mongodb Java（八）

矫情吗；* 2021-12-21 06:55 207阅读 0赞

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package com.mongodb.text;
    
    import java.net.UnknownHostException;
    
    import com.mongodb.DB;
    import com.mongodb.DBCollection;
    import com.mongodb.DBCursor;
    import com.mongodb.DBObject;
    import com.mongodb.Mongo;
    import com.mongodb.MongoException;
    import com.mongodb.util.JSON;
    
    public class DataBase {
        public static void main(String[] args) 
            throws UnknownHostException, MongoException {
            //1.建立一个Mongo的数据库连接对象
            Mongo mg = new Mongo("127.0.0.1:27017");
            //查询所有的Database
            for (String name : mg.getDatabaseNames()) {
                System.out.println("dbName: " + name);
            }
            //2.创建相关数据库的连接
            DB db = mg.getDB("foobar");
            //查询数据库所有的集合
            for (String name : db.getCollectionNames()) {
                System.out.println("collectionName: " + name);
            }
            
            DBCollection users = db.getCollection("persons");
            //查询所有的数据
            DBCursor cur = users.find();
            while (cur.hasNext()) {
                DBObject object = cur.next();
                System.out.println(object.get("name"));
            }
            System.out.println(cur.count());
            System.out.println(cur.getCursorId());
            System.out.println(JSON.serialize(cur));
        }
    }

DataBase.java

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package com.mongodb.text;
    
    import java.net.UnknownHostException;
    import java.util.List;
    
    import org.bson.types.ObjectId;
    
    import com.mongodb.BasicDBObject;
    import com.mongodb.DB;
    import com.mongodb.DBCollection;
    import com.mongodb.DBCursor;
    import com.mongodb.DBObject;
    import com.mongodb.Mongo;
    import com.mongodb.MongoException;
    
