bael-5848 - How to Insert a HashMap Into MongoDB With Java (#12938)

* bael-5848 - new module

* bael-5848 - tests

persistence-modules/pom.xml

@@ -64,6 +64,7 @@
         <module>spring-boot-persistence-h2</module>
         <module>spring-boot-persistence-mongodb</module>
         <module>spring-boot-persistence-mongodb-2</module>
+        <module>spring-boot-persistence-mongodb-3</module>
         <module>spring-data-arangodb</module>
         <module>spring-data-cassandra</module>
         <module>spring-data-cassandra-test</module>

persistence-modules/spring-boot-persistence-mongodb-2/README.md

@@ -7,4 +7,4 @@
 - [Count Documents Using Spring Data MongoDB Repository](https://www.baeldung.com/spring-data-mongodb-count)
 - [Spring Data MongoDB – Configure Connection](https://www.baeldung.com/spring-data-mongodb-connection)
 - [Connect to Multiple Databases Using Spring Data MongoDB](https://www.baeldung.com/mongodb-multiple-databases-spring-data)
-- More articles: [[<--prev]](../spring-boot-persistence-mongodb)
+- More articles: [[<--prev]](../spring-boot-persistence-mongodb) [[next-->]](../spring-boot-persistence-mongodb-3)

persistence-modules/spring-boot-persistence-mongodb-3/README.md

@@ -0,0 +1,3 @@
+# Relevant Articles
+
+- More articles: [[<--prev]](../spring-boot-persistence-mongodb-2)

persistence-modules/spring-boot-persistence-mongodb-3/pom.xml

@@ -0,0 +1,34 @@
+<?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>
+    <artifactId>spring-boot-persistence-mongodb-3</artifactId>
+    <name>spring-boot-persistence-mongodb-3</name>
+    <packaging>war</packaging>
+    <description>This is simple boot application for Spring boot persistence mongodb</description>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-2</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-boot-2</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-data-mongodb</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>de.flapdoodle.embed</groupId>
+            <artifactId>de.flapdoodle.embed.mongo</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+</project>

persistence-modules/spring-boot-persistence-mongodb-3/src/main/java/com/baeldung/boot/hashmap/SpringBootHashMapApplication.java

@@ -0,0 +1,12 @@
+package com.baeldung.boot.hashmap;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpringBootHashMapApplication {
+
+    public static void main(String... args) {
+        SpringApplication.run(SpringBootHashMapApplication.class, args);
+    }
+}

persistence-modules/spring-boot-persistence-mongodb-3/src/main/resources/application.properties

@@ -0,0 +1 @@
+spring.application.name=spring-boot-persistence-mongodb-3

persistence-modules/spring-boot-persistence-mongodb-3/src/test/java/com/baeldung/boot/hashmap/MongoDbHashMapIntegrationTest.java

@@ -0,0 +1,120 @@
+package com.baeldung.boot.hashmap;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import org.bson.Document;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.data.mongodb.core.MongoTemplate;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.TestPropertySource;
+
+import com.mongodb.BasicDBObject;
+
+@SpringBootTest
+@DirtiesContext
+@TestPropertySource("/embedded.properties")
+class MongoDbHashMapIntegrationTest {
+
+    private static final Map<String, Object> MAP = new HashMap<>();
+    private static final Set<Map<String, Object>> MAP_SET = new HashSet<>();
+
+    @Autowired
+    private MongoTemplate mongo;
+
+    private void assertHasMongoId(Map<String, Object> saved) {
+        assertNotNull(saved);
+        assertNotNull(saved.get("_id"));
+    }
+
+    @BeforeAll
+    static void init() {
+        MAP.put("name", "Document A");
+        MAP.put("number", 2);
+        MAP.put("dynamic", true);
+
+        Map<String, Object> otherMap = new HashMap<>();
+        otherMap.put("name", "Other Document");
+        otherMap.put("number", 22);
+
+        MAP_SET.add(MAP);
+        MAP_SET.add(otherMap);
+    }
+
+    @Test
+    void whenUsingMap_thenInsertSucceeds() {
+        Map<String, Object> saved = mongo.insert(MAP, "map-collection");
+
+        assertHasMongoId(saved);
+    }
+
+    @Test
+    void whenMapSet_thenInsertSucceeds() {
+        Collection<Map<String, Object>> saved = mongo.insert(MAP_SET, "map-set");
+
+        saved.forEach(this::assertHasMongoId);
+        assertEquals(2, saved.size());
+    }
+
+    @Test
+    void givenMap_whenDocumentConstructed_thenInsertSucceeds() {
+        Document document = new Document(MAP);
+
+        Document saved = mongo.insert(document, "doc-collection");
+
+        assertHasMongoId(saved);
+    }
+
+    @Test
+    void givenMap_whenBasicDbObjectConstructed_thenInsertSucceeds() {
+        BasicDBObject dbObject = new BasicDBObject(MAP);
+
+        BasicDBObject saved = mongo.insert(dbObject, "db-collection");
+
+        assertHasMongoId(saved);
+    }
+
+    @Test
+    void givenObjectList_whenDocumentSetConstructed_thenInsertSucceeds() {
+        Map<String, List<Object>> input = new HashMap<>();
+        List<Object> listOne = new ArrayList<>();
+        listOne.add("Doc A");
+        listOne.add(1);
+
+        List<Object> listTwo = new ArrayList<>();
+        listTwo.add("Doc B");
+        listTwo.add(2);
+
+        input.put("a", listOne);
+        input.put("b", listTwo);
+
+        Set<Document> docs = input.entrySet()
+            .stream()
+            .collect(HashSet<Document>::new, (set, entry) -> {
+                Document document = new Document();
+
+                document.put("_id", entry.getKey());
+                Iterator<Object> iterator = entry.getValue()
+                    .iterator();
+                document.put("name", iterator.next());
+                document.put("number", iterator.next());
+
+                set.add(document);
+            }, Set::addAll);
+
+        Collection<Document> saved = mongo.insert(docs, "custom-set");
+        saved.forEach(this::assertHasMongoId);
+    }
+}

persistence-modules/spring-boot-persistence-mongodb-3/src/test/resources/embedded.properties

@@ -0,0 +1 @@
+spring.mongodb.embedded.version=4.4.9

persistence-modules/spring-boot-persistence-mongodb-3/src/test/resources/logback-test.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration scan="true" scanPeriod="15 seconds" debug="false">
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>[%d{ISO8601}]-[%thread] %-5level %logger - %msg%n</pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>