MongoDB Java 通用方法
030472875ken
13年前
最近写了一个针对MongoDB的一些常用操作的公共类，希望对初学者有帮助。 <br /> <pre class="brush:java; toolbar: true; auto-links: false;">package model.dao; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import org.apache.log4j.Logger; 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; /** * MongoDB Manager * @author Ken Chau * */ public class MongoDBManager { private static Logger log = Logger.getLogger(MongoDBManager.class); private static Mongo mg = null; private static DB db = null; private final static MongoDBManager instance = new MongoDBManager(); /** * 实例化 * @return * @throws Exception */ public static MongoDBManager getInstance() throws Exception { return instance; } static { try { mg = new Mongo(HOST, PORT); db=mg.getDB(DB); } catch (Exception e) { log.error("Can't connect MongoDB!"); e.printStackTrace(); } } /** * 获取集合（表） * @param collection */ public static DBCollection getCollection(String collection) { return db.getCollection(collection); } /** * ----------------------------------分割线-------------------------------------- */ /** * 插入 * @param collection * @param map */ public void insert(String collection , Map<String, Object> map) { try { DBObject dbObject = map2Obj(map); getCollection(collection).insert(dbObject); } catch (MongoException e) { log.error("MongoException:" + e.getMessage()); } } /** * 批量插入 * @param collection * @param list */ public void insertBatch(String collection ,List<Map<String, Object>> list) { if (list == null || list.isEmpty()) { return; } try { List<DBObject> listDB = new ArrayList<DBObject>(); for (int i = 0; i < list.size(); i++) { DBObject dbObject = map2Obj(list.get(i)); listDB.add(dbObject); } getCollection(collection).insert(listDB); } catch (MongoException e) { log.error("MongoException:" + e.getMessage()); } } /** * 删除 * @param collection * @param map */ public void delete(String collection ,Map<String, Object> map) { DBObject obj = map2Obj(map); getCollection(collection).remove(obj); } /** * 删除全部 * @param collection * @param map */ public void deleteAll(String collection) { List<DBObject> rs = findAll(collection); if (rs != null && !rs.isEmpty()) { for (int i = 0; i < rs.size(); i++) { getCollection(collection).remove(rs.get(i)); } } } /** * 批量删除 * @param collection * @param list */ public void deleteBatch(String collection,List<Map<String, Object>> list) { if (list == null || list.isEmpty()) { return; } for (int i = 0; i < list.size(); i++) { getCollection(collection).remove(map2Obj(list.get(i))); } } /** * 计算满足条件条数 * @param collection * @param map */ public long getCount(String collection,Map<String, Object> map) { return getCollection(collection).getCount(map2Obj(map)); } /** * 计算集合总条数 * @param collection * @param map */ public long getCount(String collection) { return getCollection(collection).find().count(); } /** * 更新 * @param collection * @param setFields * @param whereFields */ public void update(String collection,Map<String, Object> setFields, Map<String, Object> whereFields) { DBObject obj1 = map2Obj(setFields); DBObject obj2 = map2Obj(whereFields); getCollection(collection).updateMulti(obj1, obj2); } /** * 查找对象（根据主键_id） * @param collection * @param _id */ public DBObject findById(String collection,String _id) { DBObject obj = new BasicDBObject(); obj.put("_id", ObjectId.massageToObjectId(_id)); return getCollection(collection).findOne(obj); } /** * 查找集合所有对象 * @param collection */ public List<DBObject> findAll(String collection) { return getCollection(collection).find().toArray(); } /** * 查找（返回一个对象） * @param map * @param collection */ public DBObject findOne(String collection,Map<String, Object> map) { DBCollection coll = getCollection(collection); return coll.findOne(map2Obj(map)); } /** * 查找（返回一个List<DBObject>） * @param <DBObject> * @param map * @param collection * @throws Exception */ public List<DBObject> find(String collection,Map<String, Object> map) throws Exception { DBCollection coll = getCollection(collection); DBCursor c = coll.find(map2Obj(map)); if (c != null) return c.toArray(); else return null; }</pre> <br />