Configuring the local MySql database connection to grails application - mysql

Question

I am a newbie to Grails, I have just started to create my first application just to make CRUD operations by storing the data to my local MySql database and I want to see the entered data in my machine. But I am unable to connect to database itself. Please help me where I am wrong.
My DataSource.groovy code is as shown below:
dataSource {
pooled = true
jmxExport = true
driverClassName = com.mysql.jdbc.Driver
dialect = org.hibernate.dialect.MySQL5InnoDBDialect
username = "test"
password = "test"
}
environments {
development {
dataSource {
dbCreate = "update"
url = "jdbc:mysql://localhost:3306/librarydb"
}
}
test {
dataSource {
dbCreate = "update"
url = "jdbc:mysql://localhost:3306/librarydb"
//url = "jdbc:h2:mem:testDb;MVCC=TRUE;LOCK_TIMEOUT=10000;DB_CLOSE_ON_EXIT=FALSE"
}
}
production {
dataSource {
dbCreate = "update"
url = "jdbc:mysql://localhost:3306/librarydb"
//url = "jdbc:h2:prodDb;MVCC=TRUE;LOCK_TIMEOUT=10000;DB_CLOSE_ON_EXIT=FALSE"
properties {
// See http://grails.org/doc/latest/guide/conf.html#dataSource for documentation
jmxEnabled = true
initialSize = 5
maxActive = 50
minIdle = 5
maxIdle = 25
maxWait = 10000
maxAge = 10 * 60000
timeBetweenEvictionRunsMillis = 5000
minEvictableIdleTimeMillis = 60000
validationQuery = "SELECT 1"
validationQueryTimeout = 3
validationInterval = 15000
testOnBorrow = true
testWhileIdle = true
testOnReturn = false
jdbcInterceptors = "ConnectionState"
defaultTransactionIsolation =
java.sql.Connection.TRANSACTION_READ_COMMITTED
}
}
}
}
And my BuildConfig.groovy file is configured as shown.
grails.servlet.version = "3.0" // Change depending on target container
compliance (2.5 or 3.0)
grails.project.class.dir = "target/classes"
grails.project.test.class.dir = "target/test-classes"
grails.project.test.reports.dir = "target/test-reports"
grails.project.work.dir = "target/work"
grails.project.target.level = 1.6
grails.project.source.level = 1.6
//grails.project.war.file = "target/${appName}-${appVersion}.war"
grails.project.fork = [
// configure settings for compilation JVM, note that if you alter the Groovy
version forked compilation is required
// compile: [maxMemory: 256, minMemory: 64, debug: false, maxPerm: 256,
daemon:true],
// configure settings for the test-app JVM, uses the daemon by default
test: [maxMemory: 768, minMemory: 64, debug: false, maxPerm: 256,
daemon:true],
// configure settings for the run-app JVM
run: [maxMemory: 768, minMemory: 64, debug: false, maxPerm: 256,
forkReserve:false],
// configure settings for the run-war JVM
war: [maxMemory: 768, minMemory: 64, debug: false, maxPerm: 256,
forkReserve:false],
// configure settings for the Console UI JVM
console: [maxMemory: 768, minMemory: 64, debug: false, maxPerm: 256]
]
grails.project.dependency.resolver = "maven" // or ivy
grails.project.dependency.resolution = {
// inherit Grails' default dependencies
inherits("global") {
// specify dependency exclusions here; for example, uncomment this to
disable ehcache:
// excludes 'ehcache'
}
log "error" // log level of Ivy resolver, either 'error', 'warn', 'info',
'debug' or 'verbose'
checksums true // Whether to verify checksums on resolve
legacyResolve false // whether to do a secondary resolve on plugin
installation, not advised and here for backwards compatibility
repositories {
inherits true // Whether to inherit repository definitions from plugins
grailsPlugins()
grailsHome()
mavenLocal()
grailsCentral()
mavenCentral()
// uncomment these (or add new ones) to enable remote dependency resolution from public Maven repositories
