Android解决Zxing识别GBK类型二维码出现乱码的问题（效果图对比）

最近在研究二维码识别，用了Zxing的开源代码，但识别GBK类型老是出现乱码。折腾了两天，今天终于解决了，小记一下，。

我是在Zxing-1.6基础上开发的，因为zxing1.6对竖屏要支持好一些。

首先要搭建编译core.jar的环境，这个我就不多说了，不会的话可以参考

主要是改源码部分

修改core\src\com\google\zxing\common StringUtils.java文件

1、在private static final String ISO88591 = "ISO8859_1";下面一行添加

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private static final String GBK = "GB2312";
2、在boolean canBeUTF8 = true;下面添加

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boolean canBeGBK = true;

2、在 int value = bytes[i] & 0xFF;下面开始添加

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//GBK stuff
if (value > 0x7F)// 如果大于127，则可能是GB2312，就开始判断该字节，和下一个字节
{
if (value > 0xB0 && value <= 0xF7)// 第一个字节再此范围内，则开始判断第二个自己
{
    int value2 = bytes[i + 1] & 0xFF;
          if (value2 > 0xA0 && value2 <= 0xF7)
          {
              canBeGBK = true;
          }
}
}

3、在 if (canBeShiftJIS && (maybeDoubleByteCount >= 3 || 20 * maybeSingleByteKatakanaCount > length)) {
return SHIFT_JIS;
}下面添加

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if(canBeGBK){
return GBK;
}

再ant生产core.jar替换之前的就可以了，基本都是依葫芦画瓢，大家应该看得懂，

最后我把完整的StringUtils.java代码放上来，可以对比着看

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/*
* Copyright (C) 2010 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
*
*        * 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.common;

import java.util.Hashtable;

import com.google.zxing.DecodeHintType;

/**
* Common string-related functions.
*
* @author Sean Owen
*/
public final class StringUtils {

private static final String PLATFORM_DEFAULT_ENCODING =
      System.getProperty("file.encoding");
public static final String SHIFT_JIS = "SJIS";
private static final String EUC_JP = "EUC_JP";
private static final String UTF8 = "UTF8";
private static final String ISO88591 = "ISO8859_1";
   private static final String GBK = "GB2312";
private static final boolean ASSUME_SHIFT_JIS =
      SHIFT_JIS.equalsIgnoreCase(PLATFORM_DEFAULT_ENCODING) ||
      EUC_JP.equalsIgnoreCase(PLATFORM_DEFAULT_ENCODING);

private StringUtils() {}

/**
   * @param bytes bytes encoding a string, whose encoding should be guessed
   * @param hints decode hints if applicable
   * @return name of guessed encoding; at the moment will only guess one of:
   * {@link #SHIFT_JIS}, {@link #UTF8}, {@link #ISO88591}, or the platform
   * default encoding if none of these can possibly be correct
   */
public static String guessEncoding(byte[] bytes, Hashtable hints) {
    if (hints != null) {
      String characterSet = (String) hints.get(DecodeHintType.CHARACTER_SET);
      if (characterSet != null) {
        return characterSet;
      }
    }


    // Does it start with the UTF-8 byte order mark? then guess it's UTF-8
    if (bytes.length > 3 &&
        bytes[0] == (byte) 0xEF &&
        bytes[1] == (byte) 0xBB &&
        bytes[2] == (byte) 0xBF) {
      return UTF8;
    }
    // For now, merely tries to distinguish ISO-8859-1, UTF-8 and Shift_JIS,
    // which should be by far the most common encodings. ISO-8859-1
    // should not have bytes in the 0x80 - 0x9F range, while Shift_JIS
    // uses this as a first byte of a two-byte character. If we see this
    // followed by a valid second byte in Shift_JIS, assume it is Shift_JIS.
    // If we see something else in that second byte, we'll make the risky guess
    // that it's UTF-8.
    int length = bytes.length;
    boolean canBeISO88591 = true;
    boolean canBeShiftJIS = true;
    boolean canBeUTF8 = true;
    boolean canBeGBK = true;
    int utf8BytesLeft = 0;
    int maybeDoubleByteCount = 0;
    int maybeSingleByteKatakanaCount = 0;
    boolean sawLatin1Supplement = false;
    boolean sawUTF8Start = false;
    boolean lastWasPossibleDoubleByteStart = false;

    for (int i = 0;
         i < length && (canBeISO88591 || canBeShiftJIS || canBeUTF8 || canBeGBK);
         i++) {

      int value = bytes[i] & 0xFF;

      //GBK stuff
      if (value > 0x7F)// 如果大于127，则可能是GB2312，就开始判断该字节，和下一个字节
      {
        if (value > 0xB0 && value <= 0xF7)// 第一个字节再此范围内，则开始判断第二个自己
        {
            int value2 = bytes[i + 1] & 0xFF;
            if

补充：移动开发 , Android ,