How can I create a typed Tuple2 from Java / Spring?

I want to be able to create a Tuple2 from spring config where I explicitly declare the types of my parameters:

<bean class="scala.Tuple2">
      <constructor-arg index="0" value="Europe/London" type="java.util.TimeZone" />
      <constructor-arg index="1" value="America/New_York" type="java.util.TimeZone" />
</bean>

This does not work (I have the relevant property editors specified in my config file). At runtime I 开发者_JAVA百科get the error:

Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException:

Error creating bean with name 'scala.Tuple2#6504bc' defined in file [C:\Work\myproj\config\test\myproj.xml]: Unsatisfied dependency expressed through constructor argument with index 0 of type [java.lang.Object]:

Ambiguous constructor argument types - did you specify the correct bean references as constructor arguments?

The error goes away if I do not declare the explicit type - but then of course the Tuple2 in my program is just a (String, String) which is not what I want.

EDIT for those of you who did not know this, Spring uses PropertyEditors to create instances from Strings as follows:

public class TimeZoneEditor extends java.beans.PropertyEditorSupport {
    public void setAsText(String text) { setValue(TimeZone.getTimeZone(text)); }
    public String getAsText() { return ((TimeZone)getValue()).getID(); }
}

Now I simply declare in my config:

<bean id="customEditorConfigurer" 
       class="org.springframework.beans.factory.config.CustomEditorConfigurer">   
    <property name="customEditors"> 
        <map>
            <entry key="java.util.TimeZone">
                <bean class="my.cleve.rutil.TimeZoneEditor"/> 
            </entry>
        </map>
    </property> 
</bean>

And hey presto I can do things like:

<map key-type="java.util.TimeZone" value-type="java.lang.Integer">
    <entry key="Europe/London" value="4" />
</map>

Or alternatively Spring can figure out the generic type parameters from your setter methods. Except it doesn't seem to work in the case of my Tuple2!

You will need to create the TimeZone parameters explicitly using the static method getTimeZone() of class TimeZone:

<bean class="scala.Tuple2">
  <constructor-arg index="0">
    <bean class="java.util.TimeZone" factory-method="getTimeZone">
      <constructor-arg value="Europe/London"/>
    </bean>
  </constructor-arg>
  <constructor-arg index="1">
    <bean class="java.util.TimeZone" factory-method="getTimeZone">
      <constructor-arg value="America/New_York"/>
    </bean>
  </constructor-arg>
</bean>

It may be working for Map because spring has special support for it through the syntax you specified:

<map key-type="java.util.TimeZone" value-type="java.lang.Integer">

In this case, spring probably determines it should invoked the property editors based on the mismatch between the provided values of type String and the requested types TimeZone and Integer.