List<String> list =new ArrayList();
list.add(“ab”);
list.add("cd");
String str = Joiner.on(",").join(list);
最终结果：str=ab,cd
添加gradle依赖：compile group:‘com.google.guava‘,name:"guava",version:20.0
List<String> list =new ArrayList();
list.add(“ab”);
list.add("cd");
String str = Joiner.on(",").join(list);
最终结果：str=ab,cd
添加gradle依赖：compile group:‘com.google.guava‘,name:"guava",version:20.0
原文：https://www.cnblogs.com/sam-cheng/p/8422677.html