Decoding Binary Signage: Converting UTF‑8 Binary to Chinese Characters in Java

A public restroom sign displays the slogan "向前一小步，文明一大步" in Chinese, English, Japanese, and Korean, followed by a long string of 0s and 1s. The author, noticing the binary pattern, suspects it encodes the Chinese text using UTF‑8.

UTF‑8 is a variable‑length Unicode encoding where a single‑byte character starts with a leading 0, two‑byte characters start with 110, three‑byte characters with 1110, and four‑byte characters with 11110. All continuation bytes begin with 10. By examining the binary string, the first three bits are 1110, indicating a three‑byte UTF‑8 character (24 bits).

The author extracts the first 24 bits, removes the leading marker bits (the red‑highlighted bits in the original image), and obtains the payload 0101 010000 010001. Converting this binary to hexadecimal yields 0x5411, which corresponds to the Unicode code point for the Chinese character "向".

To decode the entire binary message automatically, the author provides a Java method that assembles the binary string, splits it into bytes, converts each byte to an integer, builds a byte array, and constructs a new String from the array. The code is:

private static void toChinese() {
    String bits = "11100101100100001001000111100101100010011000110"
                + "1111001001011100010000000111001011011000010001111111001"
                + "10101011011010010100100000111001101001011010000111111001"
                + "10100110001000111011100100101110001000000011100101101001"
                + "0010100111111001101010110110100101";
    int length = bits.length();
    byte[] bytes = new byte[length >> 3];
    for (int i = 0; i < length; i += 8) {
        String byteString = bits.substring(i, i + 8);
        bytes[i >> 3] = (byte) Integer.parseInt(byteString, 2);
    }
    System.out.println("转换之后的结果：" + new String(bytes));
}

Running the program prints the decoded Chinese text, confirming that the binary sequence indeed represents the character "向" and demonstrating a practical method for converting UTF‑8 binary data to readable characters.