如何将两个String变量转换为date和timestamp列以插入数据库

Question

I need your help in getting the proper format to insert the date and time informaiton which is retrieved from two different string variables from the database and to insert them (date and time) into Date and Time column in an another table. The date is retrieved from the agreement date column which is:

String agreement_date = "";
agreement_date=rs.getString("agr_date"); //format DD-MON-YYYY ex. 22-May-2014

And the time is retrieved from:

String frm_time = rs.getString("FRM_TIME"); //format HH:MI ex.7:20

So now I need to combine both columns into one variable and to insert them in database column called transaction_dt_time and its type is dateTime(format dd/MM/YYYY HH:MI:SS AM/PM), So how can I do that?

Answer 1

You can concatenate these strings into datetime string and convert to date using SimpleDateFormat for example

SimpleDateFormat format = new SimpleDateFormat("dd-MMM-yyyy HH:mm");
Date dateToInsert = format.parse(concatenatedDate);

Answer 2

use a simpledateformat() for the time, is your time 24hours? how do we know if it's AM or PM?

SimpleDateFormat sdfTime = new SimpleDateFormat("HH:MI:SS"); //AM/PM?
String strTime = sdfTime.format(frm_time);

final_date = agreement_date.replaceAll("-","/");
String FinalDate = final_date + strTime;

Answer 3

I understand you are fetching the values in the resultset from a database. generally date and time are stored in database according to the datatype. Recommend to use a rs.getDate() and rs.getTime() to fetch these values instead of a String datatype.

Here is a sample code for your conversion

import java.sql.Timestamp;
import java.text.SimpleDateFormat;
import java.util.Date;

public class DateDemo  {

    public static void main(String[] args) {
        try{
            String date = "22-May-2015";
            String time = "7:20";
            String yourString = date+ " "+ time;
            SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MMM-yyyy HH:mm");
            Date parsedDate = dateFormat.parse(yourString);
            Timestamp timestamp = new java.sql.Timestamp(parsedDate.getTime());
            System.out.println(timestamp);
        }catch(Exception e){
            e.printStackTrace();
            //this generic but you can control another types of exception
            // look the origin of excption 
        }
    }
    }

Hope this helps!

Answer 4

您可以使用JPA 2.1及其AttributeConverter接口

Answer 5

java.time

The other answers use legacy date-time classes, now supplanted by the java.time framework built into Java 8 and later.

First, parse the date portion.

DateTimeFormatter dateFormatter = DateTimeFormatter.ofPattern( "mm-DD-yyyy" );
LocalDate localDate = LocalDate.parse( "22-May-2014" , dateFormatter );

Second, parse the time portion.

DateTimeFormatter dateFormatter = DateTimeFormatter.ofPattern( "h:m" );
LocalTime localTime = LocalTime.parse( "7:20" , dateFormatter );

Third, determine the time zone in which this value has meaning. Is this a Montréal time, a Paris time, or a Kolkata time?

ZoneId zoneId = ZoneId.of( "America/Montreal" );

Combine into a ZonedDateTime .

ZonedDateTime zdt = ZonedDateTime.of( localDate , localTime , zoneId );

You may be able to pass this ZonedDateTime to your database via the setObject method on a PreparedStatement with a JDBC 4.2 compliant driver. But if not, convert into the old java.sql.Timestamp type. That old class has a new method to facilitate conversion, which takes an Instant object. An Instant is a moment on the timeline in UTC with a resolution of nanoseconds. We can extract an Instant from our ZonedDateTime .

Instant instant = zdt.toInstant();
java.sql.Timestamp ts = java.sql.Timestamp.from( instant ); 

On your PreparedStatement , call setTimestamp .