Java Date/Time Cheat sheet

A concise cheat sheet for manipulating Date/Time objects in the most popular Java libraries and converting between Date/Time object types.

java.sql.Date

Converting between other DateTime types

LocalDate

For when we only care about the date and not the time.

    public java.time.LocalDate getLocalDate(final java.sql.Date date) {
        return date == null ? null : date.toLocalDate();
    }

    public java.sql.Date getSqlDate(final java.time.LocalDate localDate) {
        return localDate == null ? null : java.sql.Date.valueOf(localDate);
    }

LocalDateTime

When we need both the date and time values to convert appropriately.

public java.sql.Date getCurrentSqlDate() {
    return new java.sql.Date(getCurrentDate().getTime());
}

    @Override
    public LocalDateTime getLocalDateTimeAtStartOfDay(final java.sql.Date sqlDate) {
        return getLocalDate(sqlDate).atStartOfDay();
    }

    @Override
    public LocalDateTime getLocalDateTimeAtEndOfDay(final java.sql.Date sqlDate) {
        return getLocalDate(sqlDate).atTime(23, 59, 59, 59);
    }

    @Override
    public java.sql.Date getCurrentSqlDateMidnight() {
        // simple and not unduly inefficient way to truncate the time component
        return java.sql.Date.valueOf(getCurrentSqlDate().toString());
    }

 @Override
    public java.sql.Date convertToSqlDate(final String dateString) throws ParseException {
        if (StringUtils.isBlank(dateString)) {
            throw new IllegalArgumentException("invalid (blank) dateString");
        }
        final Date date = parseAgainstFormatArray(dateString, stringToDateFormats);
        return new java.sql.Date(date.getTime());
    }

    @Override
    public java.sql.Date convertToSqlDate(final Timestamp timestamp) {
        return new java.sql.Date(timestamp.getTime());
    }