commons.lang3.StringUtils

StringUtils.join(Object array[],String separator)

将数组以符号或其他字符串为间隔组成新的字符串

Object array[] 需要转换的数组。separator组成新串的间隔符号，如 “,” “|”

1 private static final String[] str = {"1","2","3","4"};
2 String str2 = StringUtils.join(str, "|");
3 
4 System.out.println(str2);

输出结果：1|2|3|4

List<String> list=new ArrayList<String>();
list.add("a");
list.add("b");
list.add("c");
String listjoin=StringUtils.join(list);
String listjoin2=StringUtils.join(list,",");
System.out.println(listjoin);
System.out.println(listjoin2);

StringBuffer sb=new StringBuffer();
sb.append("x,y,z,");
String arrjoin=StringUtils.join(sb.toString().split(","));
String arrjoin2=StringUtils.join(sb.toString().split(","),",");

System.out.println(arrjoin);
System.out.println(arrjoin2);

输出

[a, b, c]
a,b,c
xyz
x,y,z