public void fromByteArray(byte[] buffer, int offset, int byteCount) {/* Check the parameters. */if ((buffer == null) || (offset < 0) || (byteCount < 0)|| (offset + byteCount > buffer.length)) {return;}init();int index = 0;char track1Jis2Char = 0;char track1Char = 0;Track1State state = Track1State.START;int charCount = 0;/* Convert the byte to character. */for (index = 0; index < byteCount; index++) {track1Jis2Char = (char) (buffer[offset + index] & 0x7F);track1Char = TRACK1_CHAR_TABLE[buffer[offset + index] & 0x3F];mTrack1data += track1Char;switch (state) {case START:if (buffer[offset + index] == (byte) 0xFF) {state = Track1State.JIS2_DATA;} else {if (track1Char == START_SENTINEL) {state = Track1State.FORMAT_CODE;}}break;case JIS2_DATA:if (buffer[offset + index] == (byte) 0xFF) {state = Track1State.END;} else {mJis2Data += Character.isISOControl(track1Jis2Char) ? ' ': track1Jis2Char;}break;case FORMAT_CODE:state = Track1State.PRIMARY_ACCOUNT_NUMBER;break;case PRIMARY_ACCOUNT_NUMBER:if (track1Char == FIELD_SEPARATOR) {state = Track1State.NAME;} else {mPrimaryAccountNumber += track1Char;}break;case NAME:if (track1Char == FIELD_SEPARATOR) {charCount = 4;state = Track1State.EXPIRATION_DATE;} else {mName += track1Char;}break;case EXPIRATION_DATE:mExpirationDate += track1Char;charCount--;if (charCount <= 0) {charCount = 3;state = Track1State.SERVICE_CODE;}break;case SERVICE_CODE:mServiceCode += track1Char;charCount--;if (charCount <= 0) {state = Track1State.DISCRETIONARY_DATA;}break;case DISCRETIONARY_DATA:if (track1Char == END_SENTINEL) {state = Track1State.END;} else {mDiscretionaryData += track1Char;}break;default:break;}}}

2、第2磁道数据

 public void fromByteArray(byte[] buffer, int offset, int byteCount) {/* Check the parameters. */if ((buffer == null) || (offset < 0) || (byteCount < 0)|| (offset + byteCount > buffer.length)) {return;}init();int index = 0;char track2Char = 0;Track2State state = Track2State.START;int charCount = 0;/* Convert the byte to character. */for (index = 0; index < byteCount; index++) {track2Char = TRACK2_CHAR_TABLE[buffer[offset + index] & 0x0F];mTrack2data += track2Char;switch (state) {case START:if (track2Char == START_SENTINEL) {state = Track2State.PRIMARY_ACCOUNT_NUMBER;}break;case PRIMARY_ACCOUNT_NUMBER:if (track2Char == FIELD_SEPARATOR) {charCount = 4;state = Track2State.EXPIRATION_DATE;} else {mPrimaryAccountNumber += track2Char;}break;case EXPIRATION_DATE:mExpirationDate += track2Char;charCount--;if (charCount <= 0) {charCount = 3;state = Track2State.SERVICE_CODE;}break;case SERVICE_CODE:mServiceCode += track2Char;charCount--;if (charCount <= 0) {state = Track2State.DISCRETIONARY_DATA;}break;case DISCRETIONARY_DATA:if (track2Char == END_SENTINEL) {state = Track2State.END;} else {mDiscretionaryData += track2Char;}break;default:break;}}}

