四、java对mongo数据库增删改查操作

系列导航

一、linux单机版mongo安装（带密码验证）

二、mongo集群搭建

三、java连接mongo数据库

四、java对mongo数据库增删改查操作

五、mongo备份篇 mongoexport、mongoimport 以及mongodump、mongorestore

数据库连接通用类参考：三、java连接mongo数据库

操作mongo的方法有很多种，如下是我比较习惯的写法，查询是最复杂的请大家参考。

一、mongo新增

    //把json当做数据内容插入mongo库中
    public int insertTrack(JSONObject jsonObject) {
        int result = 0;
        MongoDatabase database = MongoDbDao.getDb("testDb");
        MongoCollection picContent = database.getCollection("traceTable", BasicDBObject.class);
        DBObject dbObject = (DBObject) JSON.parse(jsonObject.toString());
        picContent.insertOne(dbObject);
     return result;
    }

 //批量添加
   public int insertMany( ) {
        int result = 0;
        MongoDatabase database = MongoDbDao.getDb("testDb");
        MongoCollection picContent = database.getCollection("traceTable", BasicDBObject.class);
        String a ="{ \"_id\" : \"1\" , \"machineMac\" : \"FC83C6\"}";
        String b = "{ \"_id\" : \"2\" , \"machineMac\" : \"F1727E\"}";
        DBObject dbObjectA = (DBObject) JSON.parse(a);
        DBObject dbObjectB = (DBObject) JSON.parse(a);

        ArrayList mongoList = new ArrayList();
        mongoList.add(dbObjectA);
        mongoList.add(dbObjectB);

        picContent.insertMany(mongoList);
        mongoList.clear();

     return result;
    }

二、mongo删除

    public int removeTrack(String trackId) {
        int result = 0;
        MongoDatabase database = MongoDbDao.getDb("testDb");
        MongoCollection picContent = database.getCollection("traceTable", BasicDBObject.class);
        //如下注意一般mongo自带的主键如右边 "_id" : ObjectId("60703e8f7b85766cd2554cf9")  字符串外层会带一个ObjectId()操作_id的时候使用new ObjectId()就可以
        BasicDBObject delSql = new BasicDBObject("_id",  new ObjectId(trackId));
        picContent.findOneAndDelete(delSql);
        return result;
    }

三、mongo更新

    public void updateTrack() {
        MongoDatabase database = MongoDbDao.getDb("etc_data");
        MongoCollection picContent = database.getCollection("new_trace", BasicDBObject.class);
        BasicDBObject whereSql = new BasicDBObject("_id", new ObjectId("6124b4c72b2ea593ccdd3e60"));
        BasicDBObject updateNewOneSql = new BasicDBObject("$set", new BasicDBObject("address", "11111"));
        picContent.updateOne(whereSql,updateNewOneSql) ;
    }

四、mongo查询

   //综合的查询方法包括如何设置查询条件、返回的数据项、排序规则，返回的数据条数
    private void selectTrack() {

        MongoDatabase database = MongoDbDao.getDb("testDb");
        //ReadPreference.secondaryPreferred() 意思为在集群模式下查寻从库，
        MongoCollection<BasicDBObject> collection = database.getCollection("oiltrack", BasicDBObject.class).withReadPreference(ReadPreference.secondaryPreferred());

        String trackId = "123";
        String idNum = "123456";
        Timestamp createDateTime = getTimestamp();

        //设置查询条件
        BasicDBObject idCondObj = null;
        BasicDBList idBasicDBList = new BasicDBList();

        idBasicDBList.add(new BasicDBObject("idNum", idNum)); //相等条件
        idBasicDBList.add(new BasicDBObject("trackId", new BasicDBObject("$ne", trackId)));//不相等条件
        idBasicDBList.add(new BasicDBObject("createDateTime", new BasicDBObject("$gt", new Date(createDateTime.getTime() - 24 * 60 * 60 * 1000))));//时间大于使用
        idBasicDBList.add(new BasicDBObject("createDateTime", new BasicDBObject("$lt", new Date(createDateTime.getTime()))));//时间小于使用
        idCondObj = new BasicDBObject().append(QueryOperators.AND, idBasicDBList); //查询条件

        //设置返回字段列表
        BasicDBObject selectObj = new BasicDBObject("colum1", 1).append("colum2", 1).append("colum3", 1);
        //设置排序字段
        BasicDBObject sortObj = new BasicDBObject();
        sortObj.put("dateTime", 1);

        List<String> trackBeanTrackIdList = new ArrayList<String>();

        ArrayList<BasicDBObject> idRetList = new ArrayList<BasicDBObject>();
        //limit(10)只查询前十条，不需要可以去掉
        collection.find(idCondObj).projection(selectObj).sort(sortObj).limit(10).into(idRetList);

        for (BasicDBObject tempValue : idRetList) {
            System.out.println(tempValue.getString("colum1"));
            System.out.println(tempValue.getString("colum2"));
        }
    }    

    //查询mongo记录中某属性字段不存在的记录
    private void selectExistsTrack() {

        MongoDatabase database = MongoDbDao.getDb("testDb");
        //ReadPreference.secondaryPreferred() 意思为在集群模式下查寻从库，
        MongoCollection<BasicDBObject> collection = database.getCollection("oiltrack", BasicDBObject.class).withReadPreference(ReadPreference.secondaryPreferred());

        //需要查询的字段
        Map valueMap = new HashMap();
        valueMap.put("_id", 1);
        valueMap.put("name", 1);

        BasicDBObject whereObj = new BasicDBObject();
        //查询记录中没有date这个属性的记录
        whereObj.put("date", new BasicDBObject("$exists", false));

        //batchSize(100)很重要，如果数据量特别大不加这个执行中会报错，batchSize(100)意思是每次取出100条数据，循环结束再取100条
        Iterator iterator = collection.find(whereObj).batchSize(100).projection(new BasicDBObject(valueMap)).iterator();
        while (iterator.hasNext()) {
            BasicDBObject obj = (BasicDBObject) iterator.next();
            String _id = obj.getString("_id");
            System.out.println("_id:" + _id);
        }
    }

    //获取当前时间
    public Timestamp getTimestamp() {
        Date currentTime = new Date();
        SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String dateString = formatter.format(currentTime);
        Timestamp timestamp = Timestamp.valueOf(dateString);
        return timestamp;
    }