如何用 Java 檢查輸入中的多個正則表示式?


“|” 元字元:Java 正則表示式中的元字元 “|” 允許你匹配多個正則表示式,比如,如果你需要用多個表示式匹配某段輸入文字,你需要用它將它們分隔開,比如

exp1|exp2|exp3

示例

 線上演示

import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class SampleExample {
   public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);
      System.out.println("Enter your input: ");
      String input = sc.nextLine();
      //Regular expression
      String regex = "\d{10}|^[aeiou]";
      //Creating a pattern object
      Pattern pattern = Pattern.compile(regex);
      //Creating a Matcher object
      Matcher matcher = pattern.matcher(input);
      if(matcher.find()) {
         System.out.println(input+" is valid");
      }else {
         System.out.println(input+" is not valid");
      }
   }
}

輸出 1

Enter your input:
9848033228
9848033228 is valid

輸出 2

Enter your input:
an apple a day keeps doctor away
an apple a day keeps doctor away is valid

使用列表物件

另一個解決方案是使用單個模式物件編譯所有正則表示式,並將它們新增到一個列表物件中,然後在輸入文字中查詢匹配項,如下所示:

List list = new ArrayList<>();
list.add(Pattern.compile(regex1));
list.add(Pattern.compile(regex2));
for (Pattern pattern: list) {
   Matcher matcher = pattern.matcher(input);
   if(matcher.find()) {
      . . . . . . . . . . . . . . .
   }else {
      . . . . . . . . . . . . . . .
   }
}

示例

 線上演示

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class MultipleRegex {
   public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);
      System.out.println("Enter your input: ");
      String input = sc.nextLine();
      //Regular expressions
      String regex1 = "\d{10}";
      String regex2 = "^[aeiou]";
      //Creating a pattern objects
      Pattern pattern1 = Pattern.compile(regex1);
      Pattern pattern2 = Pattern.compile(regex2);
      //Creating an List object
      List<Pattern> patterns = new ArrayList<>();
      patterns.add(pattern1);
      patterns.add(pattern2);
      for (Pattern pattern: patterns) {
         Matcher matcher = pattern.matcher(input);
         if(matcher.find()) {
            System.out.println("For regex "+pattern.pattern()+" "+input+" is valid");
         } else {
            System.out.println("For regex "+pattern.pattern()+" "+input+" is not valid");
         }
      }
   }
}

輸出 1

Enter your input:
9848033228
For regex \d{10} 9848033228 is valid
For regex ^[aeiou] 9848033228 is not valid

輸出 2

Enter your input:
an apple a day keeps doctor away
For regex \d{10} an apple a day keeps doctor away is not valid
For regex ^[aeiou] an apple a day keeps doctor away is valid

更新於: 2020 年 1 月 10 日

5K+ 瀏覽

開啟您的職業生涯

完成課程,獲得認證

開始
廣告