Justin Dag » spring http://justindag.com Fri, 26 Mar 2010 16:29:35 +0000 http://wordpress.org/?v=2.8.5 en hourly 1 Grails, Constructor Injection, and Spring Bean Builders http://justindag.com/2008/07/grails-constructor-injection-and-spring-bean-builders/ http://justindag.com/2008/07/grails-constructor-injection-and-spring-bean-builders/#comments Sat, 19 Jul 2008 01:40:58 +0000 admin http://justindag.com/?p=4 Had a run-in with Grails and trying to wire up some custom beans using Grails’s Spring Bean Builder DSL mechanism. I was wiring up an instance of the Apache HttpClient object, which can be constructed with HttpClientParams and/or HttpConnectionManager. Now the Grails BB syntax expects the first argument to be the type you’re wiring, followed by the parameters to pass into the constructor. Something like this:
httpClient(org.apache.commons.httpclient.HttpClient, defaultGlobalHttpConnectionManager)

Where httpClient is the bean name/id, org.apache.commons.httpclient.HttpClient is the type we’re wiring, and defaultGlobalHttpConnectionManager is some custom implementation of the HttpConnectionManager.

When using this Bean Builder syntax, Grails gets consfused about the argument ordering and is unable to create its Grails Application Context. I also tried the following which didn’t work either.
httpClient(org.apache.commons.httpclient.HttpClient, null,
defaultGlobalHttpConnectionManager)

I don’t know if you can explicitly set the arguments the same way you can in the standard XML wiring approach. My solution was then to use the tried and true method.

<bean id="defaultGlobalHttpConnectionManager"
class="com.site.commons.http.GlobalHttpConnectionManager"
destroy-method="shutDown" lazy-init="default" autowire="default"
dependency-check="default">
<property name="soTimeout">
<value>20000</value>
</property>
<property name="connectionTimeout">
<value>20000</value >
</property>
</bean>

<bean id="httpClient"
class="org.apache.commons.httpclient.HttpClient" lazy-init="default"
autowire="default"
dependency-check="default">
<constructor-arg ref="defaultGlobalHttpConnectionManager" />
</bean>

Resources:
http://grails.org/doc/1.0.x/
http://hc.apache.org/httpclient-3.x/apidocs/index.html

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