How to call db.Collection.stats() from Mongo java driver using MongoClient class

问题

I am using this dependency.

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

Package:

package com.mongodb.MongoClient;

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

size
storageSize

Collection Status

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);

回答1:

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"));
}

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

来源：https://stackoverflow.com/questions/61052446/how-to-call-db-collection-stats-from-mongo-java-driver-using-mongoclient-class

标签

java

mongodb

mongo-java-driver