如何使用MongoClient类从Mongo Java驱动程序调用db.Collection.stats() [英] How to call db.Collection.stats() from Mongo java driver using MongoClient class

问题描述

我正在使用这种依赖关系.

I am using this dependency.

        <dependency>
            <groupId>org.mongodb</groupId>
            <artifactId>mongodb-driver</artifactId>
            <version>3.12.2</version>
        </dependency>

包装:

打包com.mongodb.MongoClient;

如何按名称获取收藏集，然后获取其状态，以便可以使用以下信息:

How can I get collection by name then get its status so that the following information will be available:

1. 大小
2. storageSize

收藏状态

看来，此的答案从Mongo Java驱动程序调用db.Collection.stats()使用已弃用的类 package com.mongodb;

It seems that the answer for this How to call db.Collection.stats() from Mongo java driver uses deprecated class package com.mongodb;

        // Mongodb initialization parameters.
        int port_no = 27017;
        String auth_user="jcg", auth_pwd = "admin@123", host_name = "localhost", db_name = "mongoauthdemo", db_col_name = "emp", encoded_pwd = "";

        /* Imp. Note -
         *      1.  Developers will need to encode the 'auth_user' or the 'auth_pwd' string if it contains the <code>:</code> or the <code>@</code> symbol. If not, the code will throw the <code>java.lang.IllegalArgumentException</code>.
         *      2.  If the 'auth_user' or the 'auth_pwd' string does not contain the <code>:</code> or the <code>@</code> symbol, we can skip the encoding step.
         */
        try {
            encoded_pwd = URLEncoder.encode(auth_pwd, "UTF-8");
        } catch (UnsupportedEncodingException ex) {
            log.error(ex);
        }

        // Mongodb connection string.
        String client_url = "mongodb://" + auth_user + ":" + encoded_pwd + "@" + host_name + ":" + port_no + "/" + db_name;
        MongoClientURI uri = new MongoClientURI(client_url);

        // Connecting to the mongodb server using the given client uri.
        MongoClient mongo_client = new MongoClient(uri);

        // Fetching the database from the mongodb.
        MongoDatabase db = mongo_client.getDatabase(db_name);

        // Fetching the collection from the mongodb.
        MongoCollection<Document> coll = db.getCollection(db_col_name);

推荐答案

这使用的是MongoDB Java驱动程序版本3.12:

This is using the MongoDB Java driver version 3.12:

try(MongoClient mongoClient = MongoClients.create("mongodb://localhost:27017/")) {

    MongoDatabase db = mongoClient.getDatabase("test");
    Document collStatsResults = db.runCommand(new Document("collStats", "myCollection"));
    System.out.println(collStatsResults.get("size"));
    System.out.println(collStatsResults.get("storageSize"));
}

请注意try-with-resources子句的用法；在使用MongoClient对象释放与连接相关的资源后，它将关闭.

Note the usage of the try-with-resources clause; it closes the MongoClient object after its use to release the connection related resources.

这篇关于如何使用MongoClient类从Mongo Java驱动程序调用db.Collection.stats()的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！