How to map dates with hibernate – use joda-time

by | Sep 5, 2011 | Aggregated, Software |

This is always a question – how to map temporal data in our hibernate entities – whether to use java.util.Date, java.util.Calendar or simply long. The correct answer is: neither of these. Use joda-time – the de-facto Java datetime API. Using it throughout the whole project is a no-brainer, but how to use it with hibernate – you can’t use @Temporal. Hibernate supports custom types, so there’s a little project that solves the issue – joda-time – hibernate support.

The user guide is pretty clear:

@Column
@Type(type="org.joda.time.contrib.hibernate.PersistentDateTime")
private DateTime fromDate;

However, there’s one issue with that library – it uses static final fields from hibernate, which requires recompilation if the version of hibernate changes (see here). For that reason you may need to extend the PersistentDateTime class, override the 2 methods that use the static final TIMESTAMP field, and copy the exact same code from the superclass.

Using joda-time throughout the whole project will save tons of headaches. So I strongly suggest the above mechanism to use joda-time in your hibernate entities as well.

This is always a question – how to map temporal data in our hibernate entities – whether to use java.util.Date, java.util.Calendar or simply long. The correct answer is: neither of these. Use joda-time – the de-facto Java datetime API. Using it throughout the whole project is a no-brainer, but how to use it with hibernate – you can’t use @Temporal. Hibernate supports custom types, so there’s a little project that solves the issue – joda-time – hibernate support.

The user guide is pretty clear:

@Column
@Type(type="org.joda.time.contrib.hibernate.PersistentDateTime")
private DateTime fromDate;

However, there’s one issue with that library – it uses static final fields from hibernate, which requires recompilation if the version of hibernate changes (see here). For that reason you may need to extend the PersistentDateTime class, override the 2 methods that use the static final TIMESTAMP field, and copy the exact same code from the superclass.

Using joda-time throughout the whole project will save tons of headaches. So I strongly suggest the above mechanism to use joda-time in your hibernate entities as well.