From 923de8ee4ac460e8bbdb3ccae5441ee601d8e745 Mon Sep 17 00:00:00 2001
From: Bhaskar <dastidar.bhaskar@gmail.com>
Date: Sun, 20 Apr 2025 11:16:51 +0530
Subject: [PATCH] [BAEL-6553] Gson Expose and SerializedName tests

---
 json-modules/gson-3/pom.xml                   | 33 ++++++++++
 json-modules/gson-3/src/main/java/User.java   | 61 +++++++++++++++++++
 .../gson-3/src/test/java/GsonUnitTest.java    | 56 +++++++++++++++++
 json-modules/pom.xml                          |  1 +
 4 files changed, 151 insertions(+)
 create mode 100644 json-modules/gson-3/pom.xml
 create mode 100644 json-modules/gson-3/src/main/java/User.java
 create mode 100644 json-modules/gson-3/src/test/java/GsonUnitTest.java

diff --git a/json-modules/gson-3/pom.xml b/json-modules/gson-3/pom.xml
new file mode 100644
index 000000000000..1dd8cd3251db
--- /dev/null
+++ b/json-modules/gson-3/pom.xml
@@ -0,0 +1,33 @@
+<?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>
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>json-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>gson-3</artifactId>
+
+    <properties>
+        <gson-version>2.12.1</gson-version>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.1</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.google.code.gson</groupId>
+            <artifactId>gson</artifactId>
+            <version>${gson-version}</version>
+            <scope>compile</scope>
+        </dependency>
+    </dependencies>
+
+</project>
\ No newline at end of file
diff --git a/json-modules/gson-3/src/main/java/User.java b/json-modules/gson-3/src/main/java/User.java
new file mode 100644
index 000000000000..894a3fbeb052
--- /dev/null
+++ b/json-modules/gson-3/src/main/java/User.java
@@ -0,0 +1,61 @@
+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;
+
+    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 + '\'' + '}';
+    }
+}
\ No newline at end of file
diff --git a/json-modules/gson-3/src/test/java/GsonUnitTest.java b/json-modules/gson-3/src/test/java/GsonUnitTest.java
new file mode 100644
index 000000000000..610ce901f27f
--- /dev/null
+++ b/json-modules/gson-3/src/test/java/GsonUnitTest.java
@@ -0,0 +1,56 @@
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+import org.junit.jupiter.api.Test;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+
+public class GsonUnitTest {
+    @Test
+    public void givenUserObject_whenSerialized_thenCorrectJsonProduced() {
+        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 givenJsonInput_whenDeserialized_thenCorrectUserObjectProduced() {
+        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 givenJsonWithAlternateNames_whenDeserialized_thenCorrectNameFieldMapped() {
+        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());
+    }
+}
\ No newline at end of file
diff --git a/json-modules/pom.xml b/json-modules/pom.xml
index c08d4215a666..debb8c7cdea8 100644
--- a/json-modules/pom.xml
+++ b/json-modules/pom.xml
@@ -23,6 +23,7 @@
         <module>json-path</module>
         <module>gson</module>
         <module>gson-2</module>
+        <module>gson-3</module>
     </modules>
 
     <build>