conditional statement in .properties file

Question

Is there a way we can have conditional statement inside a .properties file?

like:

if(condition1)
    xyz = abc
else if(condition2)
    xyz = efg

Answer 1

No, it's not possible. The file format is freely available: http://docs.oracle.com/javase/6/docs/api/java/util/Properties.html#load%28java.io.Reader%29.

Do this in Java code:

if (condition1) {
    return properties.getProperty("xyz.1");
}
else if (condition2) {
    return properties.getProperty("xyz.2");
}

Answer 2

No There is no such conditional statement in properties file, May be you would write a wrapper over Properties to encapsulate your logic

Example:

class MyProperties extends Properties {


    /**
     * 
     * 
     * 
     * @param key
     * @param conditionalMap
     * @return
     */
    public String getProperty(String key, List<Decision> decisionList) {
        if (decisionList == null) {
            return getProperty(key);
        }
        Long value = Long.parseLong(getProperty(key));
        for (Decision decision : decisionList) {
            if (Condition.EQUALS == decision.getCondition() && decision.getValue().equals(value)) {
                return getProperty(decision.getTargetKey());
            }
        }
        return super.getProperty(key);
    }
}

and

enum Condition {
    EQUALS, GREATER, LESSER

}

and

class Decision {
    Condition condition;
    String targetKey;
    Long value;
    //accessor

    public Condition getCondition() {
        return condition;
    }

    public void setCondition(Condition condition) {
        this.condition = condition;
    }

    public String getTargetKey() {
        return targetKey;
    }

    public void setTargetKey(String targetKey) {
        this.targetKey = targetKey;
    }

}

so now for example if you want to read the properties file, get category of age, if it is greater than 0 and less than 10 read kid

so may be you could pass the list of such conditions,

note: This design can go under much improvement (not good design), it is just to illustrate how to wrap properties and add stuff that OP wants

Answer 3

If your problem is different properties for different environments (e.g. devl, test, perf, prod), the common solution is a different version of the properties file for each environment. Communicate environment info to your app and look for a file with the correct name appended to the file name.

Something like this for Spring:

Environment-specific configuration for a Spring-based web application?

Answer 4

As @Jigar said, there is no conditional logic in a properties file. But you could have two lines in there, e.g. something like:

xyz.condition1 = abs
xyz.condition2 = efg

and, in your code to access the property, append the proper condition to the key.

Answer 5

this is the way:

xyz[condition1]=abs
xyz[condition2]=efg