(1)将逗号分隔的字符串转换为集合:
方法1:利用JDK的Arrays类
String str = "a,b,c";
List<String> result = Arrays.asList(str.split(","));
方法2: 利用Guava的Splitter
String str = "a, b, c";
List<String> result = Splitter.on(",").trimResults().splitToList(str);
方法 3: 利用Apache Commons的StringUtils (只是用了split)
String str = "a,b,c";
List<String> result = Arrays.asList(StringUtils.split(str,","));
(2)将List转换为逗号分隔符:
方法1: 利用Guava的Joiner
List<String> list = new ArrayList<String>();
list.add("a");
list.add("b");
list.add("c");
String str = Joiner.on(",").join(list);
方法2: 利用Apache Commons的StringUtils
List<String> list = new ArrayList<String>();
list.add("a");
list.add("b");
list.add("c");
String str = StringUtils.join(list.toArray(), ",");