encode UPC/EAN digits.
    */

core/src/main/java/com/google/zxing/oned/UPCEReader.java

@@ -29,7 +29,32 @@ import com.google.zxing.common.BitArray;
  * @author Sean Owen
  */
 public final class UPCEReader extends UPCEANReader {
-
+  // For an UPC-E barcode, the final digit is represented by the parities used
+  // to encode the middle six digits, according to the table below.
+  //
+  //                Parity of next 6 digits
+  //    Digit   0     1     2     3     4     5
+  //       0    Even   Even  Even Odd  Odd   Odd
+  //       1    Even   Even  Odd  Even Odd   Odd
+  //       2    Even   Even  Odd  Odd  Even  Odd
+  //       3    Even   Even  Odd  Odd  Odd   Even
+  //       4    Even   Odd   Even Even Odd   Odd
+  //       5    Even   Odd   Odd  Even Even  Odd
+  //       6    Even   Odd   Odd  Odd  Even  Even
+  //       7    Even   Odd   Even Odd  Even  Odd
+  //       8    Even   Odd   Even Odd  Odd   Even
+  //       9    Even   Odd   Odd  Even Odd   Even
+  //
+  // The encoding is represented by the following array, which is a bit pattern
+  // using Odd = 0 and Even = 1. For example, 5 is represented by:
+  //
+  //              Odd Even Even Odd Odd Even
+  // in binary:
+  //                0    1    1   0   0    1   == 0x19
+  //
+  static final int[] CHECK_DIGIT_ENCODINGS = {
+      0x38, 0x34, 0x32, 0x31, 0x2C, 0x26, 0x23, 0x2A, 0x29, 0x25
+  };
   /**
    * The pattern that marks the middle, and end, of a UPC-E pattern.
    * There is no "second half" to a UPC-E barcode.

core/src/main/java/com/google/zxing/oned/UPCEWriter.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2009 ZXing authors
+ *
+ * Licensed 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 com.google.zxing.oned;
+
+import java.util.Map;
+
+import com.google.zxing.BarcodeFormat;
+import com.google.zxing.EncodeHintType;
+import com.google.zxing.WriterException;
+import com.google.zxing.common.BitMatrix;
+
+/**
+ * This object renders an UPC-E code as a {@link BitMatrix}.
+ *
+ * @author 0979097955s@gmail.com (RX)
+ */
+public final class UPCEWriter extends UPCEANWriter {
+
+  private static final int CODE_WIDTH = 3 + // start guard
+      (7 * 6) + // bars
+      6; // end guard
+
+  @Override
+  public BitMatrix encode(String contents,
+                          BarcodeFormat format,
+                          int width,
+                          int height,
+                          Map<EncodeHintType, ?> hints) throws WriterException {
+    if (format != BarcodeFormat.UPC_E) {
+      throw new IllegalArgumentException("Can only encode UPC_E, but got " + format);
+    }
+
+    return super.encode(contents, format, width, height, hints);
+  }
+
+  @Override
+  public boolean[] encode(String contents) {
+    if (contents.length() != 8) {
+      throw new IllegalArgumentException(
+        "Requested contents should be 8 digits long, but got " + contents.length());
+    }
+      
+    int checkDigit = Integer.parseInt(contents.substring(7, 8));
+    int parities = UPCEReader.CHECK_DIGIT_ENCODINGS[checkDigit];
+    boolean[] result = new boolean[CODE_WIDTH];
+    int pos = 0;
+
+    pos += appendPattern(result, pos, UPCEANReader.START_END_PATTERN, true);
+
+    for (int i = 1; i <= 6; i++) {
+      int digit = Integer.parseInt(contents.substring(i, i + 1));
+      if ((parities >> (6 - i) & 1) == 1) {
+        digit += 10;
+      }
+      pos += appendPattern(result, pos, UPCEANReader.L_AND_G_PATTERNS[digit], false);
+    }
+
+    appendPattern(result, pos, UPCEANReader.END_PATTERN, false);
+
+    return result;
+  }
+  
+}