Java: convert List to a String

Question

JavaScript has Array.join()

js>[\"Bill\",\"Bob\",\"Steve\"].join(\" and \")
Bill and Bob and Steve

Does Java have anything

Answer 1

I wrote this one (I use it for beans and exploit toString, so don't write Collection):

public static String join(Collection col, String delim) {
    StringBuilder sb = new StringBuilder();
    Iterator iter = col.iterator();
    if (iter.hasNext())
        sb.append(iter.next().toString());
    while (iter.hasNext()) {
        sb.append(delim);
        sb.append(iter.next().toString());
    }
    return sb.toString();
}

but Collection isn't supported by JSP, so for TLD I wrote:

public static String join(List list, String delim) {
    int len = list.size();
    if (len == 0)
        return "";
    StringBuilder sb = new StringBuilder(list.get(0).toString());
    for (int i = 1; i < len; i++) {
        sb.append(delim);
        sb.append(list.get(i).toString());
    }
    return sb.toString();
}

and put to .tld file:

        join
        com.core.util.ReportUtil
        java.lang.String join(java.util.List, java.lang.String)
    

and use it in JSP files as:

<%@taglib prefix="funnyFmt" uri="tag:com.core.util,2013:funnyFmt"%>
${funnyFmt:join(books, ", ")}