Java8 Date/Time Support For FreeMarker

This is a tiny Java library that adds basic support for the new Java 8 date/time api to FreeMarker. Its not a perfect solution as we cannot add built-ins to FreeMarker from external code. Hopefully FreeMarker will add native support in the future, but there are no implementation being worked on at the moment (http://freemarker.org/contribute.html).

The library has basic formatting support for all classes in the java.time api introduced in Java 8, using the new java.time.format.DateTimeFormatter. We have also introduced som comparison methods.

Take a look at our feature test spec too see how it all works : https://github.com/amedia/freemarker-java-8/blob/master/src/test/resources/no/api/freemarker/java8/time/

Requirements

Java 8 or higher. Tested on Freemarker 2.3.23, but should at least work fine for all 2.3.x versions. Please file an issue if you have problems with other versions.

Installation

freemarker-java-8 is deployed to the Maven Central Repository. You can include the package in your Maven POM like this :

<dependency>
    <groupId>no.api.freemarker</groupId>
    <artifactId>freemarker-java8</artifactId>
    <version>1.1.5</version>
</dependency>

Make sure to replace the version with the current version found in the pom.

Usage

You need to configure FreeMarker with our package by adding the Java8ObjectWrapper.

this.configuration = new Configuration(); // Or get the configuration from your framework like DropWizard or Spring Boot.
this.configuration.setObjectWrapper(new Java8ObjectWrapper(Configuration.VERSION_2_3_23));

Usage within Spring

Within a Spring project you can add this configuration class to your project:

import no.api.freemarker.java8.Java8ObjectWrapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.freemarker.FreeMarkerAutoConfiguration;
import org.springframework.context.annotation.Configuration;

import javax.annotation.PostConstruct;

@Configuration
public class FreemarkerConfig extends FreeMarkerAutoConfiguration.FreeMarkerWebConfiguration {

    @Autowired
    private freemarker.template.Configuration configuration;

    @PostConstruct
    public void postConstruct() {
        configuration.setObjectWrapper(
                new Java8ObjectWrapper(freemarker.template.Configuration.getVersion())); // VERSION_2_3_26
    }

}

java.time support

We had to cheat a little bit to add format methods to our date.time classes. This is why you will see that our syntax differs from the default FreeMarker built-ins.

All format methods uses the java.time.format.DateTimeFormatter for formatting.

