mongo-java-driver -3.2.2学习笔记-01-MongoDB Driver Quick Tour

连接

// To directly connect to a single MongoDB server
// (this will not auto-discover the primary even if it's a member of a replica set)
MongoClient mongoClient = new MongoClient();

// or
MongoClient mongoClient = new MongoClient( "localhost" );

// or
MongoClient mongoClient = new MongoClient( "localhost" , 27017 );

// or, to connect to a replica set, with auto-discovery of the primary, supply a seed list of members
MongoClient mongoClient = new MongoClient(
Arrays.asList(new ServerAddress("localhost", 27017),
new ServerAddress("localhost", 27018),
new ServerAddress("localhost", 27019)));

// or use a connection string
MongoClientURI connectionString = new MongoClientURI("mongodb://localhost:27017,localhost:27018,localhost:27019");
MongoClient mongoClient = new MongoClient(connectionString);

MongoDatabase database = mongoClient.getDatabase("mydb");

MongoClient 代表一个mongo的数据库连接池，只需要一个单例进行操作

获得集合

MongoCollection<Document> collection = database.getCollection("test");

向集合中插入文档

Document doc = new Document("name", "MongoDB")
.append("type", "database")
.append("count", 1)
.append("info", new Document("x", 203).append("y", 102));
collection.insertOne(doc);

插入多条文档

List<Document> documents = new ArrayList<Document>();
for (int i = 0; i < 100; i++) {
documents.add(new Document("i", i));
}
collection.insertMany(documents);

查询

System.out.println(collection.count());//文档计数

Document myDoc = collection.find().first();
System.out.println(myDoc.toJson());//查询文档第一条记录

MongoCursor<Document> cursor = collection.find().iterator();
try {
while (cursor.hasNext()) {
System.out.println(cursor.next().toJson());
}
} finally {
cursor.close();
}//以游标的方式查询所有的文档

for (Document cur : collection.find()) {
System.out.println(cur.toJson());
}//查询文档

以过滤条件查询文档

import static com.mongodb.client.model.Filters.*;

myDoc = collection.find(eq("i", 71)).first();
System.out.println(myDoc.toJson());

查询一系列的文档，并且对于每个文档进行操作

// now use a range query to get a larger subset
Block<Document> printBlock = new Block<Document>() {
@Override
public void apply(final Document document) {
System.out.println(document.toJson());
}
};
collection.find(gt("i", 50)).forEach(printBlock);

对文档进行排序

myDoc = collection.find(exists("i")).sort(descending("i")).first();
System.out.println(myDoc.toJson());

排除查询到的某个文档

myDoc = collection.find().projection(excludeId()).first();
System.out.println(myDoc.toJson());

聚集查询

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());

更新文档s

collection.updateOne(eq("i", 10), set("i", 110));

UpdateResult updateResult = collection.updateMany(lt("i", 100), inc("i", 100));
System.out.println(updateResult.getModifiedCount());

删除文档s

collection.deleteOne(eq("i", 110));
DeleteResult deleteResult = collection.deleteMany(gte("i", 100));
System.out.println(deleteResult.getDeletedCount());

批量操作

// 2. Ordered bulk operation - order is guarenteed
collection.bulkWrite(
Arrays.asList(new InsertOneModel<>(new Document("_id", 4)),
new InsertOneModel<>(new Document("_id", 5)),
new InsertOneModel<>(new Document("_id", 6)),
new UpdateOneModel<>(new Document("_id", 1),
new Document("$set", new Document("x", 2))),
new DeleteOneModel<>(new Document("_id", 2)),
new ReplaceOneModel<>(new Document("_id", 3),
new Document("_id", 3).append("x", 4))));

// 2. Unordered bulk operation - no guarantee of order of operation
collection.bulkWrite(
Arrays.asList(new InsertOneModel<>(new Document("_id", 4)),
new InsertOneModel<>(new Document("_id", 5)),
new InsertOneModel<>(new Document("_id", 6)),
new UpdateOneModel<>(new Document("_id", 1),
new Document("$set", new Document("x", 2))),
new DeleteOneModel<>(new Document("_id", 2)),
new ReplaceOneModel<>(new Document("_id", 3),
new Document("_id", 3).append("x", 4))),
new BulkWriteOptions().ordered(false));