What's the best way to build a string of delimited items in Java?

Question

While working in a Java app, I recently needed to assemble a comma-delimited list of values to pass to another web service without knowing how many elements there would be i

Answer 1

Why don't you do in Java the same thing you are doing in ruby, that is creating the delimiter separated string only after you've added all the pieces to the array?

ArrayList parms = new ArrayList();
if (someCondition) parms.add("someString");
if (anotherCondition) parms.add("someOtherString");
// ...
String sep = ""; StringBuffer b = new StringBuffer();
for (String p: parms) {
    b.append(sep);
    b.append(p);
    sep = "yourDelimiter";
}

You may want to move that for loop in a separate helper method, and also use StringBuilder instead of StringBuffer...

Edit: fixed the order of appends.