Java中实现String字符串用逗号隔开
作者:playboy-jordan
这篇文章主要介绍了Java中实现String字符串用逗号隔开,具有很好的参考价值,希望对大家有所帮助。如有错误或未考虑完全的地方,望不吝赐教
String字符串用逗号隔开
在Java中,有两个方法可以用逗号把String分开
一个是
public String[] split(String regex) { return split(regex, 0); }
另一个是
public String[] split(String regex, int limit) { /* fastpath if the regex is a (1)one-char String and this character is not one of the RegEx's meta characters ".$|()[{^?*+\\", or (2)two-char String and the first char is the backslash and the second is not the ascii digit or ascii letter. */ char ch = 0; if (((regex.value.length == 1 && ".$|()[{^?*+\\".indexOf(ch = regex.charAt(0)) == -1) || (regex.length() == 2 && regex.charAt(0) == '\\' && (((ch = regex.charAt(1))-'0')|('9'-ch)) < 0 && ((ch-'a')|('z'-ch)) < 0 && ((ch-'A')|('Z'-ch)) < 0)) && (ch < Character.MIN_HIGH_SURROGATE || ch > Character.MAX_LOW_SURROGATE)) { int off = 0; int next = 0; boolean limited = limit > 0; ArrayList<String> list = new ArrayList<>(); while ((next = indexOf(ch, off)) != -1) { if (!limited || list.size() < limit - 1) { list.add(substring(off, next)); off = next + 1; } else { // last one //assert (list.size() == limit - 1); list.add(substring(off, value.length)); off = value.length; break; } } // If no match was found, return this if (off == 0) return new String[]{this}; // Add remaining segment if (!limited || list.size() < limit) list.add(substring(off, value.length)); // Construct result int resultSize = list.size(); if (limit == 0) { while (resultSize > 0 && list.get(resultSize - 1).length() == 0) { resultSize--; } } String[] result = new String[resultSize]; return list.subList(0, resultSize).toArray(result); } return Pattern.compile(regex).split(this, limit); }
1.如果我们的需求是要让分隔符号可以兼容中英文逗号
可以用
split(String regex)
比如下面的例子
2.如果我们的需求是取到第一个逗号前面的字符串
适合用
split(String regex, int limit)
以逗号为分割符拼接字符串的技巧
答:
不用那么多if判断,让人思维混乱,直接到最后使用deleteCharAt方法去除最后一个逗号即可。
实现代码如下所示
StringBuffer sb = new StringBuffer(); for (String str: list) { sb.append(str).append(","); } String keywordStr = sb.deleteCharAt(sb.length() - 1).toString();
以上为个人经验,希望能给大家一个参考,也希望大家多多支持脚本之家。