字符串与二进制字符流之间相互转换,JAVA_二进制字符串流

private static String[] PREFIX_POOL = {"0", "00", "000", "0000", "00000", "000000", "0000000", "00000000",
            "000000000", "0000000000", "00000000000", "000000000000",
            "0000000000000", "00000000000000", "000000000000000"
    };
 
    /**
     * 字符串转换成二进制流
     *
     * @param str 字符串
     * @return 二进制流
     */
    private static String toBinary(String str) {
        if (null == str || str.trim().length() == 0) {
            return null;
        }
 
        char[] strChar = str.toCharArray();
        StringBuilder result = new StringBuilder(strChar.length << 4);
        for (int i = 0; i < strChar.length; i++) {
            // 二进制ASCII码
            String s = Integer.toBinaryString(strChar[i]);
            // 补0
            if (s.length() < 16) {
                s = PREFIX_POOL[15 - s.length()].concat(s);
            }
 
            result.append(s);
        }
 
        return result.toString();
    }
 
    /**
     * 二进制流转换成字符串
     *
     * @param binaryString 二进制流
     * @return 字符串
     */
    private static String toString(String binaryString) {
        if (null == binaryString || binaryString.trim().length() == 0) {
            return null;
        }
 
        int len = binaryString.length();
        StringBuilder sb = new StringBuilder(len >> 4);
        int step = 16;
        for (int i = 0; i < len; i += step) {
            // 将ascll码强转成字符
            sb.append((char) (int) Integer.parseInt(binaryString.substring(i, i + step), 2));
        }
 
        return sb.toString();
    }