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
http://yajin167.info/2011/07/01/integrated-zxing-scan-barcode.html
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
private static final String GBK = "GB2312";
2、在boolean canBeUTF8 = true;下面添加
boolean canBeGBK = true;
2、在 int value = bytes[i] & 0xFF;下面开始添加
//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
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，
我在csdn上也上传了一份我编译的core.jar,直接可用，地址是：http://download.csdn.net/detail/abowu/4547532
最后我把完整的StringUtils.java代码放上来，可以对比着看
/* * 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 * * 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.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 (value2 > 0xA0 && value2 <= 0xF7) { canBeGBK = true; }} } // UTF-8 stuff if (value >= 0x80 && value <= 0xBF) { if (utf8BytesLeft > 0) { utf8BytesLeft--; } } else { if (utf8BytesLeft > 0) { canBeUTF8 = false; } if (value >= 0xC0 && value <= 0xFD) { sawUTF8Start = true; int valueCopy = value; while ((valueCopy & 0x40) != 0) { utf8BytesLeft++; valueCopy <<= 1; } } } // ISO-8859-1 stuff if ((value == 0xC2 || value == 0xC3) && i < length - 1) { // This is really a poor hack. The slightly more exotic characters people might want to put in // a QR Code, by which I mean the Latin-1 supplement characters (e.g. u-umlaut) have encodings // that start with 0xC2 followed by [0xA0,0xBF], or start with 0xC3 followed by [0x80,0xBF]. int nextValue = bytes[i + 1] & 0xFF; if (nextValue <= 0xBF && ((value == 0xC2 && nextValue >= 0xA0) || (value == 0xC3 && nextValue >= 0x80))) { sawLatin1Supplement = true; } } if (value >= 0x7F && value <= 0x9F) { canBeISO88591 = false; } // Shift_JIS stuff if (value >= 0xA1 && value <= 0xDF) { // count the number of characters that might be a Shift_JIS single-byte Katakana character if (!lastWasPossibleDoubleByteStart) { maybeSingleByteKatakanaCount++; } } if (!lastWasPossibleDoubleByteStart && ((value >= 0xF0 && value <= 0xFF) || value == 0x80 || value == 0xA0)) { canBeShiftJIS = false; } if (((value >= 0x81 && value <= 0x9F) || (value >= 0xE0 && value <= 0xEF))) { // These start double-byte characters in Shift_JIS. Let's see if it's followed by a valid // second byte. if (lastWasPossibleDoubleByteStart) { // If we just checked this and the last byte for being a valid double-byte // char, don't check starting on this byte. If this and the last byte // formed a valid pair, then this shouldn't be checked to see if it starts // a double byte pair of course. lastWasPossibleDoubleByteStart = false; } else { // ... otherwise do check to see if this plus the next byte form a valid // double byte pair encoding a character. lastWasPossibleDoubleByteStart = true; if (i >= bytes.length - 1) { canBeShiftJIS = false; } else { int nextValue = bytes[i + 1] & 0xFF; if (nextValue < 0x40 || nextValue > 0xFC) { canBeShiftJIS = false; } else { maybeDoubleByteCount++; } // There is some conflicting information out there about which bytes can follow which in // double-byte Shift_JIS characters. The rule above seems to be the one that matches practice. } } } else { lastWasPossibleDoubleByteStart = false; } } if (utf8BytesLeft > 0) { canBeUTF8 = false; } // Easy -- if assuming Shift_JIS and no evidence it can't be, done if (canBeShiftJIS && ASSUME_SHIFT_JIS) { return SHIFT_JIS; } if (canBeUTF8 && sawUTF8Start) { return UTF8; } // Distinguishing Shift_JIS and ISO-8859-1 can be a little tough. The crude heuristic is: // - If we saw // - at least 3 bytes that starts a double-byte value (bytes that are rare in ISO-8859-1), or // - over 5% of bytes could be single-byte Katakana (also rare in ISO-8859-1), // - and, saw no sequences that are invalid in Shift_JIS, then we conclude Shift_JIS if (canBeShiftJIS && (maybeDoubleByteCount >= 3 || 20 * maybeSingleByteKatakanaCount > length)) { return SHIFT_JIS; }if(canBeGBK){return GBK;} // Otherwise, we default to ISO-8859-1 unless we know it can't be if (!sawLatin1Supplement && canBeISO88591) {return ISO88591;// return GB2312; } // Otherwise, we take a wild guess with platform encoding return PLATFORM_DEFAULT_ENCODING; }}
再上一个效果对比图吧
识别的二维码图片是
解决前后的对比图
乱码
