import java.util.regex.*;

public class Main {
  public static void main(String[] args) {
    String input = "The temperature is 25.6 degrees Celsius.";

    // Regular expression pattern for matching floating point numbers
    Pattern pattern = Pattern.compile("\\d+\\.\\d+");
    Matcher matcher = pattern.matcher(input);

    // Find all matches
    while (matcher.find()) {
      String match = matcher.group();
      System.out.println("Match: " + match);
    }
  }
}

In this example, we create a regular expression pattern "\\d+\\.\\d+" which matches floating point numbers. This pattern consists of the following components:

• \\d+ matches one or more digits.
• \\. matches the decimal point.
• \\d+ matches one or more digits after the decimal point.

We then create a Matcher object using the input string and the pattern. We can use the find() method to find all occurrences of the pattern in the input string. The group() method returns the actual matched string.

When you run this code, it will output:

Match: 25.6

This example demonstrates how to use regular expressions to match floating point numbers in Java.