Matcher appendReplacement(StringBuffer, String) method in Java with Examples
The appendReplacement(StringBuffer, String) method of Matcher Class behaves as a append-and-replace method. This method reads the input string and replace it with the matched pattern in the matcher string.
Syntax:
public Matcher
appendReplacement(StringBuffer buffer,
String stringToBeReplaced)
Parameters: This method takes two parameters:
- buffer: which is the StringBuffer that stores the target string.
- stringToBeReplaced: which is the String to be replaced in the matcher.
Return Value: This method returns a Matcher with the target String replaced.
Exception: This method throws following exceptions:
- IllegalStateException: If no match has yet been attempted, or if the previous match operation failed
- IllegalArgumentException: If the replacement string refers to a named-capturing group that does not exist in the pattern
- IndexOutOfBoundsException: If the replacement string refers to a capturing group that does not exist in the pattern
Below examples illustrate the Matcher.appendReplacement() method:
Example 1:
// Java code to illustrate appendReplacement() 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 // using appendReplacement() method while (matcher.find()) { matcher.appendReplacement(buffer, stringToBeReplaced); } matcher.appendTail(buffer); // Print the replaced matcher System.out.println("After Replacement: " + buffer.toString()); } } |
Output:
Before Replacement: GeeksForGeeks Geeks for For Geeks Geek After Replacement: GEEKSForGEEKS GEEKS for For GEEKS Geek
Example 2:
// Java code to illustrate appendReplacement() 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 // using appendReplacement() method while (matcher.find()) { matcher.appendReplacement(buffer, stringToBeReplaced); } matcher.appendTail(buffer); // Print the replaced matcher System.out.println("After Replacement: " + buffer.toString()); } } |
Output:
Before Replacement: FGF FGF FGF FGF After Replacement: GFG GFG GFG GFG
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