BAEL-5368 Guide to Find in MongoDB (#12361)

* BAEL-5368 | Article code

* BAEL-5368 | Package renamed

persistence-modules/java-mongodb-3/src/main/java/com/baeldung/mongo/find/FindOperation.java

@@ -0,0 +1,86 @@
+package com.baeldung.mongo.find;
+
+import com.mongodb.MongoClient;
+import com.mongodb.client.FindIterable;
+import com.mongodb.client.MongoCollection;
+import com.mongodb.client.MongoCursor;
+import com.mongodb.client.MongoDatabase;
+import org.bson.Document;
+import org.bson.conversions.Bson;
+
+import static com.mongodb.client.model.Filters.eq;
+import static com.mongodb.client.model.Projections.fields;
+import static com.mongodb.client.model.Projections.include;
+
+public class FindOperation {
+
+    private static MongoClient mongoClient;
+    private static MongoDatabase database;
+    private static MongoCollection<Document> collection;
+    private static String collectionName;
+    private static String databaseName;
+
+    public static void setUp() {
+        if (mongoClient == null) {
+            mongoClient = new MongoClient("localhost", 27017);
+
+            databaseName = "baeldung";
+            collectionName = "employee";
+
+            database = mongoClient.getDatabase(databaseName);
+            collection = database.getCollection(collectionName);
+        }
+    }
+
+    public static void retrieveAllDocumentsUsingFind() {
+        FindIterable<Document> documents = collection.find();
+
+        MongoCursor<Document> cursor = documents.iterator();
+        while (cursor.hasNext()) {
+            System.out.println(cursor.next());
+        }
+    }
+
+    public static void retrieveAllDocumentsUsingFindWithQueryFilter() {
+        Bson filter = eq("department", "Engineering");
+        FindIterable<Document> documents = collection.find(filter);
+
+        MongoCursor<Document> cursor = documents.iterator();
+        while (cursor.hasNext()) {
+            System.out.println(cursor.next());
+        }
+    }
+
+    public static void retrieveAllDocumentsUsingFindWithQueryFilterAndProjection() {
+        Bson filter = eq("department", "Engineering");
+        Bson projection = fields(include("name", "age"));
+        FindIterable<Document> documents = collection.find(filter)
+          .projection(projection);
+
+        MongoCursor<Document> cursor = documents.iterator();
+        while (cursor.hasNext()) {
+            System.out.println(cursor.next());
+        }
+    }
+
+    public static void retrieveFirstDocument() {
+        FindIterable<Document> documents = collection.find();
+        Document document = documents.first();
+
+        System.out.println(document);
+    }
+
+    public static void main(String args[]) {
+
+        setUp();
+
+        retrieveAllDocumentsUsingFind();
+
+        retrieveAllDocumentsUsingFindWithQueryFilter();
+
+        retrieveAllDocumentsUsingFindWithQueryFilterAndProjection();
+
+        retrieveFirstDocument();
+    }
+}
+

persistence-modules/java-mongodb-3/src/main/resources/logback.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<configuration>
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n
+            </pattern>
+        </encoder>
+    </appender>
+
+    <root level="INFO">
+        <appender-ref ref="STDOUT" />
+    </root>
+</configuration>