Java中的 Matcher appendTail(StringBuffer) 方法及示例

Matcher 类的appendTail(StringBuffer)方法表现为追加和替换方法。此方法读取输入字符串并将其附加到给定 StringBuffer 的尾部位置。

句法：

public StringBuffer appendTail(StringBuffer buffer)

参数：此方法采用参数缓冲区，该缓冲区是存储目标字符串的 StringBuffer。

返回值：此方法返回一个替换了目标字符串的StringBuffer 。

下面的示例说明了 Matcher.appendTail() 方法：

示例 1：

// Java code to illustrate appendTail() method
  
import java.util.regex.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // Get the regex to be checked
        String regex = "(Geeks)";
  
        // Create a pattern from regex
        Pattern pattern = Pattern.compile(regex);
  
        // Get the String to be matched
        String stringToBeMatched = "GeeksForGeeks Geeks for For Geeks Geek";
  
        // Create a matcher for the input String
        Matcher matcher = pattern.matcher(stringToBeMatched);
  
        System.out.println("Before Replacement: " + stringToBeMatched);
  
        // Get the String to be replaced
        String stringToBeReplaced = "GEEKS";
        StringBuffer buffer = new StringBuffer();
  
        // Replace every matched pattern
        // with the target String
        while (matcher.find()) {
            matcher.appendReplacement(buffer,
                                      stringToBeReplaced);
        }
  
        // Add the replaced string at the tail
        // using the appendTail() method
        matcher.appendTail(buffer);
  
        // Print the replaced matcher
        System.out.println("After Replacement: "
                           + buffer.toString());
    }
}

输出：

Before Replacement: GeeksForGeeks Geeks for For Geeks Geek
After Replacement: GEEKSForGEEKS GEEKS for For GEEKS Geek

示例 2：

// Java code to illustrate appendTail() method
  
import java.util.regex.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // Get the regex to be checked
        String regex = "(FGF)";
  
        // Create a pattern from regex
        Pattern pattern
            = Pattern.compile(regex);
  
        // Get the String to be matched
        String stringToBeMatched
            = "FGF FGF FGF FGF";
  
        // Create a matcher for the input String
        Matcher matcher
            = pattern.matcher(stringToBeMatched);
  
        System.out.println("Before Replacement: "
                           + stringToBeMatched);
  
        // Get the String to be replaced
        String stringToBeReplaced = "GFG";
        StringBuffer buffer = new StringBuffer();
  
        // Replace every matched pattern
        // with the target String
        while (matcher.find()) {
            matcher.appendReplacement(buffer,
                                      stringToBeReplaced);
        }
  
        // Add the replaced string at the tail
        // using the appendTail() method
        matcher.appendTail(buffer);
  
        // Print the replaced matcher
        System.out.println("After Replacement: "
                           + buffer.toString());
    }
}

输出：

Before Replacement: FGF FGF FGF FGF
After Replacement: GFG GFG GFG GFG

参考： https://docs.oracle.com/javase/9/docs/api/ Java/util/regex/Matcher.html#appendTail-java.lang.StringBuffer-