java - 为以特定字符串开始和结束的查找语句创建正则表达式，特定字符串除外

Question

我尝试了很多，但无法找到准确的正则表达式。

String str = "this cat is small. dog is pet anmial. this mouse is small.this toy is small. this is a cat and it's small. this is dog and it's small.  ";
Pattern ptr = Pattern.compile("this.*((?!(cat).)*).*small");

我想提取字符串，以this开头，以small结尾的字符串 并且不应包含 cat 之间的任何位置，使用此正则表达式无法获得所需的输出。

我想要的输出是:

                this mouse is small
                this toy is small  
                this is dog and it's small

Answer 1

String str = "this cat is small. dog is pet anmial. this mouse is small.this toy is small.";
Pattern ptr = Pattern.compile("this\\s(?!cat).*?small");
Matcher matcher=ptr.matcher(str);
while (matcher.find()) {
    System.out.println(matcher.group());
}

输出:

this mouse is small
this toy is small

this\\s(?!cat).*?small :以 this 开始，以 small

结束

(?!cat) :如果前面没有猫则匹配

.*? :匹配任何字符，尽可能少的次数

RegexDemo

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更新:

Regex demo this((?!cat).)*?small

输出:

this mouse is small
this toy is small
this is dog and it's small

(?!cat). :它将匹配任何字符直到换行符