關於LIst 轉String的三種方式

List<Integer> typeKey = pointImageMapper.selectPointByKey(rows.get(i).getPointKey());
Integer[] typeKeyS = new Integer[typeKey.size()];
for (int j = 0; j < typeKey.size(); j++) {
   typeKeyS[j] = typeKey.get(j);
}
//第一種比較累
String joins = StringUtils.join(typeKeyS, ",");
//第二種比較簡潔
Joiner.on(",").join(typeKey);
//第三種用流的形式，直接將integer轉換為String
typeKey.stream().map(String::valueOf).collect( Collectors.joining(","));