public static String readUTF8()

in hyracks/hyracks-util/src/main/java/org/apache/hyracks/util/string/UTF8StringUtil.java [451:532]
72 lines of code
23 McCabe index (conditional complexity)

    public static String readUTF8(DataInput in, UTF8StringReader reader) throws IOException {
        int utflen = VarLenIntEncoderDecoder.decode(in);
        byte[] bytearr;
        char[] chararr;

        if (reader == null) {
            bytearr = new byte[utflen * 2];
            chararr = new char[utflen * 2];
        } else {
            if (reader.bytearr == null || reader.bytearr.length < utflen) {
                reader.bytearr = new byte[utflen * 2];
                reader.chararr = new char[utflen * 2];
            }
            bytearr = reader.bytearr;
            chararr = reader.chararr;
        }

        int c, char2, char3;
        int count = 0;
        int chararr_count = 0;

        in.readFully(bytearr, 0, utflen);

        while (count < utflen) {
            c = bytearr[count] & 0xff;
            if (c > 127) {
                break;
            }
            count++;
            chararr[chararr_count++] = (char) c;
        }

        while (count < utflen) {
            c = bytearr[count] & 0xff;
            switch (c >> 4) {
                case 0:
                case 1:
                case 2:
                case 3:
                case 4:
                case 5:
                case 6:
                case 7:
                    /* 0xxxxxxx*/
                    count++;
                    chararr[chararr_count++] = (char) c;
                    break;
                case 12:
                case 13:
                    /* 110x xxxx   10xx xxxx*/
                    count += 2;
                    if (count > utflen) {
                        throw new UTFDataFormatException("malformed input: partial character at end");
                    }
                    char2 = bytearr[count - 1];
                    if ((char2 & 0xC0) != 0x80) {
                        throw new UTFDataFormatException("malformed input around byte " + count);
                    }
                    chararr[chararr_count++] = (char) (((c & 0x1F) << 6) | (char2 & 0x3F));
                    break;
                case 14:
                    /* 1110 xxxx  10xx xxxx  10xx xxxx */
                    count += 3;
                    if (count > utflen) {
                        throw new UTFDataFormatException("malformed input: partial character at end");
                    }
                    char2 = bytearr[count - 2];
                    char3 = bytearr[count - 1];
                    if (((char2 & 0xC0) != 0x80) || ((char3 & 0xC0) != 0x80)) {
                        throw new UTFDataFormatException("malformed input around byte " + (count - 1));
                    }
                    chararr[chararr_count++] = (char) (((c & 0x0F) << 12) | ((char2 & 0x3F) << 6)
                            | ((char3 & 0x3F) << 0));
                    break;
                default:
                    /* 10xx xxxx,  1111 xxxx */
                    throw new UTFDataFormatException("malformed input around byte " + count);
            }
        }
        // The number of chars produced may be less than utflen
        return new String(chararr, 0, chararr_count);
    }