java學習(三) java 中 mongodb的各種操作

一. 常用查詢:

1. 查詢一條數據:(多用於保存時判斷db中是否已有當前數據,這里 is  精確匹配,模糊匹配 使用 regex...)

public PageUrl getByUrl(String url) {
        return findOne(new Query(Criteria.where("url").is(url)),PageUrl.class);
    }

2. 查詢多條數據:linkUrl.id 屬於分級查詢

public List<PageUrl> getPageUrlsByUrl(int begin, int end,String linkUrlid) {        
        Query query = new Query();
        query.addCriteria(Criteria.where("linkUrl.id").is(linkUrlid));
        return find(query.limit(end - begin).skip(begin), PageUrl.class);        
    }

3. 模糊查詢:

public long getProcessLandLogsCount(List<Condition> conditions)
    {
        Query query = new Query();
        if (conditions != null && conditions.size() > 0) {
            for (Condition condition : conditions) {
                query.addCriteria(Criteria.where(condition.getKey()).regex(".*?\\" +condition.getValue().toString()+ ".*"));
            }
        }
        return count(query, ProcessLandLog.class);
    }

4. gte: 大於等於,lte小於等於...注意查詢的時候各個字段的類型要和mongodb中數據類型一致

public List<ProcessLandLog> getProcessLandLogs(int begin,int end,List<Condition> conditions,String orderField,Direction direction)
    {
        Query query = new Query();
        if (conditions != null && conditions.size() > 0) {
            for (Condition condition : conditions) {
                if(condition.getKey().equals("time")){
                    query.addCriteria(Criteria.where("time").gte(condition.getValue())); //gte: 大於等於
                }else if(condition.getKey().equals("insertTime")){
                    query.addCriteria(Criteria.where("insertTime").gte(condition.getValue()));
                }else{
                    query.addCriteria(Criteria.where(condition.getKey()).is(condition.getValue()));
                }
            }
        }
        return find(query.limit(end - begin).skip(begin).with(new Sort(new Sort.Order(direction, orderField))), ProcessLandLog.class);
    }

public List<DpsLand> getDpsLandsByTime(int begin, int end, Date beginDate,Date endDate) {
  return find(new Query(Criteria.where("updateTime").gte(beginDate).lte(endDate)).limit(end - begin).skip(begin),
    DpsLand.class);
 }

    查詢字段不存在的數據

public List<GoodsDetail> getGoodsDetails2(int begin, int end) {
        Query query = new Query();
        query.addCriteria(Criteria.where("goodsSummary").not());
        return find(query.limit(end - begin).skip(begin),GoodsDetail.class);
    }

 

 

5. 查詢數量:

public long getPageInfosCount(List<Condition> conditions) {
        Query query = new Query();
        if (conditions != null && conditions.size() > 0) {
            for (Condition condition : conditions) {
                query.addCriteria(Criteria.where(condition.getKey()).is(condition.getValue()));
            }
        }
        return count(query, PageInfo.class);
    }

6. 更新一條數據的一個字段:

public WriteResult updateTime(PageUrl pageUrl) { String id = pageUrl.getId(); return updateFirst(new Query(Criteria.where("id").is(id)),Update.update("updateTime", pageUrl.getUpdateTime()), PageUrl.class); }

7. 更新一條數據的多個字段:

//調用更新 private void updateProcessLandLog(ProcessLandLog processLandLog, int crawlResult) { List<String> fields = new ArrayList<String>(); List<Object> values = new ArrayList<Object>(); fields.add("state"); fields.add("result"); fields.add("time"); values.add("1"); values.add(crawlResult); values.add(Calendar.getInstance().getTime()); processLandLogReposity.updateProcessLandLog(processLandLog, fields, values); } //更新 public void updateProcessLandLog(ProcessLandLog land, List<String> fields,List<Object> values) { Update update = new Update(); int size = fields.size(); for(int i = 0 ; i < size; i++){ String field = fields.get(i); Object value = values.get(i); update.set(field, value); } updateFirst(new Query(Criteria.where("id").is(land.getId())), update,ProcessLandLog.class); }

8. 刪除數據:

public void deleteObject(Class<T> clazz,String id) {
        remove(new Query(Criteria.where("id").is(id)),clazz);
    }

9.保存數據:

//插入一條數據
public void saveObject(Object obj) {
        insert(obj);
    }

//插入多條數據    
public void saveObjects(List<T> objects) {
        for(T t:objects){
            insert(t);
        }
    }