将指定的时间字符串转换成TimeStamp类型

第一种方式：

看TimeStamp类的源码：

public Timestamp(long time) {
        super((time/1000)*1000);
        nanos = (int)((time%1000) * 1000000);
        if (nanos < 0) {
            nanos = 1000000000 + nanos;
            super.setTime(((time/1000)-1)*1000);
        }
    }

可以看出要传入一个时间戳，就可以构造。

写了一个静态的方法：

public static Timestamp getAppointTimestamp1(String time){
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Timestamp timestamp = null;
        try {
            Date date = simpleDateFormat.parse(time);
            timestamp = new Timestamp(date.getTime());  //date.getTime() 就是时间戳
        } catch (ParseException e) {
            e.printStackTrace();
        }
        return timestamp;
    }

第二种方式：

TimeStamp类的源码：

public static Timestamp valueOf(String s) {
        final int YEAR_LENGTH = 4;
        final int MONTH_LENGTH = 2;
        final int DAY_LENGTH = 2;
        final int MAX_MONTH = 12;
        final int MAX_DAY = 31;
        String date_s;
        String time_s;
        String nanos_s;
        int year = 0;
        int month = 0;
        int day = 0;
        int hour;
        int minute;
        int second;
        int a_nanos = 0;
        int firstDash;
        int secondDash;
        int dividingSpace;
        int firstColon = 0;
        int secondColon = 0;
        int period = 0;
        String formatError = "Timestamp format must be yyyy-mm-dd hh:mm:ss[.fffffffff]";
        String zeros = "000000000";
        String delimiterDate = "-";
        String delimiterTime = ":";

        if (s == null) throw new java.lang.IllegalArgumentException("null string");

        // Split the string into date and time components
        s = s.trim();
        dividingSpace = s.indexOf(' ');
        if (dividingSpace > 0) {
            date_s = s.substring(0,dividingSpace);
            time_s = s.substring(dividingSpace+1);
        } else {
            throw new java.lang.IllegalArgumentException(formatError);
        }

        // Parse the date
        firstDash = date_s.indexOf('-');
        secondDash = date_s.indexOf('-', firstDash+1);

        // Parse the time
        if (time_s == null)
            throw new java.lang.IllegalArgumentException(formatError);
        firstColon = time_s.indexOf(':');
        secondColon = time_s.indexOf(':', firstColon+1);
        period = time_s.indexOf('.', secondColon+1);

        // Convert the date
        boolean parsedDate = false;
        if ((firstDash > 0) && (secondDash > 0) && (secondDash < date_s.length() - 1)) {
            String yyyy = date_s.substring(0, firstDash);
            String mm = date_s.substring(firstDash + 1, secondDash);
            String dd = date_s.substring(secondDash + 1);
            if (yyyy.length() == YEAR_LENGTH &&
                    (mm.length() >= 1 && mm.length() <= MONTH_LENGTH) &&
                    (dd.length() >= 1 && dd.length() <= DAY_LENGTH)) {
                 year = Integer.parseInt(yyyy);
                 month = Integer.parseInt(mm);
                 day = Integer.parseInt(dd);

                if ((month >= 1 && month <= MAX_MONTH) && (day >= 1 && day <= MAX_DAY)) {
                    parsedDate = true;
                }
            }
        }
        if (! parsedDate) {
            throw new java.lang.IllegalArgumentException(formatError);
        }

        // Convert the time; default missing nanos
        if ((firstColon > 0) & (secondColon > 0) &
            (secondColon < time_s.length()-1)) {
            hour = Integer.parseInt(time_s.substring(0, firstColon));
            minute =
                Integer.parseInt(time_s.substring(firstColon+1, secondColon));
            if ((period > 0) & (period < time_s.length()-1)) {
                second =
                    Integer.parseInt(time_s.substring(secondColon+1, period));
                nanos_s = time_s.substring(period+1);
                if (nanos_s.length() > 9)
                    throw new java.lang.IllegalArgumentException(formatError);
                if (!Character.isDigit(nanos_s.charAt(0)))
                    throw new java.lang.IllegalArgumentException(formatError);
                nanos_s = nanos_s + zeros.substring(0,9-nanos_s.length());
                a_nanos = Integer.parseInt(nanos_s);
            } else if (period > 0) {
                throw new java.lang.IllegalArgumentException(formatError);
            } else {
                second = Integer.parseInt(time_s.substring(secondColon+1));
            }
        } else {
            throw new java.lang.IllegalArgumentException(formatError);
        }

        return new Timestamp(year - 1900, month - 1, day, hour, minute, second, a_nanos);
    }

通过TimeStamp类的valueof(String time)静态方法直接传入字符串参数就可以了。

写了一个静态的方法：

public static Timestamp getAppointTimestamp2(String time){
        Timestamp timestamp = Timestamp.valueOf(time);
        return timestamp;
    }