Initialising an object with a string parameter

[chetan]

Hi,

I have a Constants interface with various Strings like home directory ,lib directory etc information placed in variables like

public interface ConstantsIF {
public static final String HOME="C:/";
}


one other class file works like this

DependentClass {
public DependentClass(String x) {
// do some thing with x here
}
}

if my x has to be a value like

ConstantsIF.HOME+"/config/config.xml";

then how do I pass that in the
<constructor-arg type="java.lang.String">
<value>??????????????</value>
</constructor-arg>


Can somebody help me with this please

Regards,
Chetan

[Mark Fisher]

Have a look at Spring's "FieldRetrievingFactoryBean" as described here:
http://static.springframework.org/sp...s.html#d0e2331

Or, if you are using Spring 2.0, you can use the new "util" namespace, like so:
<util:constant id="homeConstant" staticField="ConstantsIF.HOME"/>

[chetan]

Dear Mark,

I had a look at the first url mentioned,
I am able to get the value in the interface.but how do I concatenate this value with the one that I am supposed to pass.

if myield is the value obtained from the ConstantsIF using the
FieldRetrieving factory bean

then how do i achieve this concatenation effect

myField+"/config/config.xml"

such the spring application context understands the full path is of the form
C:/config/config.xml

Regards,
Chetan

[Mark Fisher]

Actually, for providing the "home" value as a prefix, I would consider using the PropertyPlaceholderConfigurer. That way the value for your home directory is stored in a properties file rather than hardcoded in the "ConstantsIF". You might consider trying something like this:

  <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="location" value="classpath:/example/constants.properties"/>
  </bean>
  
  <bean id="testBean" class="example.TestBean">
    <property name="filename" value="${home.dir}/rest/of/path"/>
  </bean>

Then in the constants.properties file, simply provide:

home.dir=/home

The TestBean instance's 'filename' property would then have a value of: "/home/rest/of/path"