private String join(List elements) {
if (elements == null || elements.size() == 0) {
return "";
} else if (elements.size() == 1) {
return elements.get(0).toString();
} else if (elements.size() == 2) {
return elements.get(0) + " and " + elements.get(1);
}
StringBuffer sb = new StringBuffer();
for (Iterator it = elements.iterator(); it.hasNext();) {
String next = (String) it.next();
if (sb.length() > 0) {
if (it.hasNext()) {
sb.append(", ");
} else {
sb.append(", and ");
}
}
sb.append(next);
}
return sb.toString();
}

import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

public class Xxx {
private String join(List elements) {
if (elements == null || elements.size() == 0) {
return "";
} else if (elements.size() == 1) {
return elements.get(0).toString();
} else if (elements.size() == 2) {
return elements.get(0) + " and " + elements.get(1);
}
StringBuffer sb = new StringBuffer();
for (Iterator it = elements.iterator(); it.hasNext();) {
String next = (String) it.next();
if (sb.length() > 0) {
if (it.hasNext()) {
sb.append(", ");
} else {
sb.append(", and ");
}
}
sb.append(next);
}
return sb.toString();
}

private void test() {
System.out.println(join(Arrays.asList(new String[]{"Apple", "Banana", "Carrot"})));
System.out.println(join(Arrays.asList(new String[]{"One", "Two"})));
System.out.println(join(Arrays.asList(new String[]{"Lonely"})));
}

public static void main(String[] args) {
new Xxx().test();
}
}

System.out.println(join(fruit));

import java.util.List;
import java.util.Arrays;

public class Solution388 {
public static void main(String[] args) {

List<String> fruit = Arrays.asList(new String[]{"Apple", "Banana", "Carrot"});

System.out.println(join(fruit));
}

static String join(List<String> list)
{
if (list.size() == 0) return "";
if (list.size() == 1) return list.get(0);
if (list.size() == 2) return ((new StringBuilder(list.get(0))).append(" and ").append(list.get(1))).toString();

StringBuilder sb = new StringBuilder(128);
for (String item : list.subList(0, list.size() - 1)) sb.append(item).append(", ");
return (sb.append("and ").append(list.get(list.size() - 1))).toString();
}
}