One, string and Date (java.util.Date) interchange
1.1 String-> Date
String datestr = "//::";
Date date = new Date ();
Note format must match the format of date string
dateformat sdf = new SimpleDateFormat ("Yyyy/mm/dd HH:mm:ss");
try {
date = Sdf.parse (DATESTR);
System.out.println (Date.tostring ());
} catch (Exception e) {
e.printstacktrace ();
}
String datestr = "2010/05/04 12:34:23";
Date date = new Date ();
Note format must match the format of date string
dateformat sdf = new SimpleDateFormat ("Yyyy/mm/dd HH:mm:ss");
try {
date = Sdf.parse (DATESTR);
System.out.println (Date.tostring ());
} catch (Exception e) {
e.printstacktrace ();
1.2 Date-> String
Date to string conversion, you can set any conversion format
String datestr = "";
Date date = new Date ();
Format can be arbitrary
dateformat sdf = new SimpleDateFormat ("Yyyy/mm/dd HH:mm:ss");
DateFormat SDF = new SimpleDateFormat ("Yyyy-mm-dd hh/mm/ss");
try {
datestr = Sdf.format (date);
System.out.println (DATESTR);
Datestr = Sdf.format (date);
System.out.println (DATESTR);
} catch (Exception e) {
e.printstacktrace ();
}
String datestr = "";
Date date = new Date ();
Format can be arbitrary
dateformat sdf = new SimpleDateFormat ("Yyyy/mm/dd HH:mm:ss");
DateFormat sdf2 = new SimpleDateFormat ("Yyyy-mm-dd hh/mm/ss");
try {
datestr = Sdf.format (date);
System.out.println (DATESTR);
Datestr = Sdf2.format (date);
System.out.println (DATESTR);
} catch (Exception e) {
e.printstacktrace ();
Two, string and timestamp mutual turn
2.1 String->timestamp
Using the timestamp valueof () method
Timestamp ts = new Timestamp (System.currenttimemillis ());
String tsstr = "--::";
try {
ts = timestamp.valueof (TSSTR);
SYSTEM.OUT.PRINTLN (TS);
} catch (Exception e) {
e.printstacktrace ();
}
Timestamp ts = new Timestamp (System.currenttimemillis ());
String tsstr = "2011-05-09 11:49:45";
try {
ts = timestamp.valueof (TSSTR);
SYSTEM.OUT.PRINTLN (TS);
} catch (Exception e) {
e.printstacktrace ();
Note: String must be of type such as: Yyyy-mm-dd hh:mm:ss[.f ...] in this format, brackets indicate optional, otherwise the error is!!!
If the string is in another format, consider parsing the string again, and then reorganizing ~ ~
2.2 Timestamp-> String
Use Timestamp's ToString () method or borrow DateFormat
Timestamp ts = new Timestamp (System.currenttimemillis ());
String tsstr = "";
DateFormat SDF = new SimpleDateFormat ("Yyyy/mm/dd HH:mm:ss");
try {
//method one
tsstr = Sdf.format (ts);
System.out.println (TSSTR);
Method two
tsstr = ts.tostring ();
System.out.println (TSSTR);
} catch (Exception e) {
e.printstacktrace ();
}
Timestamp ts = new Timestamp (System.currenttimemillis ());
String tsstr = "";
DateFormat SDF = new SimpleDateFormat ("Yyyy/mm/dd HH:mm:ss");
try {
//method one
tsstr = Sdf.format (ts);
System.out.println (TSSTR);
Method two
tsstr = ts.tostring ();
System.out.println (TSSTR);
} catch (Exception e) {
e.printstacktrace ();
It is easy to see that the advantage of method one is that it is flexible to set the form of a string.
Iii. Date (java.util.Date) and timestamp interchange
Statement: Check API, date and Timesta are parent-child relationships
3.1 Timestamp-> Date
Timestamp ts = new Timestamp (System.currenttimemillis ());
Date date = new Date ();
try {
date = ts;
SYSTEM.OUT.PRINTLN (date);
catch (Exception e) {
e.printstacktrace ();
}
Timestamp ts = new Timestamp (System.currenttimemillis ());
Date date = new Date ();
try {
date = ts;
SYSTEM.OUT.PRINTLN (date);
catch (Exception e) {
e.printstacktrace ();
}
Very simple, but at the moment the date object points to an entity that is a timestamp, that is, date has a method of the date class, but the executing entity of the overridden method is in timestamp.
3.2 Date-> Timestamp
The parent class cannot be directly converted to subclasses, with the help of the middle string~~~~
Java.sql.Date only store date data does not store time data
//will lose time Data
preparedstatement.setdate (1, New Java.sql.Date (Date.gettime ()));
This can be done with
Preparedstatement.settimestamp (1, New Java.sql.Timestamp (New Java.util.Date (). GetTime ()));
Want to get complete data, including date and time, you can do so
java.util.Date d = resultset.gettimestamp (1);
This is a more appropriate process to avoid some potential timestamp problems
java.util.Date d = new Java.util.Date (Resultset.gettimestamp (1). GetTime ());
Make up your own words, such words:
When storing to the database, you can receive the Java.util.Date type and then use the GetTime () method to get a long value representing that date object, and then construct a timestamp object into the database with this long value.
When you take it from a stored database, you can get timestamp to use his gettime () method to get a long value and then construct a Java.util.Date object with this long value so that you can manipulate the date object. It's better to say new Simpletimeformat ("Yyyyy-mm-dd HH:mm:ss"). Format () and so on