{"id":14842,"date":"2014-07-17T16:45:02","date_gmt":"2014-07-17T11:15:02","guid":{"rendered":"http:\/\/www.tothenew.com\/blog\/?p=14842"},"modified":"2014-07-18T10:58:18","modified_gmt":"2014-07-18T05:28:18","slug":"using-spring-events-in-grails","status":"publish","type":"post","link":"https:\/\/www.tothenew.com\/blog\/using-spring-events-in-grails\/","title":{"rendered":"Using Spring Events in Grails"},"content":{"rendered":"

Hi all,<\/p>\n

I have published a new blog post Using Spring Events in Grails.<\/p>\n

Spring Events are basically used to perform events asynchronously.<\/p>\n

In my use case I need to save hundreds of records in the database. So I use Spring Events to save records asynchronously.<\/p>\n

There is a plugin available in Grails for using Spring Events which save us from XML configurations and also provides a publishEvent method which can be called from a domain class, a controller or a service in the application.<\/p>\n

Plugin Link<\/a><\/p>\n

Spring Events work around two classes<\/p>\n

1. A class that extends ApplicationEvent
\n2. A class that implements ApplicationListener<\/p>\n

and publishEvent method is used to raise event that will be listen by a listener.<\/p>\n

Let’s start by taking an example.<\/p>\n

Author<\/span><\/p>\n

[java]
\npackage com.demo.domain<\/p>\n

class Author {<\/p>\n

String name
\n Integer age
\n}
\n[\/java]<\/p>\n

AuthorSaveEvent<\/span><\/p>\n

[java]
\npackage com.demo.events<\/p>\n

import org.springframework.context.ApplicationEvent<\/p>\n

class AuthorSaveEvent extends ApplicationEvent {<\/p>\n

AuthorSaveEvent(){
\n super([])
\n }<\/p>\n

}<\/p>\n

[\/java]<\/p>\n

EventListnerService<\/span><\/p>\n

[java]<\/p>\n

package com.demo.service<\/p>\n

import com.demo.domain.Author
\n import com.demo.events.AuthorSaveEvent
\n import grails.transaction.Transactional
\n import org.springframework.context.ApplicationListener<\/p>\n

@Transactional
\n class EventListnerService implements ApplicationListener {<\/p>\n

public void onApplicationEvent(AuthorSaveEvent event){
\n (1..10000).each {
\n new Author(name:"Madhav", age:23).save()
\n }
\n }
\n }<\/p>\n

[\/java]<\/p>\n

UtilController<\/span><\/p>\n

[java]<\/p>\n

package com.demo.controllers<\/p>\n

import com.demo.domain.Author
\n import com.demo.events.AuthorSaveEvent<\/p>\n

class UtilController {<\/p>\n

def withSpringEvent() {
\n AuthorSaveEvent authorSaveEvent = new AuthorSaveEvent()
\n publishEvent(authorSaveEvent)
\n render "Records saving has been Intailized"
\n }<\/p>\n

def withOutSpringEvent() {
\n (1..10000).each {
\n new Author(name: ‘Madhav’, age: 23).save()
\n }
\n render "All Records has been saved"
\n }
\n }<\/p>\n

[\/java]<\/p>\n

Let us talk about the flow of the application:<\/p>\n

1. When we hit the action of a controller then it will raise an event using publishEvent method.
\n2. Then the event will be listened by onApplicationEvent method of a class which is implementing the ApplicationListener interface.
\n3. Now the block of code in onApplicationEvent method will be executed on a separate thread.<\/p>\n

Comparsion of time taken for saving 10000 records<\/span><\/div>\n
<\/div>\n

1. withOutSpringEvent – it will take 6 minutes 20 seconds approx
\n2. withSpringEvent – it will take 18 seconds approx<\/p>\n

Hope this helps !! <\/p>\n

– Madhav Khanna
\nmadhav.khanna@intelligrape.com<\/p>\n","protected":false},"excerpt":{"rendered":"

Hi all, I have published a new blog post Using Spring Events in Grails. Spring Events are basically used to perform events asynchronously. In my use case I need to save hundreds of records in the database. So I use Spring Events to save records asynchronously. There is a plugin available in Grails for using […]<\/p>\n","protected":false},"author":96,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"iawp_total_views":17},"categories":[7],"tags":[408,4840,9,4841,1481],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/posts\/14842"}],"collection":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/users\/96"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/comments?post=14842"}],"version-history":[{"count":0,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/posts\/14842\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/media?parent=14842"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/categories?post=14842"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tothenew.com\/blog\/wp-json\/wp\/v2\/tags?post=14842"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}