如何检查字符串列表中的特定单词是否包含在字符串中，但不应该在任何其他单词之间？

Question

I need to check if any string from a string list matches wholly (whole word search) within the input string ie it should not match the word in between characters. eg check the code below:

String input = "i was hoping the number";
String[] valid = new String[] { "nip", "pin" };
if (Arrays.stream(valid).anyMatch(input::contains)) {
    System.out.println("valid");
}

My output is valid , which is not correct. It is fetching the pin string from the hoping word. I should be able to match only if the pin word is separate.

Answer 1

Do it as follows:

import java.util.Arrays;
import java.util.regex.Pattern;

public class Main {
    public static void main(String[] args) {
        String input = "i was hoping the number";
        String[] valid = new String[] { "nip", "pin" };
        if (Arrays.stream(valid).anyMatch(p -> Pattern.compile("\\b" + p + "\\b").matcher(input).find())) {
            System.out.println("valid");
        }
    }
}

Note that \\b is used for word boundary which I have added before and after the matching words to create word boundary for them.

Some more tests:

import java.util.Arrays;
import java.util.regex.Pattern;

public class Main {
    public static void main(String[] args) {
        String[] testStrings = { "i was hoping the number", "my pin is 123", "the word, turnip ends with nip",
                "turnip is a vegetable" };
        String[] valid = new String[] { "nip", "pin" };
        for (String input : testStrings) {
            if (Arrays.stream(valid).anyMatch(p -> Pattern.compile("\\b" + p + "\\b").matcher(input).find())) {
                System.out.println(input + " => " + "valid");
            } else {
                System.out.println(input + " => " + "invalid");
            }
        }
    }
}

Output:

i was hoping the number => invalid
my pin is 123 => valid
the word, turnip ends with nip => valid
turnip is a vegetable => invalid

Solution without using Stream API:

import java.util.regex.Pattern;

public class Main {
    public static void main(String[] args) {
        String input = "i was hoping the number";
        String[] valid = new String[] { "nip", "pin" };
        for (String toBeMatched : valid) {
            if (Pattern.compile("\\b" + toBeMatched + "\\b").matcher(input).find()) {
                System.out.println("valid");
            }
        }
    }
}