初始化連線：

String url = "xxx.xxx.xxx.xxx";
String dataName = "test";
int port = 27017;

MongoClient mongo = new MongoClient(url, port);
MongoDatabase db = mongo.getDatabase(dataName);
MongoCollection<BasicDBObject> collection1 = db.getCollection("collection1", BasicDBObject.class);

Insert：

BasicDBObject dbo = new
 
 BasicDBObject();
dbo.put("name", "jzp");
collection1.insertOne(dbo);

Delete：

BasicDBObject dbo = new BasicDBObject();
dbo.put("name", "jzp");
// 刪除符合條件的第一個文件
collection1.deleteOne(dbo);
// 刪除所有符合條件的文件
collection1.deleteMany(dbo);

Update：

//要更新的資料的主鍵條件
BasicDBObject dbo = new BasicDBObject();
dbo.put("name"
 
, "jzp");

//更新的目標資料條件
BasicDBObject update = new BasicDBObject();
update.put("name", "jzp1");
collection1.updateOne(update, new BasicDBObject("$set", update));

Find：

BasicDBObject dbo = new BasicDBObject();
dbo.put("name", "jzp");

BasicDBObject sort = new BasicDBObject();
sort.put("age", 1);
FindIterable<BasicDBObject> find = collection1.find(dbo).sort(sort).skip(0
 
).limit(10);
MongoCursor<BasicDBObject> iterator = find.iterator();
while (iterator.hasNext()) {
    BasicDBObject next = iterator.next();
    // TODO
}

Group by：

// where 條件
DBObject ageCond = new BasicDBObject();
ageCond.put("$gte", 1);
ageCond.put("$lte", 100);
DBObject where = new BasicDBObject();
where.put("age", ageCond);

// group by 計數器初始條件
BasicDBObject ini = new BasicDBObject();
ini.put("count", 0);

// group by mapReduce函式
StringBuffer reduce = new StringBuffer();
reduce.append(" function(doc,prev){  ");
reduce.append("     prev.count++;      ");
reduce.append(" }                    ");

BasicDBObject group = new BasicDBObject();
// group by 集合
group.put("ns", "collection1");
// group by 維度
group.put("key", new BasicDBObject("age", true));
// group by 計數器初始條件
group.put("initial", ini);
// group by mapReduce函式
group.put("$reduce", reduce.toString());
// group by where
group.put("cond", where);

// 執行group by
BasicDBObject command = new BasicDBObject();
command.put("group", group);
Document result = db.runCommand(command);
// retval 關鍵字
ArrayList<Document> dbList = (ArrayList) result.get("retval");
for (int i = 0; i < dbList.size(); i++) {
    Integer age = dbList.get(i).getInteger("age");
    long count = Math.round(dbList.get(i).getDouble("count"));
    // TODO
}

Lookup（對應mysql的left/right join）：

BasicDBObject lookupCon = new BasicDBObject();
lookupCon.put("from", "collection2");
lookupCon.put("localField", "name");
lookupCon.put("foreignField", "name");
lookupCon.put("as", "conn");
BasicDBObject lookup = new BasicDBObject();
lookup.put("$lookup", lookupCon);

BasicDBObject sortCon = new BasicDBObject();
sortCon.put("age", 1);
BasicDBObject sort = new BasicDBObject();
sort.put("$sort", sortCon);

BasicDBObject limit = new BasicDBObject();
limit.put("$limit", 10);

BasicDBObject skip = new BasicDBObject();
skip.put("$skip", 0);

List<BasicDBObject> list = new ArrayList<BasicDBObject>();
list.add(lookup);
list.add(sort);
list.add(skip);
list.add(limit);

AggregateIterable<BasicDBObject> it = collection1.aggregate(list);
MongoCursor<BasicDBObject> cursor = it.iterator();
while (cursor.hasNext()) {
    BasicDBObject dbo = cursor.next();
    // TODO
}