如何相互转换逗号分隔的字符串和List

public static void main(String[] args) {

//字符串转list
String strs = "a,b,c";
List<String> result = Arrays.asList(strs.split(","));
System.out.println(result);

//list转字符串分隔
List<String> list = new ArrayList<String>();
list.add("a");
list.add("b");
list.add("c");
String[] aaaa={"a","b","c"};
//来自谷歌com.google.common.base.Joiner guava
String str = Joiner.on(",").join(aaaa);

System.out.println(str);
}