This PR is related to BAEL-7528 (#15865)

* Update pom.xml

Add:         <module>core-java-string-operations-8</module>

* This commit is related to BAEL-7528

This commit aims to add a new module "core-java-string-operations-8" to submit a test class "EmailAndPhoneMaskingUnitTest"

core-java-modules/core-java-string-operations-8/README.md

@@ -0,0 +1,2 @@
+
+### Relevant Articles:

core-java-modules/core-java-string-operations-8/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-java-string-operations-8</artifactId>
+    <name>core-java-string-operations-8</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${apache.commons.lang3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-text</artifactId>
+            <version>${commons-text.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.liquibase</groupId>
+            <artifactId>liquibase-core</artifactId>
+            <version>4.9.1</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>5.8.1</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.liquibase</groupId>
+            <artifactId>liquibase-core</artifactId>
+            <version>4.9.1</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.2</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>${maven.compiler.source}</source>
+                    <target>${maven.compiler.target}</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <properties>
+        <maven.compiler.source>11</maven.compiler.source>
+        <maven.compiler.target>11</maven.compiler.target>
+        <apache.commons.lang3.version>3.13.0</apache.commons.lang3.version>
+        <commons-text.version>1.10.0</commons-text.version>
+    </properties>
+
+</project>

core-java-modules/core-java-string-operations-8/src/test/java/com/baeldung/emailandphonemasking/EmailAndPhoneMaskingUnitTest.java

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+package com.baeldung.emailandphonemasking;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class EmailAndPhoneMaskingUnitTest {
+
+
+    String phoneNumber = "+12344567890";
+    String expectedMaskedPhoneNumber = "+*******7890";
+    String email = "testemailaddress@example.com";
+    String expectedMaskedEmail = "te**************@example.com";
+
+    @Test
+    public void givenEmailAddress_whenUsingStringManipulation_thenMaskEmail() {
+        int atIndex = email.indexOf('@');
+        String repeatedString = IntStream.range(0, atIndex - 2).mapToObj(i -> "*").collect(Collectors.joining());
+        String maskedPart = email.substring(0, atIndex - repeatedString.length()) + repeatedString;
+        String maskedEmail = maskedPart + email.substring(atIndex);
+        assertEquals(expectedMaskedEmail, maskedEmail);
+    }
+
+    @Test
+    public void givenEmailAddress_whenUsingRegex_thenMaskEmail() {
+        int atIndex = email.indexOf('@');
+        String regex = "(.{2})(.*)(@.*)";
+        String repeatedAsterisks = "*".repeat(atIndex - 2);
+        String maskedEmail = email.replaceAll(regex, "$1" + repeatedAsterisks + "$3");
+        assertEquals(expectedMaskedEmail, maskedEmail);
+    }
+
+
+    @Test
+    public void givenPhoneNumber_whenUsingStringManipulation_thenMaskPhone() {
+        String maskedPhoneNumber = phoneNumber.replaceAll("\\d(?=\\d{4})", "*");
+        assertEquals(expectedMaskedPhoneNumber, maskedPhoneNumber);
+    }
+
+    @Test
+    public void givenPhoneNumber_whenUsingRegex_thenMaskPhone() {
+        int lastDigitsIndex = phoneNumber.length() - 5;
+        String regex = "(\\+)(\\d+)(\\d{4})";
+        String repeatedAsterisks = "*".repeat(Math.max(0, lastDigitsIndex));
+        String maskedPhoneNumber = phoneNumber.replaceAll(regex, "$1" + repeatedAsterisks + "$3");
+        assertEquals(expectedMaskedPhoneNumber, maskedPhoneNumber);
+    }
+
+
+}

core-java-modules/pom.xml

@@ -199,6 +199,7 @@
         <module>core-java-string-operations-2</module>
         <module>core-java-string-operations-6</module>
         <module>core-java-string-operations-7</module>
+        <module>core-java-string-operations-8</module>
         <module>core-java-regex</module>
         <module>core-java-regex-2</module>
         <module>core-java-regex-3</module>