Error: unresolvable property or identifier: Base64 - mule

Question

I'm trying to call a REST service that is protected by basic authentication and I can't get this work. Basically, I need to setup the authorization header as
"Authorization: Basic [base64 encoded user name and password]".
My flow looks like this:
<flow name="testjsonFlow1" doc:name="testjsonFlow1">
<http:inbound-endpoint exchange-pattern="request-response" host="localhost" port="8081" path="testjson" doc:name="HTTP"/>
<set-property propertyName="Authorization" doc:name="Set Authentication Header" value="#["Basic " + Base64.encodeBase64String("username:password")]"/>
<http:outbound-endpoint exchange-pattern="request-response" host="<url>" port="80" path="Services/V1/testservices" method="POST" contentType="text/plain" doc:name="HTTP"/>
<echo-component doc:name="Echo"/>
</flow>
Invoking this flow results in the following error:
[Error: unresolvable property or identifier: Base64]
[Near : {... "Basic " + Base64.encodeBase64String("com ....}]
I see that the MuleStudio ships with commons-codec-1.3-osgi.jar while the Base64 API is not included and only comes with later version.
So my questions are:
Is this the right way to call a REST service that is protected with basic auth?
How can I resolve this issue?
How can I make the Mulestudio reference the commons-codec-1.9 jar instead of the commons-codec-1.3-osgi.jar?
Environment details: Windows 7 64 bit, Mule CE 3.4.
Any help is appreciated.
Update 1:
I made some updates to the script and it works now. Here is the updated script:
<flow name="testjsonFlow1" doc:name="testjsonFlow1">
<http:inbound-endpoint exchange-pattern="request-response" host="localhost" port="8081" path="testjson" doc:name="HTTP" />
<set-variable variableName="uName" doc:name="Variable" value="domain\user"/>
<set-variable variableName="pwd" doc:name="Variable" value="P#ssword"/>
<scripting:component doc:name="Groovy">
<scripting:script engine="Groovy">
<scripting:text><![CDATA[
def cred = message.getInvocationProperty("uName") + ":" + message.getInvocationProperty("pwd")
def credBytes = cred.bytes
def encodedCred = credBytes.encodeBase64().toString()
message.setProperty("credential",encodedCred)
return null;]]></scripting:text>
</scripting:script>
</scripting:component>
<set-property propertyName="Authorization" doc:name="Set Authentication Header" value="Basic #[header:OUTBOUND:credential]"/>
<logger level="INFO" doc:name="Logger"/>
<logger message="#[message.outboundProperties['Authorization']]" level="INFO" doc:name="Logger"/>
<http:outbound-endpoint exchange-pattern="request-response" host="myserver.com" port="80" path="Services/V1/service1/" method="POST" contentType="text/plain" doc:name="HTTP" />
</flow>

Answer 1

Answering your question to david in the comments above but hate pasting code into the comment editor.
You can add the user and pw to the endpoint and it'll base64 encode it like above.
<http:outbound-endpoint exchange-pattern="request-response"
host="foo.bar.com" port="80"
path="getFoo" method="GET"
user="username" password="password">
</http:outbound-endpoint>

Answer 2

<configuration>
<expression-language>
<import class="org.apache.commons.codec.binary.Base64" />
</expression-language>
</configuration>
or use the fully qualified class name in your expression.
But...
No, configure the username and password on the endpoint. See: http://www.mulesoft.org/documentation/display/current/Mule+Endpoint+URIs
Ditto.
Don't. Stick to the version provided by Mule. If you insist on using a most recent version, you'll need to package it with your application and use classloader override to ensure your application will use the packaged Commons Codec. See: http://www.mulesoft.org/documentation/display/current/Classloader+Control+in+Mule#ClassloaderControlinMule-Fine-GrainedClassloadingControl

Answer 3

Embedding user name and password on the http:outbound-endpoint didn't work as the password had a special character ('#') which was throwing a different exception. I made it work with a different approach and updated it in the question.