在Java中如何使用Pattern和Matcher进行正则匹配_正则表达式在Java中的实际应用解析

import java.util.regex.*;

public class RegexExample {
    public static void main(String[] args) {
        String text = "订单编号：20240915，金额：998元";
        Pattern pattern = Pattern.compile("\d+");
        Matcher matcher = pattern.matcher(text);

        while (matcher.find()) {
            System.out.println("找到数字：" + matcher.group());
        }
    }
}

String input = "123abc";
Pattern p = Pattern.compile("\d+");

System.out.println(p.matcher(input).matches());   // false（不全匹配）
System.out.println(p.matcher(input).find());       // true（有子串匹配）
System.out.println(p.matcher(input).lookingAt());  // true（开头匹配）

String dateStr = "注册时间：2024-09-15";
Pattern datePattern = Pattern.compile("(\d{4})-(\d{2})-(\d{2})");
Matcher m = datePattern.matcher(dateStr);

if (m.find()) {
    System.out.println("年：" + m.group(1)); // 2024
    System.out.println("月：" + m.group(2)); // 09
    System.out.println("日：" + m.group(3)); // 15
}

String email = "user@example.com";
boolean isValid = Pattern.matches("\w+@\w+\.\w+", email);

String content = "这个产品很垃圾，太差了";
Pattern sensitive = Pattern.compile("垃圾|差");
Matcher m = sensitive.matcher(content);
String filtered = m.replaceAll("*");
// 结果："这个产品很*，太*了"

Pattern comma = Pattern.compile(",\s*");
String[] parts = comma.split("a, b, c , d");
// 正确处理空格，结果：[a, b, c, d]