Question

New to Java, and can’t figure out what I hope to be a simple thing.

I keep “sections” in an array:

//Section.java
public static final String[] TOP = {
    "Top News",
    "http://www.mysite.com/RSS/myfeed.csp",
    "top"
};

I’d like to do something like this:

Article a1 = new Article();
a1.["s_" + section[2]] = 1;  //should resolve to a1.s_top = 1;

But it won’t let me, as it doesn’t know what “section” is. (I’m sure seasoned Java people will cringe at this attempt… but my searches have come up empty on how to do this)

Clarification:

My article mysqlite table has fields for the “section” of the article:

s_top
s_sports
...etc

When doing my import from an XML file, I’d like to set that field to a 1 if it’s in that category. I could have switch statement:

//whatever the Java version of this is
switch(section[2]) {
    case "top": a1.s_top = 1; break;
    case "sports": a1.s_sports = 1; break;
    //...
}

But I thought it’d be a lot easier to just write it as a single line:

a1["s_"+section[2]] = 1;

Answer 1

In Java, it’s a pain to do what you want to do in the way that you’re trying to do it.

If you don’t want to use the switch/case statement, you could use reflection to pull up the member attribute you’re trying to set:

Class articleClass = a1.getClass();
Field field = articleClass.getField("s_top");
field.set(a1, 1); 

It’ll work, but it may be slow and it’s an atypical approach to this problem.

Alternately, you could store either a Map<String> or a Map<String,Boolean> inside of your Article class, and have a public function within Article called putSection(String section), and as you iterate, you would put the various section strings (or string/value mappings) into the map for each Article. So, instead of statically defining which sections may exist and giving each Article a yes or no, you’d allow the list of possible sections to be dynamic and based on your xml import.