Using MySQL with Grails 2.0 - Finding an External .jar Connector

Question

I am using Grails 2.0 and I am unable to get the code to recognize an external library. In particular, the MySQL driver.

Basically the problem occurs when I try to change my DataSource from HSQLDB to MySql. I downloaded the jar (5.0.8) and placed it in the (project) / lib directory. I checked that the com.mysql.jdbc.Driver.class file is in the .jar.

Every time I try to run the application, I get an error message:

Thrown ClassNotFoundException: com.mysql.jdbc.Driver

Any help is greatly appreciated.

dataSource { pooled = true //driverClassName = "org.h2.Driver" //username = "sa" //password = "" driverClassName = "com.mysql.jdbc.Driver" username = "bob" password = "password" } hibernate { cache.use_second_level_cache = true cache.use_query_cache = true cache.region.factory_class = 'net.sf.ehcache.hibernate.EhCacheRegionFactory' } // environment specific settings environments { development { dataSource { //dbCreate = "create-drop" // one of 'create', 'create-drop', 'update', 'validate', '' //url = "jdbc:h2:mem:devDb;MVCC=TRUE" dbCreate = "update" // one of 'create', 'create-drop', 'update', 'validate', '' url = "jdbc:mysql://localhost:3306/tekevent" } } test { dataSource { dbCreate = "create-drop" url = "jdbc:h2:mem:testDb;MVCC=TRUE" } } production { dataSource { dbCreate = "update" url = "jdbc:h2:prodDb;MVCC=TRUE" pooled = true properties { maxActive = -1 minEvictableIdleTimeMillis=1800000 timeBetweenEvictionRunsMillis=1800000 numTestsPerEvictionRun=3 testOnBorrow=true testWhileIdle=true testOnReturn=true validationQuery="SELECT 1" } } } } 

Answer 1

Delete the jar and use the dependency declaration in BuildConfig.groovy . Instead of having multiple copies of many cans, it is much better to download them each time and cache them in the Ivy cache and reference them from there.

BuildConfig.groovy already has an example for MySQL; just uncomment it and update if necessary. Also make sure the mavenCentral() repository is uncommented:

 repositories { ... mavenCentral() } dependencies { ... runtime 'mysql:mysql-connector-java:5.1.16' }