DataIoUtils.java 文件源码

/**
 * Emulates {@link DataOutput#writeUTF(String)} without using it method.
 * @param output the target {@link DataOutput}
 * @param value the target value
 * @throws IOException if failed to write String into {@link DataOutput}
 */
public static void writeUTF(DataOutput output, String value) throws IOException {
    int size = computeUtfBodySize(value);
    if (size >>> Short.SIZE != 0) {
        throw new UTFDataFormatException("too long UTF string");
    }
    output.writeShort(size);
    for (int i = 0, n = value.length(); i < n; i++) {
        char c = value.charAt(i);
        if (c != CHAR_ZERO && c <= CHAR_MAX1) {
            output.write(c);
        } else if (c <= CHAR_MAX2) {
            output.write(MASK_HEAD2 | ((c >> 6) & MASK_BODY5));
            output.write(MASK_HEAD1 | (c & MASK_BODY6));
        } else {
            output.write(MASK_HEAD3 | ((c >> 12) & MASK_BODY4));
            output.write(MASK_HEAD1 | ((c >>  6) & MASK_BODY6));
            output.write(MASK_HEAD1 | (c & MASK_BODY6));
        }
    }
}