java 字符串转日期格式

    /**
     * 字符串转日期格式
     * */
    public static Date date(String date_str) {
        try {
            Calendar zcal = Calendar.getInstance();
            Timestamp timestampnow = new Timestamp(zcal.getTimeInMillis());
            SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
            ParsePosition pos = new ParsePosition(0);
            java.util.Date current = formatter.parse(date_str, pos);
            timestampnow = new Timestamp(current.getTime());
            return timestampnow;
        }
        catch (NullPointerException e) {
            return null;
        }
    }