Table 1. java.time template methods

java.time class	methods	comment	example
Clock	`format()`	This is a simple implementation where format just prints the toString() value of the object.	`${myclock.format()}`
Duration	`nano(), seconds()`	Gives access to the Duration values	`${myduration.seconds}, ${myduration.nano}`
Instant	`format()`	This is a simple implementation where format just prints the toString() value of the object.	`${myinstant.format()}`
LocalDate	`format(), format(pattern)`	Allows you to print a LocalDate on a default pattern, by providing a custom pattern or a builtin format style.	`${mylocaldate.format()}`, `${mylocaldate.format('yyyy MM dd')}` or `${mylocaldate.format('FULL_DATE')}`
LocalDateTime	`format(), format(pattern)`	Allows you to print a LocalDateTime on a default pattern, by providing a custom pattern or a builtin format style.	`${mylocaldatetime.format()}`, `${mylocaldatetime.format('yyyy-MM-dd HH : mm : ss')}` or `${mylocaldatetime.format('MEDIUM_DATETIME')}`
LocalTime	`format(), format(pattern)`	Allows you to print a LocalTime on a default pattern, by providing a custom pattern or a builtin format style.	`${mylocaltime.format()}`, `${mylocaltime.format('HH : mm : ss')}` or `${mylocaltime.format('SHORT_TIME')}`
MonthDay	`format(), format(pattern)`	Allows you to print a MonthDay on a default pattern or by providing a custom pattern.	`${mymonthday.format()}` or `${mymonthday.format('MM dd')}`
OffsetDateTime	`format(), format(pattern)`	Allows you to print a OffsetDateTime on a default pattern, by providing a custom pattern or a builtin format style.	`${myoffsetdatetime.format()}`, `${myoffsetdatetime.format('yyyy MM dd HH mm ss')}` or `${myoffsetdatetime.format('FULL_DATETIME')}`
OffsetTime	`format(), format(pattern)`	Allows you to print a OffsetTime on a default pattern, by providing a custom pattern or a builtin format style.	`${myoffsettime.format()}`, `${myoffsettime.format('HH mm ss')}` or `${myoffsettime.format('MEDIUM_TIME')}`
Period	`days(), months(), years()`	Gives access to the values of the Period object.	`${myperiod.days}, ${myperiod.months}, ${myperiod.years}`
Year	`format(), format(pattern)`	Allows you to print a Year on a default pattern or by providing a custom pattern.	`${myyear.format()}` or `${myyear.format('yyyy')}`
YearMonth	`format(), format(pattern)`	Allows you to print a YearMonth on a default pattern or by providing a custom pattern.	`${myyear.format()}` or `${myyear.format('yyyy MM')}`
ZonedDateTime	`format(), format(pattern), format(pattern, zoneId)`	Allows you to print a YearMonth on a default pattern/timezone or by providing a custom pattern.	`${myzoneddatetime.format()}` or `${myzoneddatetime.format('yyyy-MM-dd Z')}` or `${myzoneddatetime.format('yyyy-MM-dd Z', 'Asia/Seoul')}`
ZoneId	`format(), format(textStyle), format(textstyle, locale)`	Prints the ZoneId display name. You can override the textstyle with one of these values [FULL, FULL_STANDALONE, SHORT, SHORT_STANDALONE, NARROW and NARROW_STANDALONE]. You can also override the locale, but Java only seems to have locale support for a few languages.	`${myzoneid.format()}` or `${myzoneid.format('short')}` or `${myzoneid.format('short', 'no-NO')}`
ZoneOffset	`format(), format(textStyle)`	Prints the ZoneOffset display name. You can override the textstyle with one of these values [FULL, FULL_STANDALONE, SHORT, SHORT_STANDALONE, NARROW and NARROW_STANDALONE]. You can also override the locale, but Java only seems to have locale support for a few languages.	${myzoneoffset.format()}` or `${myzoneoffset.format('short')}` or `${myzoneoffset.format('short', 'no-NO')}

Table 2. java.time comparison methods

java.time class	methods	comment	example
LocalDate	`isEqual(<LocalDate object>), isAfter(<LocalDate object>), isBefore(<LocalDate object>)`	Can compare two LocalDate objects for equality.	`${localDate.isEqual(anotherlocalDate)} or ${localDate.isAfter(anotherlocalDate)} or ${localDate.isBefore(anotherlocalDate)}`
LocalDateTime	`isEqual(<LocalDateTime object>), isAfter(<LocalDateTime object>), isBefore(<LocalDateTime object>)`	Can compare two LocalDateTime objects for equality.	`${localDateTime.isEqual(anotherlocalDateTime)} or ${localDateTime.isAfter(anotherlocalDateTime)} or ${localDateTime.isBefore(anotherlocalDateTime)}`
LocalTime	`isEqual(<LocalTime object>), isAfter(<LocalTime object>), isBefore(<LocalTime object>)`	Can compare two LocalTime objects for equality.	`${localTime.isEqual(anotherlocalTime)} or ${localTime.isAfter(anotherlocalTime)} or ${localTime.isBefore(anotherlocalTime)}`

michaelkrog / freemarker-java-8 Goto Github PK

freemarker-java-8's Introduction

Java8 Date/Time Support For FreeMarker

Requirements

Installation

Usage

Usage within Spring

java.time support

freemarker-java-8's People

Contributors

Watchers

Recommend Projects

React

Vue.js

Typescript

TensorFlow

Django

Laravel

D3

Recommend Topics

javascript

web

server

Machine learning

Visualization

Game

Recommend Org

Facebook

Microsoft

Google

Alibaba

D3

Tencent