3、第3磁道数据

public void fromByteArray(byte[] buffer, int offset, int byteCount) {/* Check the parameters. */if ((buffer == null) || (offset < 0) || (byteCount < 0)|| (offset + byteCount > buffer.length)) {return;}init();int index = 0;char track3Char = 0;Track3State state = Track3State.START;int charCount = 0;/* Convert the byte to character. */for (index = 0; index < byteCount; index++) {track3Char = TRACK3_CHAR_TABLE[buffer[offset + index] & 0x0F];mTrack3data += track3Char;switch (state) {case START:if (track3Char == START_SENTINEL) {charCount = 2;state = Track3State.FORMAT_CODE;}break;case FORMAT_CODE:charCount--;if (charCount <= 0) {state = Track3State.PRIMARY_ACCOUNT_NUMBER;}break;case PRIMARY_ACCOUNT_NUMBER:if (track3Char == FIELD_SEPARATOR) {charCount = 3;state = Track3State.COUNTRY_CODE;} else {mPrimaryAccountNumber += track3Char;}break;case COUNTRY_CODE:mCountryCode += track3Char;charCount--;if (charCount <= 0) {charCount = 3;state = Track3State.CURRENCY_CODE;}break;case CURRENCY_CODE:mCurrencyCode += track3Char;charCount--;if (charCount <= 0) {state = Track3State.AMOUNT_INDEX;}break;case AMOUNT_INDEX:mAmountIndex += track3Char;charCount = 4;state = Track3State.PERIOD_AUTHORITY;break;case PERIOD_AUTHORITY:mPeriodAuthority += track3Char;charCount--;if (charCount <= 0) {charCount = 4;state = Track3State.PERIOD_BALANCE;}break;case PERIOD_BALANCE:mPeriodBalance += track3Char;charCount--;if (charCount <= 0) {charCount = 4;state = Track3State.PERIOD_BEGIN_DATE;}break;case PERIOD_BEGIN_DATE:mPeriodBeginDate += track3Char;charCount--;if (charCount <= 0) {charCount = 2;state = Track3State.PERIOD_LENGTH;}break;case PERIOD_LENGTH:mPeriodLength += track3Char;charCount--;if (charCount <= 0) {state = Track3State.PSW_INPUT_TIMES;}break;case PSW_INPUT_TIMES:mPswInputTimes += track3Char;charCount = 6;state = Track3State.P_AUTHORITY_CODE;break;case P_AUTHORITY_CODE:mPAuthorityCode += track3Char;charCount--;if (charCount <= 0) {state = Track3State.EXCHANGE_CONTROL_CODE;}break;case EXCHANGE_CONTROL_CODE:mExchangeControlCode += track3Char;charCount = 2;state = Track3State.PAN_TA_SR;break;case PAN_TA_SR:mPanTaSr += track3Char;charCount--;if (charCount <= 0) {charCount = 2;state = Track3State.SAN_1_TA_SR;}break;case SAN_1_TA_SR:mSan1TaSr += track3Char;charCount--;if (charCount <= 0) {charCount = 2;state = Track3State.SAN_2_TA_SR;}break;case SAN_2_TA_SR:mSan2TaSr += track3Char;charCount--;if (charCount <= 0) {charCount = 4;state = Track3State.EXPIRATION_DATE;}break;case EXPIRATION_DATE:mExpirationDate += track3Char;charCount--;if (charCount <= 0) {state = Track3State.SERIAL_NUMBER;}break;case SERIAL_NUMBER:mSerialNumber += track3Char;state = Track3State.CODE_NUMBER;break;case CODE_NUMBER:mCodeNumber += track3Char;state = Track3State.SAN_1;break;case SAN_1:if (track3Char == FIELD_SEPARATOR) {state = Track3State.SAN_2;} else {mSan1 += track3Char;}break;case SAN_2:if (track3Char == FIELD_SEPARATOR) {state = Track3State.PASS_MARK;} else {mSan2 += track3Char;}break;case PASS_MARK:mPassMark += track3Char;charCount = 6;state = Track3State.CRYPTOGRAPHIC_CHECK_DIGIT;break;case CRYPTOGRAPHIC_CHECK_DIGIT:mCryptographicCheckDigit += track3Char;charCount--;if (charCount <= 0) {state = Track3State.DISCRETIONARY_DATA;}break;case DISCRETIONARY_DATA:if (track3Char == END_SENTINEL) {state = Track3State.END;} else {mDiscretionaryData += track3Char;}break;default:break;}}}

PS：具体代码还是看这里-> 点我点我点我