JAVA编码--Gbk-->Utf8

public static byte[] gbk2utf8(String chenese){
    char c[] = chenese.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);
//           System.out.println(word);
          
           StringBuffer sb = new StringBuffer();
           int len = 16 - word.length();
           //补零
           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");
          
//           System.out.println(sb.toString());
          
           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];
          
          }
          return fullByte;
   }