Code Samples: Hibernate Transaction

So the problem is when we working on grails project with hibernate transaction to manage data, we do not know when actually transaction committed or not. But sometimes we have to wait until current transaction finally committed. Because unless transaction committed, this data will not available for other transactions. Below is a sample project showing how to notified or when actually current transaction committed. Its some wired way but its working.




THIS PROJECT FOR DEMONSTRATE HOW TO DO SOME ADDITIONAL WORK AFTER AN TRANSACTION COMMITED

1. First setup DataSource.groovy
2. Add *mavenRepo "https://oauth.googlecode.com/svn/code/maven"* in *repositories* to BuildConfig.groovy
3. Add below dependencies to *dependencies* in BuildConfig.groovy
    compile "org.springframework:spring-orm:$springVersion"
    runtime 'mysql:mysql-connector-java:5.1.29'
    runtime 'org.springframework:spring-test:4.0.5.RELEASE'
4. Add a controller named *HomeController.groovy*
5. Add a service named *HomeService.groovy*
6. Add a domain named *Home.groovy*

MOST IMPORTANT PARTS:
7. Add below groovy files
named *org.codehaus.groovy.grails.orm.hibernate.GrailsHibernateTransactionManager.groovy*
named *org.codehaus.groovy.grails.orm.hibernate.TransactionStatus.groovy*
named *org.codehaus.groovy.grails.orm.support.GrailsTransactionTemplate.groovy*
under *src/groovy*

8. You are done! See *HomeService.groovy* to see how you can use this feature in Grails project.



package org.codehaus.groovy.grails.orm.hibernate

import groovy.transform.CompileDynamic
import org.hibernate.FlushMode
import org.springframework.orm.hibernate4.HibernateTransactionManager
import org.springframework.transaction.TransactionDefinition
import org.springframework.transaction.support.DefaultTransactionStatus

class GrailsHibernateTransactionManager extends HibernateTransactionManager {
    @Override
    protected void doBegin(Object transaction, TransactionDefinition definition) {
        super.doBegin transaction, definition
        if (definition.isReadOnly()) {
            setFlushModeManual(transaction)
        }
    }

    @CompileDynamic
    protected void setFlushModeManual(transaction) {
        transaction.sessionHolder?.session?.flushMode = FlushMode.MANUAL
    }

    @Override
    protected DefaultTransactionStatus newTransactionStatus(TransactionDefinition definition, Object transaction, boolean newTransaction, boolean newSynchronization, boolean debug, Object suspendedResources) {
        return new TransactionStatus(super.newTransactionStatus(definition, transaction, newTransaction, newSynchronization, debug, suspendedResources))
    }

    @Override
    protected void doCommit(DefaultTransactionStatus status) {
        super.doCommit(status)
        status.triggerCommitHandlers()
    }
}


BELOW IS SAMPLE OUTPUT




package com.pritom

import grails.transaction.Transactional
import org.codehaus.groovy.grails.orm.hibernate.TransactionStatus

@Transactional
class HomeService {
    void saveEntity() {
        TransactionStatus.current.onCommit {
            println("YES!!! TRANSACTION COMMITTED SUCCESSFULLY!!!")
            println("HOME COUNT ${Home.count()}")
        }
        Home home = new Home()
        home.name = "House #${Home.count() + 1}"
        home.addreess = "Lane ${Home.count() + 1}, Dhaka"
        home.save()
    }
}



2019-02-08 11:33:55,048 [http-bio-8080-exec-1] DEBUG hibernate.SQL  - select count(*) as y0_ from home this_
Hibernate: select count(*) as y0_ from home this_
2019-02-08 11:33:55,050 [http-bio-8080-exec-1] DEBUG hibernate.SQL  - select count(*) as y0_ from home this_
Hibernate: select count(*) as y0_ from home this_
2019-02-08 11:33:55,053 [http-bio-8080-exec-1] DEBUG hibernate.SQL  - insert into home (version, addreess, name) values (?, ?, ?)
Hibernate: insert into home (version, addreess, name) values (?, ?, ?)
2019-02-08 11:33:55,054 [http-bio-8080-exec-1] TRACE sql.BasicBinder  - binding parameter [1] as [BIGINT] - [0]
2019-02-08 11:33:55,054 [http-bio-8080-exec-1] TRACE sql.BasicBinder  - binding parameter [2] as [VARCHAR] - [Lane 5, Dhaka]
2019-02-08 11:33:55,054 [http-bio-8080-exec-1] TRACE sql.BasicBinder  - binding parameter [3] as [VARCHAR] - [House #5]
YES!!! TRANSACTION COMMITTED SUCCESSFULLY!!!
2019-02-08 11:33:55,130 [http-bio-8080-exec-1] DEBUG hibernate.SQL  - select count(*) as y0_ from home this_
Hibernate: select count(*) as y0_ from home this_
HOME COUNT 5



You can use multiple TransactionStatus.current.onCommit, each will be called one after one.




You can download sample project from here




GitHub project link




Required JAR file to get this working (if dependecny failed)
Pages

Friday, February 8, 2019

GRAILS > FUNCTIONALITY AFTER TRANSACTION COMMITTED
