codebase/introduction-to-spring-data-mongodb [BAEL-8677] [Improvement] (#18236)

* add domain model and repository

* fix: Document parameter

* update active datatype and add repository methods

* add test cases for AuthorRepository

* update assertions

* update assertion

* add main application

* fix: bean conflicts

* add test cases for MongoTemplate

Author: hardikSinghBehl

persistence-modules/spring-data-mongodb/pom.xml

@@ -46,6 +46,22 @@
             <version>${embed.mongo.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.instancio</groupId>
+            <artifactId>instancio-junit</artifactId>
+            <version>${instancio.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-testcontainers</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>mongodb</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <build>
@@ -66,10 +82,20 @@
                     </execution>
                 </executions>
             </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>21</source>
+                    <target>21</target>
+                </configuration>
+            </plugin>
         </plugins>
     </build>
 
     <properties>
+        <spring-boot.version>3.4.1</spring-boot.version>
+        <instancio.version>5.3.0</instancio.version>
         <querydsl.version>5.1.0</querydsl.version>
         <mysema.maven.version>1.1.3</mysema.maven.version>
         <projectreactor.version>3.5.4</projectreactor.version>

persistence-modules/spring-data-mongodb/src/main/java/com/baeldung/Application.java

@@ -0,0 +1,21 @@
+package com.baeldung;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.ComponentScan;
+
+/**
+ * Main Spring Boot class that scans only the repository package to avoid
+ * bean conflicts with shared codebase's manual MongoDB configuration.
+ * This ensures that MongoDataAutoConfiguration handles MongoDB setup while preventing
+ * duplicate bean definitions from external config classes.
+ */
+@SpringBootApplication
+@ComponentScan(basePackages = "com.baeldung.repository")
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+
+}

persistence-modules/spring-data-mongodb/src/main/java/com/baeldung/model/Author.java

@@ -0,0 +1,67 @@
+package com.baeldung.model;
+
+import org.springframework.data.annotation.Id;
+import org.springframework.data.mongodb.core.index.Indexed;
+import org.springframework.data.mongodb.core.mapping.Document;
+import org.springframework.data.mongodb.core.mapping.Field;
+
+import java.util.UUID;
+
+@Document(collection = "authors")
+public class Author {
+
+    @Id
+    private UUID id;
+
+    @Field(name = "full_name")
+    private String name;
+
+    @Indexed(unique = true)
+    private String email;
+
+    @Field(name = "article_count")
+    private Integer articleCount;
+
+    private Boolean active;
+
+    public UUID getId() {
+        return id;
+    }
+
+    public void setId(UUID id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+
+    public Integer getArticleCount() {
+        return articleCount;
+    }
+
+    public void setArticleCount(Integer articleCount) {
+        this.articleCount = articleCount;
+    }
+
+    public Boolean isActive() {
+        return active;
+    }
+
+    public void setActive(Boolean active) {
+        this.active = active;
+    }
+
+}

persistence-modules/spring-data-mongodb/src/main/java/com/baeldung/repository/AuthorRepository.java

@@ -0,0 +1,23 @@
+package com.baeldung.repository;
+
+import com.baeldung.model.Author;
+import org.springframework.data.mongodb.repository.MongoRepository;
+import org.springframework.data.mongodb.repository.Query;
+
+import java.util.List;
+import java.util.Optional;
+import java.util.UUID;
+
+public interface AuthorRepository extends MongoRepository<Author, UUID> {
+
+    Optional<Author> findByEmail(String email);
+
+    List<Author> findByActiveTrueAndArticleCountGreaterThanEqual(int articleCount);
+
+    @Query("{ 'article_count': { $gte: ?0, $lte: ?1 }, 'active': true }")
+    List<Author> findActiveAuthorsInArticleRange(int minArticles, int maxArticles);
+
+    @Query(value = "{ 'active': true }", fields = "{ 'email': 1 }")
+    List<Author> findActiveAuthorEmails();
+
+}

persistence-modules/spring-data-mongodb/src/test/java/com/baeldung/TestcontainersConfiguration.java

@@ -0,0 +1,25 @@
+package com.baeldung;
+
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.test.context.DynamicPropertyRegistrar;
+import org.testcontainers.containers.MongoDBContainer;
+import org.testcontainers.utility.DockerImageName;
+
+@TestConfiguration(proxyBeanMethods = false)
+public class TestcontainersConfiguration {
+
+    @Bean
+    MongoDBContainer mongoDbContainer() {
+        return new MongoDBContainer(DockerImageName.parse("mongo:8"));
+    }
+
+    @Bean
+    DynamicPropertyRegistrar dynamicPropertyRegistrar(MongoDBContainer mongoDbContainer) {
+        return registry -> {
+            registry.add("spring.data.mongodb.uri", mongoDbContainer::getConnectionString);
+            registry.add("spring.data.mongodb.database", () -> "technical-content-management");
+        };
+    }
+
+}