This plugin works with 2.3.x of PlayFramework. It uses version 2.2.5 of HikariCP.

Note, it can be made to work with Play 2.2.x of the PlayFramework, but it requires changing the dependencies as the current build relies on the Play 2.3.x plugin.

HikariCP is supposed to be the fastest connection pool in Java land. But we did not start to use it because of speed, but because of its reliability. After suffering with connection leaks from BoneCP, we decide to implement our own database plugin to replace the default one. You can see a discussion about database exceptions caused by BoneCP (or misconfiguration of it). Also there are numerous other discussions about people having problems related to BoneCP.

Here is how HikariCP is working for us:

com.sandinh:play-hikaricp from maven center

There are just a few steps to properly configure the plugin. Just follow the steps bellow:

Add the following dependency to your project/build.sbt or project/Build.scala:

"com.sandinh" %% "play-hikaricp" % "1.7.1"

Add the following line to your conf/application.conf:

dbplugin=disabled

This will disable dbplugin and avoids that BoneCP creates useless connections (which in some cases can create database problems, like exhaust available connections).

Add the following line to your conf/play.plugins:

200:com.edulify.play.hikaricp.HikariCPPlugin

Due to the fact that the Play JPA plugin is assigned a priority of 400, please make sure that you assign com.edulify.play.hikaricp.HikariCPPlugin a priority less than that when using datasources looked up via JNDI. Otherwise, during application startup when JPA attempts to create the EntityManagerFactory your datasource will not have been bound to JNDI yet. Play documentation states that connection pools should use a 200 priority.

This is the preferred way to configure HikariCP because you have full access to all properties documented here and you can also have specific configuration to development, test and production modes. You can create a specific hikari properties file and configure it using db.default.hikaricp.file in you conf/application.conf file.

Per instance, if you have a conf/production.conf that is loaded by play in production mode, add the following line to this file:

 db.default.hikaricp.file="conf/hikaricp.prod.properties"

Of course, you need to create conf/hikaricp.dev.properties file.

Just create a conf/hikaricp.properties and the plugin will read it and create DataSource. This mode has preference over using ordinary play way because you have fine grained access to Hikari configuration.

The least recommended way. Configure database properties as stated in the Play docs. The table bellow shows how Play configurations are mapped to HikariCP:

•                                          | `db.default.partitionSize`     | * Unused/NA
  

maximumPoolSize (partitionSize * maxPoolSize) | db.default.maxPoolSize | minimumPoolSize (partitionSize * minPoolSize) | db.default.minPoolSize | maxLifetime | db.default.maxConnectionAge | idleTimeout | db.default.idleMaxAge
db.default.idleMaxAgeInMinutes
db.default.idleMaxAgeInSeconds | connectionTimeout | db.default.connectionTimeout
db.default.connectionTimeoutInMs | leakDetectionThreshold | db.default.closeConnectionWatchTimeout
db.default.closeConnectionWatchTimeoutInMs | connectionInitSql | db.default.initSQL | - connectionTestQuery | db.default.connectionTestStatement | - autoCommit | db.default.defaultAutoCommit | transactionIsolation | db.default.defaultTransactionIsolation | - readOnly | db.default.defaultReadOnly | catalog | db.default.defaultCatalog | - registerMbeans | db.default.statisticsEnabled |

Thanks to community contribution, the plugin supports to bind a DataSource to a JNDI context. After properly configuring the plugin (as described above), just add the following configuration in you application.conf:

 db.default.jndiName="DefaultDataSource"

When using Heroku, you need to read database url string from an environment variable called DATABASE_URL. Plain java Properties does not offer a way to reference these environment variables in a properties file, then we use Commons Configuration to read the hikaricp.properties file or the one configured by db.default.hikaricp.file.

Here is an example:

jdbcUrl=${env:DATABASE_URL}
driverClassName=org.postgresql.Driver

connectionTestQuery=SELECT 1
registerMbeans=true

# 15 minutes
maxLifetime=900000
# 5 minutes
idleTimeout=300000

maximumPoolSize=20
minimumIdle=5

The code here is highly inspired by the following plugins:

1. swaldman/c3p0-play
2. autma/play-hikaricp-plugin

We decide to do our own because both plugins above looks unmaintained.

There are also two other alternatives using c3p0:

1. hadashi/play2-c3p0-plugin
2. Furyu/play-c3p0-plugin

Copyright 2015 sandinh.com

Copyright 2014 Edulify.com

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.