其中find方法可以指定查询条件：
大于等于：$gte
小于等于：$lte
不等于：$ne
demo：users.find(new BasicDBObject("age", new BasicDBObject("$gte", 24)))
mongoDB2.6，java使用详解(三)
s.getSingletonInstance().obj2Json(value);
BasicDBObject obj = new BasicDBObject();
obj.put(MongodbManagerUtil.KEY, key);
obj.put(MongodbManagerUtil.VALUE, obj2Json);
BasicDBObject basicDBObject = new BasicDBObject(MongodbManagerUtil.KEY, key);
int size = cache.find(basicDBObject).count();
if (size==0) {
cache.save(obj);
}else{
cache.update(basicDBObject, obj);
}
}
/**
*
* get:(根据key从指定缓存对象中获取对象).
*
* @author sid
* @param cacheName
* @param key
* @return
*/
public T get(String cacheName, String key, Class classOfT) {
DBCollection cache = this.db.getCollection(cacheName);
List array = cache.find(new BasicDBObject(MongodbManagerUtil.KEY, key)).toArray();
if (array == null||array.size()==0) {
return null;
}
DBObject dbObject = array.get(0);
String json = (String)dbObject.get(MongodbManagerUtil.VALUE);
return JsonUtils.getSingletonInstance().formJson(json, classOfT);
}
/**
*
* remove:(从指定缓存对象中清除对象).
*
* @author sid
* @param cacheName
* @param key
*/
public void remove(String cacheName, String key) {
DBCollection cache = this.db.getCollection(cacheName);
cache.remove(new BasicDBObject(MongodbManagerUtil.KEY,key));
}
/**
*
* getKeys:(获取keys列表).
*
* @author sid
* @param cacheName
* @return
*/
public List getKeys(String cacheName){
List list = new ArrayList();
DBCollection cache = this.db.getCollection(cacheName);
DBCursor find = cache.find();
while (find.hasNext()) {
DBObject next = find.next();
String key = (String) next.get(MongodbManagerUtil.KEY);
list.add(key);
}
return list;
}
/**
*
* containsKey:(判断消息是否存在).
*
* @author sid
* @param cacheName
* @param key
* @return
*/
public Boolean containsKey(String cacheName,String key){
DBCollection cache = this.db.getCollection(cacheName);
BasicDBObject basicDBObject = new BasicDBObject(MongodbManagerUtil.KEY, key);
int size = cache.find(basicDBObject).count();
if (size==0) {
return false;
}else{
return true;
}
}
}
除了save、insert、update；mongodb还有remove等操作