static String readUTF()

in common/src/main/java/org/mvndaemon/mvnd/common/Message.java [237:301]
64 lines of code
18 McCabe index (conditional complexity)

    static String readUTF(DataInputStream input) throws IOException {
        byte[] byteBuf = BUF_TLS.get();
        int len = input.readInt();
        if (len == -1) {
            return null;
        }
        final char[] chars = new char[len];
        int i = 0, cnt = 0, charIdx = 0;
        while (charIdx < len) {
            if (i == cnt) {
                cnt = input.read(byteBuf, 0, Math.min(UTF_BUFS_BYTE_CNT, len - charIdx));
                if (cnt < 0) {
                    throw new EOFException();
                }
                i = 0;
            }
            final int a = byteBuf[i++] & 0xff;
            if (a < 0x80) {
                // low bit clear
                chars[charIdx++] = (char) a;
            } else if (a < 0xc0) {
                throw new UTFDataFormatException(INVALID_BYTE);
            } else if (a < 0xe0) {
                if (i == cnt) {
                    cnt = input.read(byteBuf, 0, Math.min(UTF_BUFS_BYTE_CNT, len - charIdx));
                    if (cnt < 0) {
                        throw new EOFException();
                    }
                    i = 0;
                }
                final int b = byteBuf[i++] & 0xff;
                if ((b & 0xc0) != 0x80) {
                    throw new UTFDataFormatException(INVALID_BYTE);
                }
                chars[charIdx++] = (char) ((a & 0x1f) << 6 | b & 0x3f);
            } else if (a < 0xf0) {
                if (i == cnt) {
                    cnt = input.read(byteBuf, 0, Math.min(UTF_BUFS_BYTE_CNT, len - charIdx));
                    if (cnt < 0) {
                        throw new EOFException();
                    }
                    i = 0;
                }
                final int b = byteBuf[i++] & 0xff;
                if ((b & 0xc0) != 0x80) {
                    throw new UTFDataFormatException(INVALID_BYTE);
                }
                if (i == cnt) {
                    cnt = input.read(byteBuf, 0, Math.min(UTF_BUFS_BYTE_CNT, len - charIdx));
                    if (cnt < 0) {
                        throw new EOFException();
                    }
                    i = 0;
                }
                final int c = byteBuf[i++] & 0xff;
                if ((c & 0xc0) != 0x80) {
                    throw new UTFDataFormatException(INVALID_BYTE);
                }
                chars[charIdx++] = (char) ((a & 0x0f) << 12 | (b & 0x3f) << 6 | c & 0x3f);
            } else {
                throw new UTFDataFormatException(INVALID_BYTE);
            }
        }
        return String.valueOf(chars);
    }