package com.Big5ToUTF8;

import java.io.*;

public class Big5Tran {

private static final String tabFile ="bg-gb.tab";

private static byte[] data;

static{

try{

FileInputStream fis =new FileInputStream(tabFile);

int len =fis.available();

data =new byte[len];

fis.read(data);

fis.close();

}catch(Exception ex){

ex.printStackTrace();

System.exit(1);

}

}

/**

*取得BIG5汉字big在data中的偏移

*/

private static int indexOf(int big){

int high =(big>>>8)&0xff;

int low =big&0xff;

high -= 0xa1;

if(low<=0x7e) low -= 0x40;

else low -= (0xa1 -0x7e -1) +0x40;

return 2*(high*157+low);

}

/**

*将保存在bs数字中的big5编码的字符串数据转换成gb2312编码的数据

*注意:此方法将更改原先存储的数据

*@param bs 需要转换的以big5编码的字符串数据

*@return bs 经过转换的数据,保存在参数中的byte数组中

*/

public static byte[] translateBig5ToGb(byte[] bs){

int index =0;

while(index<bs.length){

int high =bs[index]&0xff;

if(high>=0xa1&&high<=0xfe){

index ++;

if(index>=bs.length) break;

int low =bs[index]&0xff;

if(low<0x40||low>0xfe) continue;

if(low>0x7e&&low<0xa1) continue;

int offset =indexOf((high<<8)|low);

bs[index-1] =data[offset];

bs[index ] =data[offset+1];

index++;

}

else index++;

}

return bs;

}

public static String translateBig5ToGb(String big){

String result =null;

try{

byte[] bs =big.getBytes("big5");

bs =translateBig5ToGb(bs);

result =new String(bs,"gb2312");

}catch(Exception e){

}

return result;

}

}