//mavenRepo "http://repository.codehaus.org"
//mavenRepo "http://download.java.net/maven/2/"
//mavenRepo "http://repository.jboss.com/maven2/"
}
dependencies {
// specify dependencies here under either 'build', 'compile', 'runtime', 'test' or 'provided' scopes e.g.
runtime 'mysql:mysql-connector-java:5.1.44'
// runtime 'org.postgresql:postgresql:9.3-1101-jdbc41'
test "org.grails:grails-datastore-test-support:1.0.2-grails-2.4"
}
plugins {
// plugins for the build system only
build ":tomcat:7.0.70" // or ":tomcat:8.0.22"
// plugins for the compile step
compile ":scaffolding:2.1.2"
compile ':cache:1.1.8'
// asset-pipeline 2.0+ requires Java 7, use version 1.9.x with Java 6
compile ":asset-pipeline:2.5.7"
// plugins needed at runtime but not for compilation
runtime ":hibernate4:4.3.10" // or ":hibernate:3.6.10.18"
runtime ":database-migration:1.4.0"
runtime ":jquery:1.11.1"
// Uncomment these to enable additional asset-pipeline capabilities
//compile ":sass-asset-pipeline:1.9.0"
//compile ":less-asset-pipeline:1.10.0"
//compile ":coffee-asset-pipeline:1.8.0"
//compile ":handlebars-asset-pipeline:1.3.0.3"
}
}
But I am getting the below error in my command prompt.
[localhost-startStop-1] ERROR pool.ConnectionPool - Unable to create initial connections of pool.
Message: class com.mysql.jdbc.Driver
Line | Method
->> 266 | run in java.util.concurrent.FutureTask
1149 | runWorker in java.util.concurrent.ThreadPoolExecutor
624 | run . . . in java.util.concurrent.ThreadPoolExecutor$Worker
748 | run in java.lang.Thread
Caused by ClassNotFoundException: class com.mysql.jdbc.Driver
->> 381 | findClass in java.net.URLClassLoader
424 | loadClass in java.lang.ClassLoader
348 | forName . in java.lang.Class
266 | run in java.util.concurrent.FutureTask
1149 | runWorker in java.util.concurrent.ThreadPoolExecutor
624 | run in java.util.concurrent.ThreadPoolExecutor$Worker
748 | run . . . in java.lang.Thread
Error |
2017-11-21 23:22:20,629 [localhost-startStop-1] ERROR
pool.ConnectionPool - Unable to create initial connections of pool.
Message: class com.mysql.jdbc.Driver
Line | Method
->>266 | run in java.util.concurrent.FutureTask
I am using Grails 2.5.6 version, and I have added the mysql-connector-java-5.1.44-bin.jar file in my lib folder of grails application and JAVA_HOME as well.Please help me to solve this and connect to my database to store the data. Thanks in advance.

Answer 1

Try grails clean
then grails refresh-dependencies ceck and make confirm the jar mysql:mysql-connector-java:5.1.29 is in your build path.
UPDATE :
Remove mysql dependency from BuildConfig.groovy if you have mysql-connector-java:5.x.x jar in the lib or vise-versa.
Multiple Jar file makes trouble.
Related post:
Unable to create initial connections of pool issues in Grails
java.lang.ClassNotFoundException:com.mysql.jdbc.Driver

Answer 2

The database needs to be reated first. Grails will try to connect to existing database, it will not be able to create a database for you.
Run these commands in the terminal, if you are using linux/unix, become a superuser and run the following:
CREATE DATABASE librarydb;
CREATE USER 'test'#'test' IDENTIFIED BY 'test';
GRANT ALL ON librarydb.* TO test#localhost;
if you have done all of that, please check username/password combo.
in terminal run this:
mysql -u test -p test and see if you can connect to the database.

Answer 3

it worked for me when I removed the jar file from the lib folder of my grails application and used the default mysql connection. i.e username="root" and password="root" in my datasource file. Thanks to #devbd for the answer.