    public class MongoDb {
        //1.建立一个Mongo的数据库连接对象
        static Mongo connection = null;
        //2.创建相关数据库的连接
        static DB db = null;
        public MongoDb(String dbName) throws UnknownHostException, MongoException{
            connection = new Mongo("127.0.0.1:27017");
            db = connection.getDB(dbName);
        }
        public static void main(String[] args) throws UnknownHostException, MongoException {
            //实例化
            MongoDb mongoDb = new MongoDb("foobar");
            /**
             * 1.创建一个名字叫javadb的数据库
             */
    //        mongoDb.createCollection("javadb");
            /**
             * 2.为集合javadb添加一条数据
             */
    //        DBObject dbs = new BasicDBObject();
    //        dbs.put("name", "uspcat.com");
    //        dbs.put("age", 2);
    //        List<String>  books = new ArrayList<String>();
    //        books.add("EXTJS");
    //        books.add("MONGODB");
    //        dbs.put("books", books);
    //        mongoDb.insert(dbs, "javadb");
            /**
             * 3.批量插入数据
             */
    //        List<DBObject> dbObjects = new ArrayList<DBObject>();
    //        DBObject jim = new BasicDBObject("name","jim");
    //        DBObject lisi = new BasicDBObject("name","lisi");
    //        dbObjects.add(jim);
    //        dbObjects.add(lisi);
    //        mongoDb.insertBatch(dbObjects, "javadb");
            /**
             * 4.根据ID删除数据
             */
    //        mongoDb.deleteById("502870dab9c368bf5b151a04", "javadb");
            /**
             * 5.根据条件删除数据
             */
    //        DBObject lisi = new BasicDBObject();
    //        lisi.put("name", "lisi");
    //        int count = mongoDb.deleteByDbs(lisi, "javadb");
    //        System.out.println("删除数据的条数是: "+count);
            /**
             * 6.更新操作,为集合增加email属性
             */
    //        DBObject update = new BasicDBObject();
    //        update.put("$set", 
    //                new BasicDBObject("eamil","uspcat@126.com"));
    //        mongoDb.update(new BasicDBObject(),
    //                update,false,true,"javadb");
            /**
             * 7.查询出persons集合中的name和age
             */
    //        DBObject keys = new BasicDBObject();
    //        keys.put("_id", false);
    //        keys.put("name", true);
    //        keys.put("age", true);
    //        DBCursor cursor = mongoDb.find(null, keys, "persons");
    //        while (cursor.hasNext()) {
    //            DBObject object = cursor.next();
    //            System.out.println(object.get("name"));
    //        }
            /**
             * 7.查询出年龄大于26岁并且英语成绩小于80分
             */
    //        DBObject ref = new BasicDBObject();
    //        ref.put("age", new BasicDBObject("$gte",26));
    //        ref.put("e", new BasicDBObject("$lte",80));
    //        DBCursor cursor = mongoDb.find(ref, null, "persons");
    //        while (cursor.hasNext()) {
    //            DBObject object = cursor.next();
    //            System.out.print(object.get("name")+"-->");
    //            System.out.print(object.get("age")+"-->");
    //            System.out.println(object.get("e"));
    //        }
            /**
             * 8.分页例子
             */
            DBCursor cursor = mongoDb.find(null, null, 0, 3, "persons");
            while (cursor.hasNext()) {
                DBObject object = cursor.next();
                System.out.print(object.get("name")+"-->");
                System.out.print(object.get("age")+"-->");
                System.out.println(object.get("e"));
            }        
            //关闭连接对象
            connection.close();
        }
        /**
         * 穿件一个数据库集合
         * @param collName 集合名称
         * @param db  数据库实例
         */
        public void createCollection(String collName){
            DBObject dbs = new BasicDBObject();
            db.createCollection("javadb", dbs);
        }
        /**
         * 为相应的集合添加数据
         * @param dbs
         * @param collName
         */
        public void insert(DBObject dbs,String collName){
            //1.得到集合
            DBCollection coll = db.getCollection(collName);
            //2.插入操作
            coll.insert(dbs);
        }
        /**
         * 为集合批量插入数据
         * @param dbses
         * @param collName
         */
        public void insertBatch(List<DBObject> dbses,String collName){
            //1.得到集合
            DBCollection coll = db.getCollection(collName);
            //2.插入操作
            coll.insert(dbses);
        }
        /**
         * 根据id删除数据
         * @param id
         * @param collName
         * @return 返回影响的数据条数
         */
        public int deleteById(String id,String collName){
            //1.得到集合
            DBCollection coll = db.getCollection(collName);
            DBObject dbs = new BasicDBObject("_id", new ObjectId(id));
            int count = coll.remove(dbs).getN();
            return count;
        }
        /**
         * 根据条件删除数据
         * @param id
         * @param collName
         * @return 返回影响的数据条数
         */    
        public int deleteByDbs(DBObject dbs,String collName){
            //1.得到集合
            DBCollection coll = db.getCollection(collName);
            int count = coll.remove(dbs).getN();
            return count;
        }
        /**
         * 更新数据
         * @param find 查询器
         * @param update 更新器
         * @param upsert 更新或插入
         * @param multi 是否批量更新
         * @param collName 集合名称
         * @return 返回影响的数据条数
         */
        public int update(DBObject find,
                            DBObject update,
                            boolean upsert,
                            boolean multi,
                            String collName){
            //1.得到集合
            DBCollection coll = db.getCollection(collName);
            int count = coll.update(find, update, upsert, multi).getN();
            return count;
        }
        /**
         * 查询器(分页)
         * @param ref
         * @param keys
         * @param start
         * @param limit
         * @return
         */
        public DBCursor find(DBObject ref, 
                DBObject keys,
                int start,
                int limit,
                String collName){
            DBCursor cur = find(ref, keys, collName);
            return cur.limit(limit).skip(start);
        }
        /**
         * 查询器(不分页)
         * @param ref
         * @param keys
         * @param start
         * @param limit
         * @param collName
         * @return
         */
        public DBCursor find(DBObject ref,
                DBObject keys,
                String collName){
            //1.得到集合
            DBCollection coll = db.getCollection(collName);
            DBCursor cur = coll.find(ref, keys);
            return cur;
        }    
    }

MongoDb.java

1、下载mongodb对Java的驱动

转载于:https://www.cnblogs.com/ecollab/p/7536511.html

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