转换列表<String>为分隔字符串

Question

可能重复：
Java: convert List<String> to a join()d string

有了这个：

List<String> elementNames = Arrays.asList("h1", "h2", "h3", "h4", "h5", "h6"); 

什么是优雅的方式与自定义分隔符来获得字符串，像这样：

"h1,h2,h3,h4,h5,h6" 

Answer 1

如果你不介意使用的Apache提供的StringUtils的图书馆，你可以这样做：

// Output is "a,b,c" 
StringUtils.join(["a", "b", "c"], ','); 

https://commons.apache.org/proper/commons-lang/javadocs/api-2.6/org/apache/commons/lang/StringUtils.html

Answer 2

StringBuilder sb = new StringBuilder(); 

for(String s: elementnames) { 
    sb.append(s).append(','); 
} 

sb.deleteCharAt(sb.length()-1); //delete last comma 

String newString = sb.toString(); 

更新：启动Java 8中，您可以使用获得同样的结果：

List<String> elementNames = Arrays.asList("1", "2", "3"); 

    StringJoiner joiner = new StringJoiner(",", "", ""); 
    elementNames.forEach(joiner::add); 

    System.out.println(joiner.toString());