groovy script classpath

Question

I'm writing a script in Groovy and I would like someone to be able to execute it simply by running ./myscript.groovy. However, this script requires a 3rd party library (MySQL JDBC), and I don't know of any way to provide this to the script other than via a -classpath or -cp argument, e.g.

`./monitor-vouchers.groovy -cp /path/to/mysql-lib.jar`

For reasons I won't go into here, it's not actually possible to provide the JAR location to the script using the -classpath/-cp argument. Is there some way that I can load the JAR from within the script itself? I tried using @Grab

import groovy.sql.Sql


@Grab(group='mysql', module='mysql-connector-java', version='5.1.19')
def getConnection() {
    def dbUrl = 'jdbc:mysql://database1.c5vveqm7rqgx.eu-west-1.rds.amazonaws.com:3306/vouchers_prod'
    def dbUser = 'pucaroot'
    def dbPassword = 'password'
    def driverClass = "com.mysql.jdbc.Driver"

    return Sql.newInstance(dbUrl, dbUser, dbPassword, driverClass)
}

getConnection().class

But this causes the following error:

Caught: java.sql.SQLException: No suitable driver
java.sql.SQLException: No suitable driver
        at monitor-vouchers.getConnection(monitor-vouchers.groovy:13)
        at monitor-vouchers.run(monitor-vouchers.groovy:17)

Is there a way I can execute this script using just ./monitor-vouchers.groovy

Answer 1

You should be able to do:

import groovy.sql.Sql

@GrabConfig(systemClassLoader=true)
@Grab('mysql:mysql-connector-java:5.1.19')
def getConnection() {
    def dbUrl = 'jdbc:mysql://database1.c5vveqm7rqgx.eu-west-1.rds.amazonaws.com:3306/vouchers_prod'
    def dbUser = 'pucaroot'
    def dbPassword = 'bigsecret'
    def driverClass = "com.mysql.jdbc.Driver"

    return Sql.newInstance(dbUrl, dbUser, dbPassword, driverClass)
}

getConnection().class

Answer 2

Two more options:

1. Put the jar in ${user.home}/.groovy/lib

2. If the jar is in a known location, use this code to load it into the current class loader:

   this.class.classLoader.rootLoader.addURL( new URL() )