Java java.util.regex.Matcher.usePattern()用法及代碼示例

描述

這個java.util.regex.Matcher.usePattern(Pattern newPattern)方法更改此匹配器用於查找匹配項的模式。

聲明

以下是聲明java.util.regex.Matcher.usePattern(Pattern newPattern)方法。

public Matcher usePattern(Pattern newPattern)

參數

• newPattern- 此匹配器使用的新模式。

返回值

這個匹配器。

異常

• IllegalArgumentException − 如果 newPattern 為空。

示例

下麵的例子展示了 java.util.regex.Matcher.usePattern(Pattern newPattern) 方法的用法。

package com.tutorialspoint;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class MatcherDemo {
   private static String REGEX = "(a*b)(foo)";
   private static String INPUT = "aabfooaabfooabfoob";

   public static void main(String[] args) {
      // create a pattern
      Pattern pattern = Pattern.compile(REGEX);
      
      // get a matcher object
      Matcher matcher = pattern.matcher(INPUT); 
      
      while(matcher.find()) {
         //Prints the start index of the subsequence captured by the given group.
         System.out.println("Second Capturing Group, (foo) Match String start():"+matcher.start(1));
      }  
      matcher.reset();
      matcher.usePattern(Pattern.compile("(a*b)(foob)"));
      
      while(matcher.find()) {
         //Prints the start index of the subsequence captured by the given group.
         System.out.println("Second Capturing Group, (fooab) Match String start():"+matcher.start(1));
      }  
   }
}

讓我們編譯並運行上麵的程序，這將產生以下結果 -

Second Capturing Group, (foo) Match String start():0
Second Capturing Group, (foo) Match String start():6
Second Capturing Group, (foo) Match String start():12
Second Capturing Group, (fooab) Match String start():12