mongodb QuickStart Demo
import com.mongodb.client.MongoClient; import com.mongodb.client.MongoClients; import com.mongodb.client.MongoCollection; import com.mongodb.client.MongoCursor; import com.mongodb.client.MongoDatabase; import com.mongodb.client.result.DeleteResult; import com.mongodb.client.result.UpdateResult; import org.bson.Document; import java.util.ArrayList; import java.util.List; import java.util.function.Consumer; import static com.mongodb.client.model.Accumulators.sum; import static com.mongodb.client.model.Aggregates.group; import static com.mongodb.client.model.Aggregates.match; import static com.mongodb.client.model.Aggregates.project; import static com.mongodb.client.model.Filters.and; import static com.mongodb.client.model.Filters.eq; import static com.mongodb.client.model.Filters.exists; import static com.mongodb.client.model.Filters.gt; import static com.mongodb.client.model.Filters.gte; import static com.mongodb.client.model.Filters.lt; import static com.mongodb.client.model.Filters.lte; import static com.mongodb.client.model.Projections.excludeId; import static com.mongodb.client.model.Sorts.descending; import static com.mongodb.client.model.Updates.inc; import static com.mongodb.client.model.Updates.set; import static java.util.Arrays.asList; import static java.util.Collections.singletonList; public class QuickTour { /** * Run this main method to see the output of this quick example. * * @param args takes an optional single argument for the connection string */ public static void main(final String[] args) throws Exception{ MongoClient mongoClient; if (args.length == 0) { // connect to the local database server mongoClient = MongoClients.create(); } else { mongoClient = MongoClients.create(args[0]); } // get handle to "mydb" database MongoDatabase database = mongoClient.getDatabase("mydb"); // get a handle to the "test" collection MongoCollection<Document> collection = database.getCollection("test"); // drop all the data in it collection.drop(); // make a document and insert it Document doc = new Document("name", "MongoDB") .append("type", "database") .append("count", 1) .append("info", new Document("x", 203).append("y", 102)); collection.insertOne(doc); // get it (since it's the only one in there since we dropped the rest earlier on) Document myDoc = collection.find().first(); System.out.println(myDoc.toJson()); // now, lets add lots of little documents to the collection so we can explore queries and cursors List<Document> documents = new ArrayList<Document>(); for (int i = 0; i < 100; i++) { documents.add(new Document("i", i)); } collection.insertMany(documents); System.out.println("total # of documents after inserting 100 small ones (should be 101) " + collection.countDocuments()); // find first myDoc = collection.find().first(); System.out.println(myDoc.toJson()); // lets get all the documents in the collection and print them out MongoCursor<Document> cursor = collection.find().iterator(); try { while (cursor.hasNext()) { System.out.println(cursor.next().toJson()); } } finally { cursor.close(); } for (Document cur : collection.find()) { System.out.println(cur.toJson()); } // now use a query to get 1 document out myDoc = collection.find(eq("i", 71)).first(); System.out.println(myDoc.toJson()); // now use a range query to get a larger subset cursor = collection.find(gt("i", 50)).iterator(); try { while (cursor.hasNext()) { System.out.println(cursor.next().toJson()); } } finally { cursor.close(); } // range query with multiple constraints cursor = collection.find(and(gt("i", 50), lte("i", 100))).iterator(); try { while (cursor.hasNext()) { System.out.println(cursor.next().toJson()); } } finally { cursor.close(); } // Query Filters myDoc = collection.find(eq("i", 71)).first(); System.out.println(myDoc.toJson()); // now use a range query to get a larger subset Consumer<Document> printBlock = new Consumer<Document>() { @Override public void accept(final Document document) { System.out.println(document.toJson()); } }; collection.find(gt("i", 50)).forEach(printBlock); // filter where; 50 < i <= 100 collection.find(and(gt("i", 50), lte("i", 100))).forEach(printBlock); // Sorting myDoc = collection.find(exists("i")).sort(descending("i")).first(); System.out.println(myDoc.toJson()); // Projection myDoc = collection.find().projection(excludeId()).first(); System.out.println(myDoc.toJson()); // Aggregation collection.aggregate(asList( match(gt("i", 0)), project(Document.parse("{ITimes10: {$multiply: ['$i', 10]}}"))) ).forEach(printBlock); myDoc = collection.aggregate(singletonList(group(null, sum("total", "$i")))).first(); System.out.println(myDoc.toJson()); // Update One collection.updateOne(eq("i", 10), set("i", 110)); // Update Many UpdateResult updateResult = collection.updateMany(lt("i", 100), inc("i", 100)); System.out.println(updateResult.getModifiedCount()); // Delete One collection.deleteOne(eq("i", 110)); // Delete Many DeleteResult deleteResult = collection.deleteMany(gte("i", 100)); System.out.println(deleteResult.getDeletedCount()); // Create Index collection.createIndex(new Document("i", 1)); // Clean up database.drop(); // release resources mongoClient.close(); } }