current community

your communities

more stack exchange communities

Stack Exchange
tour help
careers 2.0
Take the 2-minute tour ×
Stack Overflow is a question and answer site for professional and enthusiast programmers. It's 100% free, no registration required.
up vote 1 down vote favorite

I am re-learning Java after having an affair with PHP for some years, and I have a question about a convention used in PHP, and how I would accomplish a similar goal in Java...

PHP

function getReport( $options = array() ) {

}

in the above function you would be passing in an optional associative array of options that may look like this

Array(
    from => "20110325",
    to   => "20110413",
    subject_id => "2432",
    ...etc...
);

And if there is no argument passed, it processes fine with no options.

Below is my attempt to form the same function in java, being as it is Strongly typed (which is quite refreshing in some instances) I am having trouble building in the same flexibility. I've considered using a Dictionary but not sure how "best practice" that would be.

public TimeReport getTimeReport(Date from, Date to, int subjectId, int toDoItemId, int filterProjectId, int filterCompanyId) {

}

To call this with one/two/none options it gets pretty ugly with the arguments being...

getTimeReport(null,null,null,234,null,null);
share|improve this question
    
You can also pass in two separate lists, both having the same length. Or a single list with each element being an object having to, from, subject_id etc –  LazyCubicleMonkey Mar 14 '11 at 4:22

3 Answers 3

up vote 1 down vote accepted

Can you call the getTimeReport with another object used to represent the parameters needed to invoke the getTimeReport function?

Looks like your used to passing strings to functions when you may want to be passing an object.

share|improve this answer
up vote 1 down vote

This kind of flexibility is not built-in to Java, and the language is not very well suited to it in my opinion. You could check each input argument; if null, set it to a default value.

To be more general/didactic, it looks like you are trying to have a Factory of some sort (what class does the method getTimeReport() belong to?). Do you instead want to have the constructor of TimeReport handle these options? Or make different TimeReport constructors for different circumstances?

share|improve this answer
up vote 0 down vote

Usually you would introduce a class representing the configuration parameters for the report generation, like TimeReportSpecification or something.

You can then have static factory methods that give you instances of a TimeReportSpecification, like withToDoItem, so you get:

getTimeReport(TimeReportSpecification.withToDoItem(234));
share|improve this answer
    
I like where this is headed, but what if I want withToDoItem AND withSubjectId ? –  jondavidjohn Mar 14 '11 at 4:25
    
You can have a TimeReportSpecificationBuilder, so you do TimeReportSpecification.builder().withToDoItem(123).withSubjectId(456).build())‌​; See rwhansen.blogspot.com/2007/07/… for builder pattern information. –  sjr Mar 14 '11 at 4:30

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.