JDK8 String转List 、List 及List转String

String  auctionBlockIds="45,46,47";

一、String 转List<String>

List<String> auctionBlockId= Arrays.asList(auctionBlockIds.split(",")).stream().map(block -> (block.trim())).collect(Collectors.toList());
或：Arrays.asList(StringUtils.split("1,2,2,3,4,5,6,6", ","));

 二、List<String> 转  String 

String auctionBlockIds=String.join(",",auctionBlockId);
三、 String 转List<Integer>

List<Integer> auctionBlockId= Arrays.stream(auctionBlockIds.split(",")).map(s -> Integer.valueOf(s.trim())).collect(Collectors.toList());


四、List<Integer> 转 String 
String requisitionLineIds=list.stream().map(requisitionLine->String.valueOf(requisitionLine.getRequisitionLineId())).collect(Collectors.joining(","));