groovy.lang.MissingMethodException: No signature of method

[Schumann Ye]

Dear Gurus,

I tried to use groovy file to customize the back-end language setting with the 
following steps:
1.      Change the "GlobalDecorator" Screen of the file 
framework\common\widget\commonscreens.xml by adding the following highlighted 
underlined codes:

    <!-- Global decorator for General Screens/Pages -->
    <screen name="GlobalDecorator">
        <section>
            <widgets>
                <include-screen name="GlobalActions" />
                <section>
                    <actions>
                        <set field="layoutSettings.commonHeaderImageLinkUrl" 
from-field="layoutSettings.commonHeaderImageLinkUrl" default-value="main" 
global="true" />
                        <set field="iconsLocation" 
from-field="layoutSettings.VT_ICONS_LOC[0]" 
default-value="/images/icons/famfamfam" global="true" />
                        <set field="headerTemplateLocation" 
from-field="layoutSettings.VT_HDR_TMPLT_LOC[0]" />
                        <set field="footerTemplateLocation" 
from-field="layoutSettings.VT_FTR_TMPLT_LOC[0]" />
                        <set field="appbarTemplateLocation" 
from-field="layoutSettings.VT_NAV_TMPLT_LOC[0]" />
                        <set field="appbarOpenTemplateLocation" 
from-field="layoutSettings.VT_NAV_OPEN_TMPLT[0]" />
                        <set field="appbarCloseTemplateLocation" 
from-field="layoutSettings.VT_NAV_CLOSE_TMPLT[0]" />
                        <set field="messagesTemplateLocation" 
from-field="layoutSettings.VT_MSG_TMPLT_LOC[0]" />
                        <set field="layoutSettings.suppressTab" 
value="ofbizsetup"/><!-- diseable ofbiz setup by default -->
                        <script 
location="component://common/groovyScripts/SetLocale.groovy"/>
                    </actions>
                    <widgets />
                </section>
                           ......

2.      Then I added the SetLocale.groovy file in the above location as follows:

import org.apache.ofbiz.base.util.UtilHttp

setLocale(request,"zh_CN")

3.      After a reboot, I got the following error message and could not figure 
out why.

(Error running script at location 
[component://common/groovyScripts/SetLocale.groovy]: 
groovy.lang.MissingMethodException: No signature of method: 
SetLocale.setLocale() is applicable for argument types: 
(org.apache.catalina.connector.RequestFacade, java.lang.String) values: 
[org.apache.catalina.connector.RequestFacade@2a5d73ab, zh_CN])))

Pls help me! Thanks!

Best Regards

Schumann