字符串转换UTF-8编码

 　　/**
     * 转换UTF-8
     * @param string
     * @return
     */
    public static String toUtf8String(String string) {
        StringBuffer stringBuffer = new StringBuffer();
        for (int i = 0; i < string.length(); i++) {
            char c = string.charAt(i);
            if (c >= 0 && c <= 255) {
                stringBuffer.append(c);
            } else {
                byte[] b;
                try {
                    b = Character.toString(c).getBytes("utf-8");
                } catch (Exception ex) {
                    System.out.println(ex);
                    b = new byte[0];
                }
                for (int j = 0; j < b.length; j++) {
                    int k = b[j];
                    if (k < 0) k += 256;
                    stringBuffer.append("%" + Integer.toHexString(k).toUpperCase());
                }
            }
        }
        return stringBuffer.toString();
    }