[BAEL-5976]: Extract Values using AssertJ in Java (#13105)

JIRA: https://jira.baeldung.com/browse/BAEL-5976

testing-modules/assertion-libraries/src/main/java/com/baeldung/assertj/extracting/Address.java

@@ -0,0 +1,25 @@
+package com.baeldung.assertj.extracting;
+
+class Address {
+    private String street;
+    private String city;
+    private ZipCode zipCode;
+
+    Address(String street, String city, ZipCode zipCode) {
+        this.street = street;
+        this.city = city;
+        this.zipCode = zipCode;
+    }
+
+    public String getStreet() {
+        return street;
+    }
+
+    public String getCity() {
+        return city;
+    }
+
+    public ZipCode getZipCode() {
+        return zipCode;
+    }
+}

testing-modules/assertion-libraries/src/main/java/com/baeldung/assertj/extracting/Person.java

@@ -0,0 +1,25 @@
+package com.baeldung.assertj.extracting;
+
+class Person {
+    private String firstName;
+    private String lastName;
+    private Address address;
+
+    Person(String firstName, String lastName, Address address) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+        this.address = address;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public Address getAddress() {
+        return address;
+    }
+}

testing-modules/assertion-libraries/src/main/java/com/baeldung/assertj/extracting/ZipCode.java

@@ -0,0 +1,13 @@
+package com.baeldung.assertj.extracting;
+
+class ZipCode {
+    private long zipcode;
+
+    ZipCode(long zipcode) {
+        this.zipcode = zipcode;
+    }
+
+    public long getZipcode() {
+        return zipcode;
+    }
+}