// 将逗号分隔的字符串转换为List
String str = "a,b,c";
// 1.使用JDK,逗号分隔的字符串-->数组-->list
List<String> result = Arrays.asList(str.split(","));
// 2.使用Apache Commons的StringUtils
List<String> result1 = Arrays.asList(StringUtils.split(str, ","));
// 3.通过遍历
String[] strings = str.split(",");
List<String> result2 = new ArrayList<String>();
for (String string : strings) {
    result2.add(string);
}