无法将多个正则表达式模式添加到数组列表中

Question

我的目标是在找到模式时给出一个字符串，然后将它们添加到单独的数组中。

例如

我的测试字符串是

String input = "this is a sentence continents=Asia end continents=Europe end continents=Africa end continents=Australia end continents=South America end continents=North America end continents=Antartica end";

结果是

[continents, Asia, continents, Europe, continents, Africa, continents, Australia, continents, South America, continents, North America]

我想要的是将它们添加到单独的数组中，如下所示

[continents, Asia], [continents, Europe], [continents, Africa], [continents, Australia], [continents, South America], [continents, North America], [continents, Antartica]

下面是我的代码：

list = new ArrayList<>();

Pattern pattern = Pattern.compile("continents=(.+?) end ");
Matcher matcher = pattern.matcher(input);

while (matcher.find()) { 
    list.add("continents");
    value = matcher.group(1);
    list.add(value);
}

如有任何帮助，我们将不胜感激。谢谢！

Answer 1

如果我正确理解你的问题，你就快成功了。您只需将每个匹配添加到不同的列表，并将列表添加到外部列表：

    List<List<String>> list = new ArrayList<>();

    Pattern pattern = Pattern.compile("continents=(.+?) end ");
    Matcher matcher = pattern.matcher(input);

    while (matcher.find()) { 
        List<String> innerList = new ArrayList<>();
        innerList.add("continents");
        String value = matcher.group(1);
        innerList.add(value);
        list.add(innerList);
    }

Answer 2

您可以使用

String input = "this is a sentence continents=Asia end continents=Europe end continents=Africa end continents=Australia end continents=South America end continents=North America end continents=Antartica end";
Pattern pattern = Pattern.compile("(continents)=(.+?) end ");
Matcher matcher = pattern.matcher(input);
List<List<String>> lst = new ArrayList<>();
while (matcher.find()){
    lst.add(Arrays.asList(matcher.group(1),matcher.group(2))); 
} 
System.out.println(lst); 
// => [[continents, Asia], [continents, Europe], [continents, Africa], [continents, Australia], [continents, South America], [continents, North America]]

见Java demo

正则表达式现在有两个捕获组，continents被捕获到第1组，名字被捕获到第2组。匹配结果加上Arrays.asList(matcher.group(1),matcher.group(2))到List<List<String>>.

请注意，您也可以使用像 "(continents)=(.+?)\s+end\b" 这样的正则表达式来支持任何空格和 end 作为整个单词，甚至可以在字符串末尾或任何非单词字符之前匹配.

无法将多个正则表达式模式添加到数组列表中

Unable to add multiple regex patterns into array list

java

regex

arrays

arraylist

regex-group