eugenp · bhaskar16 · Apr 7, 2025
diff --git a/libraries-data/pom.xml b/libraries-data/pom.xml
@@ -163,6 +163,12 @@
             <version>${flink.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.1</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>

diff --git a/libraries-data/src/main/java/com/baeldung/gson/pojo/User.java b/libraries-data/src/main/java/com/baeldung/gson/pojo/User.java
@@ -0,0 +1,64 @@
+package com.baeldung.gson.pojo;
+
+import com.google.gson.annotations.Expose;
+import com.google.gson.annotations.SerializedName;
+
+public class User {
+
+    @Expose
+    @SerializedName(value = "firstName", alternate = { "fullName", "name" })
+    String name;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(int age) {
+        this.age = age;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        this.id = id;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+
+    @Expose
+    int age;
+
+    @Expose(serialize = true, deserialize = false)
+    public long id;
+
+    @Expose(serialize = false, deserialize = false)
+    private String email;
+
+    // Constructors, Getters, and Setters
+    public User(String name, int age, String email) {
+        this.name = name;
+        this.age = age;
+        this.email = email;
+    }
+
+    @Override
+    public String toString() {
+        return "User{" + "name='" + name + '\'' + ", age=" + age + ", id=" + id + ", email='" + email + '\'' + '}';
+    }
+}
diff --git a/libraries-data/src/test/java/com/baeldung/gson/GsonUnitTest.java b/libraries-data/src/test/java/com/baeldung/gson/GsonUnitTest.java
@@ -0,0 +1,60 @@
+package com.baeldung.gson;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.gson.pojo.User;
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+
+public class GsonUnitTest {
+
+    @Test
+    public void testSerialization() {
+        User user = new User("John Doe", 30, "john.doe@example.com");
+        user.setId(12345L);
+
+        Gson gson = new GsonBuilder().excludeFieldsWithoutExposeAnnotation()
+          .create();
+        String json = gson.toJson(user);
+
+        // Verify that name, age, and id are serialized, but email is not
+        assertEquals("{\"firstName\":\"John Doe\",\"age\":30,\"id\":12345}", json);
+    }
+
+    @Test
+    public void testDeserialization() {
+        String jsonInput = "{\"firstName\":\"Jane Doe\",\"age\":25,\"id\":67890,\"email\":\"jane.doe@example.com\"}";
+
+        Gson gson = new GsonBuilder().excludeFieldsWithoutExposeAnnotation()
+          .create();
+        User user = gson.fromJson(jsonInput, User.class);
+
+        // Verify that name and age are deserialized, but email and id are not
+        assertEquals("Jane Doe", user.getName());
+        assertEquals(25, user.getAge());
+        assertEquals(0, user.getId());
+        assertNull(user.getEmail());
+    }
+
+    @Test
+    public void testDeserializationWithAlternateNames() {
+        String jsonInput1 = "{\"firstName\":\"Jane Doe\",\"age\":25,\"id\":67890,\"email\":\"jane.doe@example.com\"}";
+        String jsonInput2 = "{\"fullName\":\"John Doe\",\"age\":30,\"id\":12345,\"email\":\"john.doe@example.com\"}";
+        String jsonInput3 = "{\"name\":\"Alice\",\"age\":28,\"id\":54321,\"email\":\"alice@example.com\"}";
+
+        Gson gson = new GsonBuilder().excludeFieldsWithoutExposeAnnotation()
+          .create();
+
+        User user1 = gson.fromJson(jsonInput1, User.class);
+        User user2 = gson.fromJson(jsonInput2, User.class);
+        User user3 = gson.fromJson(jsonInput3, User.class);
+
+        // Verify that the name field is correctly deserialized from different JSON field names
+        assertEquals("Jane Doe", user1.getName());
+        assertEquals("John Doe", user2.getName());
+        assertEquals("Alice", user3.getName());
+    }
+}