Método Matcher usePattern (Patrón) en Java con ejemplos

El método usePattern() de Matcher Class se utiliza para hacer coincidir el patrón con este comparador. Sintaxis:

public Matcher usePattern(Pattern newPattern)

Parámetros: Este método toma un parámetro newPattern que es el nuevo patrón a configurar. Valor de retorno: este método devuelve un Matcher con el nuevo patrón. Excepción: este método arroja IllegalArgumentException si newPattern es nulo. Los siguientes ejemplos ilustran el método Matcher.usePattern(): Ejemplo 1: 

// Java code to illustrate usePattern() 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";
 
        // Create a matcher for the input String
        Matcher matcher
            = pattern
                  .matcher(stringToBeMatched);
 
        // Get the new Pattern
        String newPattern = "GFG";
 
        // Get the Pattern using pattern method
        System.out.println("Old Pattern: "
                           + matcher.pattern());
 
        // Set the newPattern using usePattern() method
        matcher = matcher
                      .usePattern(
                          Pattern
                              .compile(newPattern));
 
        // Get the Pattern
        // using pattern method
        System.out.println("New Pattern: "
                           + matcher.pattern());
    }
}

Old Pattern: Geeks
New Pattern: GFG

Ejemplo 2: 

// Java code to illustrate usePattern() method
 
import java.util.regex.*;
 
public class GFG {
    public static void main(String[] args)
    {
 
        // Get the regex to be checked
        String regex = "GFG";
 
        // Create a pattern from regex
        Pattern pattern
            = Pattern.compile(regex);
 
        // Get the String to be matched
        String stringToBeMatched
            = "GFGFGFGFGFGFGFGFGFG";
 
        // Create a matcher for the input String
        Matcher matcher
            = pattern
                  n.matcher(stringToBeMatched);
 
        // Get the new Pattern
        String newPattern = "Geeks";
 
        // Get the Pattern using pattern method
        System.out.println("Old Pattern: "
                           + matcher.pattern());
 
        // Set the newPattern using usePattern() method
        matcher = matcher
                      .usePattern(
                          Pattern
                              .compile(newPattern));
 
        // Get the Pattern
        // using pattern method
        System.out.println("New Pattern: "
                           + matcher.pattern());
    }
}

Old Pattern: GFG
New Pattern: Geeks

Referencia: documento de Oracle