Java Scanner findAll() Method

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Description

The Java Scanner findAll(Pattern pattern) method returns a stream of match results from this scanner. The stream contains the same results in the same order that would be returned by calling findWithinHorizon(pattern, 0) and then match() successively as long as findWithinHorizon() finds matches. The resulting stream is sequential and ordered. All stream elements are non-null.

Declaration

Following is the declaration for java.util.Scanner.findAll() method

public Stream<MatchResult> findAll(Pattern pattern)

Parameters

pattern − the pattern to be matched

Return Value

This method returns a sequential stream of match results.

Exception

NullPointerException − if pattern is null

IllegalStateException − if this scanner is closed

Java Scanner findInLine(String pattern) Method

Description

The java Scanner findAll(String pattern) method returns a stream of match results that match the provided pattern string.

Declaration

Following is the declaration for java.util.Scanner.findAll(String pattern) method

public Stream<MatchResult> findAll(String pattern)

Parameters

pattern − a string specifying the pattern to search for

Return Value

This method returns the text that matched the specified pattern.

Exception

NullPointerException − if patString is null

IllegalStateException − if this scanner is closed

PatternSyntaxException − if the regular expression's syntax is invalid

Finding multiple patterns Using Scanner on a String Example

The following example shows the usage of Java Scanner findAll(Pattern pattern) method to get a stream of matched result of pattern in a given string. We've created a scanner object using a given string. We've retrieved a stream using findAll(Pattern) method. A stream is then iterated to print the result. Then we printed the string using scanner.nextLine() method.

package com.tutorialspoint;

import java.util.Scanner;
import java.util.regex.MatchResult;
import java.util.regex.Pattern;
import java.util.stream.Stream;

public class ScannerDemo {
   public static void main(String[] args) {

      String s = "Hello World! 3 + 3.0 = 6";

      // create a new scanner with the specified String Object
      Scanner scanner = new Scanner(s);

      Stream<MatchResult> stream = scanner.findAll(Pattern.compile(".ello"));
      
      stream.forEach(i -> System.out.println(i.group()));
      
      // print the next line of the string
      System.out.println(scanner.nextLine());

      // close the scanner
      scanner.close();
   }
}

Output

Let us compile and run the above program, this will produce the following result −

Hello
 World! 3 + 3.0 = 6

Finding multiple String patterns Using Scanner on a String Example

The following example shows the usage of Java Scanner findAll(String pattern) method to get a stream of matched result of pattern in a given string. We've created a scanner object using a given string. We've retrieved a stream using findAll(String) method. A stream is then iterated to print the result. Then we printed the string using scanner.nextLine() method.

package com.tutorialspoint;

import java.util.Scanner;
import java.util.regex.MatchResult;
import java.util.stream.Stream;

public class ScannerDemo {
   public static void main(String[] args) {

      String s = "Hello World! 3 + 3.0 = 6";

      // create a new scanner with the specified String Object
      Scanner scanner = new Scanner(s);

      Stream<MatchResult> stream = scanner.findAll("World");
      
      stream.forEach(i -> System.out.println(i.group()));
      
      // print the next line of the string
      System.out.println(scanner.nextLine());

      // close the scanner
      scanner.close();
   }
}

Output

Let us compile and run the above program, this will produce the following result −

World
! 3 + 3.0 = 6

Finding multiple patterns Using Scanner on User Input Example

The following example shows the usage of Java Scanner findAll(String pattern) method to get a stream of matched result of pattern in a given string. We've created a scanner object using System.in class. We've retrieved a stream using findAll(String) method. A stream is then iterated to print the result. Then we printed the string using scanner.nextLine() method.

package com.tutorialspoint;

import java.util.Scanner;
import java.util.regex.MatchResult;
import java.util.stream.Stream;

public class ScannerDemo {
   public static void main(String[] args) {

      // create a new scanner with the System input
      Scanner scanner = new Scanner(System.in);

      Stream<MatchResult> stream = scanner.findAll("World");
      
      stream.forEach(i -> System.out.println(i.group()));

      // close the scanner
      scanner.close();
   }
}

Output

Let us compile and run the above program, this will produce the following result − (where we've entered Hello World and pressed enter key.)

Hello World
World