java GBK字符转换成为UTF-8编码字符

import java.util.HashMap;
import java.util.Map;
/**
 * 创建日期: 2014-04-18 10:36:25
 * 作者: 黄飞
 * mail：[e-mail] [e-mail]
 * ©版权归作者所有
 * */
public class ConverFromGBKToUTF8 {
public static void main(String[] args) {
try {
ConverFromGBKToUTF8 convert = new ConverFromGBKToUTF8();
String fullStr = convert.gbk2utf8("半角变拳脚,quanjiao "); 

System.out.println( fullStr  ) ;
} catch (Exception e) {
e.printStackTrace(); 
}
}

private StringUtil chinese(String chinese){
StringUtil util = new StringUtil();
char[]chars = chinese.toCharArray() ;
int index = 0 ;
StringBuffer buffer = new StringBuffer();
for(char c : chars){
String temp = String.valueOf(c) ;
if(temp.getBytes().length == 1){
util.map.put( index , temp ) ;
}else{
buffer.append( temp );
}
index++;
}
util.chinese = buffer.toString() ;
return util ;
}

public String gbk2utf8(String chenese) {
StringUtil strUtil = chinese( chenese ) ;
char c[] = strUtil.chinese.toCharArray( ) ;
byte[] fullByte = new byte[3 * c.length];
for (int i = 0; i < c.length; i++) {
int m = (int) c[i];
String word = Integer.toBinaryString(m);

StringBuffer sb = new StringBuffer();
int len = 16 - word.length();
for (int j = 0; j < len; j++) {
sb.append("0");
}
sb.append(word);
sb.insert(0, "1110");
sb.insert(8, "10");
sb.insert(16, "10");

String s1 = sb.substring(0, 8);
String s2 = sb.substring(8, 16);
String s3 = sb.substring(16);

byte b0 = Integer.valueOf(s1, 2).byteValue();
byte b1 = Integer.valueOf(s2, 2).byteValue();
byte b2 = Integer.valueOf(s3, 2).byteValue();
byte[] bf = new byte[3];
bf[0] = b0;
fullByte[i * 3] = bf[0];
bf[1] = b1;
fullByte[i * 3 + 1] = bf[1];
bf[2] = b2;
fullByte[i * 3 + 2] = bf[2];
}
String reutrnStr = null ;
try {
reutrnStr = new String(fullByte, "UTF-8");
} catch (Exception e) {
} 
StringBuffer returnBuffer = new StringBuffer(  reutrnStr );
for(Map.Entry<Integer, String> entry : strUtil.map.entrySet()){
returnBuffer.insert(entry.getKey() , entry.getValue() ) ;
}

return returnBuffer.toString() ;
}
}

class StringUtil{
public String chinese ; 

public Map<Integer , String> map = new HashMap<Integer, String>();
}