• Java连接MongoDB样例


    package com.moonlit.example;
    
    import com.mongodb.BasicDBObject;
    import com.mongodb.BulkWriteOperation;
    import com.mongodb.BulkWriteResult;
    import com.mongodb.DB;
    import com.mongodb.DBCollection;
    import com.mongodb.DBCursor;
    import com.mongodb.DBObject;
    import com.mongodb.MongoClient;
    
    public class MongodbTest {
        public static void main(String[] args) {
            MongoClient mongoClient = new MongoClient();
            DB db = mongoClient.getDB("mydb");
            DBCollection coll = db.getCollection("testCollection");
            
            // insert a document
            BasicDBObject doc = new BasicDBObject("name", "MongoDB")
                    .append("type", "database")
                    .append("count", 1)
                    .append("info", new BasicDBObject("x", 123).append("y", 456));
            coll.insert(doc);
            
            // find the first document in a collection
            DBObject myDoc = coll.findOne();
            System.out.println(myDoc);
            
            // adding multiple documents
            for (int i = 1; i <= 100; i ++) {
                coll.insert(new BasicDBObject("i", i));
            }
            
            // counting documents in a collection
            System.out.println(coll.getCount());
            
            // using a cursor to get all collection
            DBCursor cursor = coll.find();
            try {
                while (cursor.hasNext())
                    System.out.println(cursor.next());
            } finally {
                cursor.close();
            }
            
            // get a single document with a guery
            BasicDBObject query = new BasicDBObject("i", 23);
            cursor = coll.find(query);
            try {
                while (cursor.hasNext()) 
                    System.out.println(cursor.next());
            } finally {
                cursor.close();
            }
            
            query = new BasicDBObject("j", new BasicDBObject("$ne", 93))
                    .append("i", new BasicDBObject("$gt", 90));
            cursor = coll.find(query);
            try {
                while (cursor.hasNext())
                    System.out.println(cursor.next());
            } finally {
                cursor.close();
            }
            
            query = new BasicDBObject("i", new BasicDBObject("$ne", 93).append("$gt", 90));
            
            cursor = coll.find(query);
            try {
                while (cursor.hasNext())
                    System.out.println(cursor.next());
            } finally {
                cursor.close();
            }
    
    //        // delete all 
    //        cursor = coll.find();
    //        try {
    //            while (cursor.hasNext())
    //                coll.remove(cursor.next());
    //        } finally {
    //            cursor.close();
    //        }
    //        
    //        // count
    //        System.out.println(coll.getCount());
            
    //        BulkWriteOperation builder = coll.initializeOrderedBulkOperation();
    //        builder.insert(new BasicDBObject("_id", 1));
    //        builder.insert(new BasicDBObject("_id", 2));
    //        builder.insert(new BasicDBObject("_id", 3));
            
    //        builder.find(new BasicDBObject("_id", 1)).updateOne(new BasicDBObject("$set", new BasicDBObject("x", 123)));
    //        builder.find(new BasicDBObject("_id", 2)).remove();
    //        builder.find(new BasicDBObject("_id", 3)).replaceOne(new BasicDBObject("_id", 3).append("x", 4));
            
    //        BulkWriteResult result = builder.execute();
            
            
        }
    }
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  • 原文地址:https://www.cnblogs.com/moonlightpoet/p/5625073.html
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