首页 > 安全资讯 >

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

12-09-04

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...

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

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

[html] 
boolean canBeGBK = true; 

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

[html] 
 //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

[html] 
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

[html]
/* 
 * 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 (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

                     

                       乱码

                      

相关文章
最新文章
热点推荐