使用Java springdata保存带有上限数组($ slice和$ sort)的mongoDB文档 [英] Saving with Java springdata a mongoDB document with capped array ($slice and $sort)

问题描述

我正在使用mongoDB和Java SpringData开发日志寄存器.

I'm developing a log register using mongoDB and Java SpringData.

这里用MongoDb限制的子集合讨论了mongoDB的结构，但是我会使用Java .最重要的是，我有一个包含一个或多个字段和一个上限数组的文档.

Here MongoDb capped sub-collection talks about mongoDB structure, but I would do with Java. The most important thing it's that I have a document with one or more fields and a capped array.

Java中是否有某种方法或方法可以做到这一点?

Is there some method or way in Java to do this?

我的对象就像:

user = {
   name: String,
   latest_messages: [String] (capped to a 100 elements)
}

在Java中:

public class MessageLog {
    private ObjectId id;
    private String name;
    private List<Message> messages;
}

位置:

public class Message{
    private String text;
    private String level;
    private Date date;
}

编辑:

我正在将Java与Spring源代码一起使用(mongodb驱动程序v2.10.1: http://central.maven.org/maven2/org/mongodb/mongo-java-driver/2.10.1/)

I'm using Java with Spring source (mongodb driver v2.10.1: http://central.maven.org/maven2/org/mongodb/mongo-java-driver/2.10.1/)

推荐答案

我终于使用以下代码获得了解决方案:

I finally get the solution using this code:

// Define the search query
BasicDBObject searchQuery = new BasicDBObject().append("idU", idUser);

// To create the json query to modify
BasicDBObject logDocument = new BasicDBObject();

// Create the object and add it to a list (because the $each require a list)
List<DBObject> list = new ArrayList<DBObject>();
DBObject object = new BasicDBObject().append("text", logMessage.getText());
object.append("level", logMessage.getLevel())
object.append("date", logMessage.getDate());
list.add(object);

// Create the $sort and $slice query at the same time
logDocument.append(
    "$push",
    new BasicDBObject().append("logs", new BasicDBObject().append("$each", list).append("$sort", new BasicDBObject().append("date", 1))
            .append("$slice", -10)));

String json = "{findAndModify:\"collectionLog\", query:" + searchQuery.toString() + ", update: " + logDocument.toString() + ", upsert:true}";

try {
     getMongoTemplate().executeCommand(json);
} catch (Exception e) {
     System.out.println(e);
}

我希望它对其他人有用！

I hope it will be useful to someone else!!!

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