• 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();
        }
    }
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  • 原文地址:https://www.cnblogs.com/oktokeep/p/16337286.html
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