baeldung-articles : BAEL-6752 (#16195)

* baeldung-articles : BAEL-6752

When to Use Setter Methods or Constructors for Setting a Variable's Value in Java.

* baeldung-articles : BAEL-6752

When to Use Setter Methods or Constructors for Setting a Variable's Value in Java.

* Updating ConstructorsVersusSetterMethodsUnitTest.java

Rename functions

core-java-modules/core-java-lang-oop-constructors-2/src/main/java/com/baeldung/objectcreation/constructorversussettermethod/Product.java

@@ -0,0 +1,26 @@
+package com.baeldung.constructorversussettermethod;
+
+public class Product {
+    private String name;
+    private double price;
+    private String category;
+
+    public Product(String name, double price, String category) {
+        this.name = name;
+        this.price = price;
+        this.category = category;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public double getPrice() {
+        return price;
+    }
+
+    public String getCategory() {
+        return category;
+    }
+}
+

core-java-modules/core-java-lang-oop-constructors-2/src/main/java/com/baeldung/objectcreation/constructorversussettermethod/User.java

@@ -0,0 +1,31 @@
+package com.baeldung.constructorversussettermethod;
+
+public class User {
+    private String username;
+    private String password;
+
+    public String getUsername() {
+        return username;
+    }
+
+    public void setUsername(String username) {
+        if (username.matches("[a-zA-Z0-9_]+")) {
+            this.username = username;
+        } else {
+            throw new IllegalArgumentException("Invalid username format");
+        }
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public void setPassword(String password) {
+        if (password.length() >= 8) {
+            this.password = password;
+        } else {
+            throw new IllegalArgumentException("Password must be at least 8 characters long");
+        }
+    }
+}
+

core-java-modules/core-java-lang-oop-constructors-2/src/test/java/com/baeldung/objectcreation/constructorversussettermethod/ConstructorsVersusSetterMethodsUnitTest.java

@@ -0,0 +1,30 @@
+package com.baeldung.constructorversussettermethod;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class ConstructorsVersusSetterMethodsUnitTest {
+    @Test
+    public void givenNewUser_whenSettingUsername_thenUsernameIsSet() {
+        User user = new User();
+        user.setUsername("john_doe");
+        assertEquals("john_doe", user.getUsername());
+    }
+
+    @Test
+    public void givenNewUser_whenSettingPassword_thenPasswordIsSet() {
+        User user = new User();
+        user.setPassword("strongPassword123");
+        assertEquals("strongPassword123", user.getPassword());
+    }
+
+    @Test
+    public void givenProductDetails_whenCreatingProductWithConstructor_thenProductHasCorrectAttributes() {
+        Product product = new Product("Smartphone", 599.99, "Electronics");
+        assertEquals("Smartphone", product.getName());
+        assertEquals(599.99, product.getPrice(), 0.001);
+        assertEquals("Electronics", product.getCategory());
+    }
+}
+