Is it possible to one variable points to other in java properties file?

Question

I have a lot of rows/entry in my properties file. Rows are grouped in categories to keep file easier to maintain. I have two key which have the same value. I don't want to remove one because it makes my file harder to maintain.

#category1
var1=foo
....
#category2
var2=foo

Is there any way to make var1 points to var2? I think about sth like that:

    #category1
    var1=->var2 #point to var2
    ....
    #category2
    var2=foo

Possible duplicate: http://stackoverflow.com/questions/872272/how-to-reference-another-property-in-java-util-properties — Ray Stojonic, Sep 21 '13 at 22:51
@superEb Support values-as-keys in my code is difficult becouse I use org.springframework.context.support.ReloadableResourceBundleMessageSource which uses properties file. — Mariusz, Sep 21 '13 at 23:03
You could, but you'd have to interpret and expand he values yourself — MadProgrammer, Sep 21 '13 at 23:12

score 0 · Accepted Answer · answered Sep 21 '13 at 23:26

java.util.Properties implements the Map interface so you can do everything that this interface offers with it. To allow value to represent a reference to an other key you could wrap the code for getting the value in such a ways that it check whether the value is actually key and then return the value that is mapped by that key.

so you could implement something like this:

String value1 = p.getProperty("var1");
while(p.containsKey(value1)) {
    value1 = p.getProperty(value1);
}

better: add a prefix - $ for example - to value to identify a reference, only if present then resolve:

String value1 = p.getProperty("var1");
while(value1.startsWith("$")) {
    value1 = p.getProperty(value1.substring(1));
}

A good way for wrapping the retrieve-code is by extending the Properties class and override the method getProperty.

For org.springframework.context.support.ReloadableResourceBundleMessageSource you could extend it, override which ever methods you want and configure spring to inject your version of the class.

I wanted a quick way to facilitate my task. Your way is not quick becasue of the need to extend ReloadableResourceBundleMessageSource. I do not like to shoot out of a cannon to fly. But your answer is correct so I accepted it. Thanks. — Mariusz, Sep 23 '13 at 22:04

Is it possible to one variable points to other in java properties file?

1 Answers1