/** * 数据库接口 * @author [email protected] * @version 2011-9-27 */ public interface MongoService { /** * 通过gridFS上传对象 * @param obj 目标对象 * @param paramsMap 参数map * @return * @throws Exception */ public boolean gridFSUpload(Object obj, HashMap<String, Object> paramsMap) throws Exception; /** * 通过gridFS删除 * @param paramsMap 参数map * @return */ public boolean gridFSDelete(HashMap<String, Object> paramsMap); /** * 插入DBObject对象 * @param idName 该对象的Id名称 * @param dbObject 该对象 * @return */ public DBObject insert(String idName, DBObject dbObject); /** * 获取对象 * @param dbObject * @return */ public DBObject getByObj(DBObject dbObject); /** * 更新数据 * @param query 该数据的对象 * @param obj 更新的数据 * @return */ public Boolean update(DBObject query,DBObject obj); /** * 删除对象 * @param obj */ public void remove(DBObject obj); }
public class MongoServiceImpl implements MongoService {
private String bucketName;
private DB db;
public MongoServiceImpl(String dbName, String bucketName) {
this.bucketName = bucketName;
Mongo mongo;
try {
mongo = new Mongo("192.168.17.28", 27017);
this.db = mongo.getDB(dbName);
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (MongoException e) {
e.printStackTrace();
}
}
/**
* 通过gridFS上传对象
* @param obj 目标对象
* @param paramsMap 参数map
* @return
* @throws Exception
*/
@Override
public synchronized boolean gridFSUpload(Object obj, HashMap<String, Object> paramsMap)
throws IOException {
boolean flag = false;
GridFS gridFS = new GridFS(db, bucketName);
GridFSFile gridFSFile = null;
if (obj instanceof InputStream) {
gridFSFile = gridFS.createFile((InputStream) obj);
} else if (obj instanceof byte[]) {
gridFSFile = gridFS.createFile((byte[]) obj);
} else if (obj instanceof File) {
gridFSFile = gridFS.createFile((File) obj);
}
if (gridFSFile != null && paramsMap != null) {
Iterator iter = paramsMap.entrySet().iterator();
while (iter.hasNext()) {
Map.Entry<String, Object> entry = (Entry<String, Object>) iter.next();
gridFSFile.put(entry.getKey(), entry.getValue());
}
gridFSFile.save();
flag = true;
}
return flag;
}
/**
* 通过gridFS删除
* @param paramsMap 参数map
* @return
*/
@Override
public synchronized boolean gridFSDelete(HashMap<String, Object> paramsMap) {
boolean flag = false;
GridFS gridFS = new GridFS(db, bucketName);
DBObject query = new BasicDBObject();
if (paramsMap != null) {
Iterator iter = paramsMap.entrySet().iterator();
while (iter.hasNext()) {
Map.Entry<String, Object> entry = (Entry<String, Object>) iter.next();
query.put(entry.getKey(), entry.getValue());
}
}
DBObject obj = gridFS.findOne(query);
if(obj != null){
gridFS.remove(obj);
flag = true;
}
return flag;
}
/**
* 插入DBObject对象
* @param idName 该对象的Id名称
* @param dbObject 该对象
* @return
*/
@Override
public synchronized DBObject insert(String idName, DBObject dbObject) {
Integer id = getAutoIncreaseID(idName);
dbObject.put(idName, id);
getCollection().insert(dbObject);
return dbObject;
}
/**
* 获取连接
* @return
*/
public DBCollection getCollection() {
return db.getCollection(this.bucketName);
}
/**
* 根据表名获取连接
* @param name
* @return
*/
public DBCollection getCollection(String name) {
return db.getCollection(name);
}
/**
* 自增Id
* @param idName 自增Id名称
* @return Id
*/
public Integer getAutoIncreaseID(String idName) {
BasicDBObject query = new BasicDBObject();
query.put("name", idName);
BasicDBObject update = new BasicDBObject();
update.put("$inc", new BasicDBObject("id", 1));
DBObject dbObject2 = getCollection("inc_ids").findAndModify(query,
null, null, false, update, true, true);
Integer id = (Integer) dbObject2.get("id");
return id;
}
/**
* 获取对象
* @param dbObject
* @return
*/
@Override
public synchronized DBObject getByObj(DBObject dbObject) {
return getCollection().findOne(dbObject);
}
/**
* 更新数据
* @param query 该数据的对象
* @param obj 更新的数据
* @return
*/
@Override
public synchronized Boolean update(DBObject query,DBObject obj) {
WriteResult rs = getCollection().update(query, obj);
return (Boolean) rs.getField("updatedExisting");
}
@Override
public void remove(DBObject obj) {
WriteResult result = getCollection().remove(obj);
}
}
public class Test {
public static void main(String[] args) {
MongoService userDAO = new MongoServiceImpl("account", "test");
System.out.println("=============insert===============");
DBObject obj = new BasicDBObject();
obj.put("name", "aaa");
obj = userDAO.insert("test_id", obj);
System.out.println("=============get===============");
DBObject objGet = new BasicDBObject();
objGet.put("name", "aaa");
objGet = userDAO.getByObj(objGet);
System.out.println("=============set===============");
DBObject objAdd = new BasicDBObject();
objAdd.put("age2", "ag2444");
userDAO.update(obj, new BasicDBObject("$set", objAdd));
System.out.println("=============集合===============");
DBObject objArrays = new BasicDBObject();
objArrays.put("arrays", new BasicDBObject("array1", "111"));
userDAO.update(obj, new BasicDBObject("$push", objArrays));
// userDAO.remove(new BasicDBObject("test_id", 1));
}
}
运行结果：
表test：
表inc_ids：
说明：
1.在inc_ids中记录各个表的id。每次执行
- DBObject dbObject2 = getCollection("inc_ids").findAndModify(query,
- null, null, false, update, true, true);
实现id++。在这里保留了mongodb自带的ObjectId，也可以用test_id直接替换_id。
2.仅对update做了简单的封装。update还有4种方法：
这4种方法是对db.collection.update( criteria, objNew, upsert, multi )做了扩展。说明如下：
criteria : update的查询条件，类似sql update查询内where后面的
objNew : update的对象和一些更新的操作符（如$,$inc...）等，也可以理解为sql update查询内set后面的
upsert : 这个参数的意思是，如果不存在update的记录，是否插入objNew,true为插入，默认是false，不插入。
multi : mongodb默认是false,只更新找到的第一条记录，如果这个参数为true,就把按条件查出来多条记录全部更新。
3.$push，$set等通过BasicDBObject对象的形式实现，如下：
- DBObject objAdd = new BasicDBObject();
- objAdd.put("age2", "ag2444");
- userDAO.update(obj, new BasicDBObject("$set", objAdd));
- userDAO.update(obj, new BasicDBObject("$push", objArrays));
可同样适用在其他的命令。
参考资料：
http://hi.baidu.com/farmerluo/blog/item/9a23cb13a819bb2fdd540188.html——《MongoDB update数据语法》
http://www.kafka0102.com/2011/03/435.html——《理解mongodb的ObjectId》
http://blog.csdn.net/thomescai(转载请保留)