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

You could write a little join-style utility method that works on java.util.Lists

public static String join(List list, String delim) {

    StringBuilder sb = new StringBuilder();

    String loopDelim = "";

    for(String s : list) {

        sb.append(loopDelim);
        sb.append(s);            

        loopDelim = delim;
    }

    return sb.toString();
}

Then use it like so:

    List list = new ArrayList();

    if( condition )        list.add("elementName");
    if( anotherCondition ) list.add("anotherElementName");

    join(list, ",");