java mongodb query

To query MongoDB using Java, you can use the official Java driver provided by MongoDB. Here's an example of querying a collection named "users" for documents with a field "age" greater than 25:

// Create a MongoClient instance
MongoClient mongoClient = new MongoClient();

// Get a reference to the "test" database
MongoDatabase database = mongoClient.getDatabase("test");

// Get a reference to the "users" collection
MongoCollection<Document> collection = database.getCollection("users");

// Create a query to find documents with "age" greater than 25
Bson query = Filters.gt("age", 25);

// Find documents that match the query
FindIterable<Document> result = collection.find(query);

// Print the documents that match the query
for (Document document : result) {
    System.out.println(document.toJson());
}

// Close the MongoClient instance
mongoClient.close();

This example uses the `Filters.gt()` method to create a query that matches documents with a value for "age" greater than 25. The `find()` method returns a `FindIterable` object that can be iterated over to access the matching documents. Finally, the `toJson()` method is used to print the documents in JSON format.