Java connection, manipulating MongoDB

Java Connection MongoDB is very simple, specifically 2 steps:
1: Import the Java-mongo driver package to the new project
:

2: Create a link helper class to complete the link operation

Packagecom. YC. MongoDB;Import Java. Util. Iterator;Import Java. Util. Set;Importcom. MongoDB. Basicdbobject;Importcom. MongoDB. DB;Importcom. MongoDB. Dbcollection;Importcom. MongoDB. Dbcursor;Importcom. MongoDB. DBObject;Importcom. MongoDB. Mongo;Importcom. MongoDB. Writeresult;public class MongoLink2 {public static void main (string[] args) {Mongo mongo=null;DB Db=null;try {//link MONGO Server Mongo=new MONGO ("127.0.0.1",27017);DB objects are obtained from the name of the MongoDB database, and the database is connected to YC Db=mongo. Getdb("YC");Send GET Request db. Requeststart();Get its collectionSet<String> collections=db. Getcollectionnames();Iterator itr=collections. Iterator();Iterate output information while (ITR. Hasnext()) {System. out. println(ITR. Next());} dbcollection dbobject=db. GetCollection("YC");DBObject Object=null;Add Object=new basicdbobject ();Object. Put("_id",1003);Object. Put("Name","Zhang San");Object. Put("Sex","Male");Writeresult Rs=dbobject. Insert(object);Object. Put("_id",1002);Remove DBObject. Remove(New Basicdbobject ());Find All Dbcursor Cursor=dbobject. Find();while (cursor. Hasnext()) {Object=cursor. Next();System. out. println(object);}} catch (Exception e) {E. Printstacktrace();}finally{if (mongo!=null) {MONGO. Close();}        }    }}

The results of the operation are as follows:

At this point, actually already can use, the code coupling is too high, the function bundle is too serious, inconvenient to call,
It is then encapsulated.

Define a property file first:

It defines some basic configuration, such as user name, database name, IP, port, etc.
Next, define a class to read its files. The document is best defined as a singleton,

 PackageCom.yc.mongodb;ImportJava.io.IOException;ImportJava.io.InputStream;ImportJava.util.Properties;@SuppressWarnings("Serial") Public  class mypro extends Properties{    Private StaticMypro instanece=NewMypro ();Private Mypro() {InputStream Is=mypro.class.getresourceasstream ("/db.properties");Try{ This. Load (IS); }Catch(IOException e)        {E.printstacktrace (); }finally{if(is!=NULL){Try{Is.close (); }Catch(IOException e)                {E.printstacktrace (); }            }        }    } Public StaticMyprogetinstance(){returnInstanece; }}

Define a DBHelper class like Oracle to enable encapsulation of data operations:
As follows:

 PackageCom.yc.mongodb;ImportJava.net.UnknownHostException;ImportCom.mongodb.DB;ImportCom.mongodb.DBCollection;ImportCom.mongodb.Mongo;ImportCom.mongodb.MongoException; Public  class dbhelper {    Private StaticMongo mongo=NULL;PrivateDB db=NULL;PrivateDbcollection collection=NULL;Static{Try{mongo=NewMongo (Mypro.getinstance (). GetProperty ("IP"), Integer.parseint (Mypro.getinstance (). GetProperty ("Port"))); }Catch(NumberFormatException e)            {E.printstacktrace (); }Catch(Unknownhostexception e)            {E.printstacktrace (); }Catch(Mongoexception e)            {E.printstacktrace ();    } System.out.println (MONGO); }/** * * @param dbName * @param name * @param pwd * @return */     Public Boolean Getdb(String dbname,string name,string pwd) {Db=mongo.getdb (dbName);if(name!=NULL&&!"". Equals (name) &&pwd!=NULL&&!"". Equals (PWD) {if(Db.authenticate (name, Pwd.tochararray ())) {return true; }Else{return false; }        }Else{//See if a user name and password are given in the configuration fileString uname=mypro.getinstance (). GetProperty ("Uname"); String pwds=mypro.getinstance (). GetProperty ("Password");if(uname!=NULL&&!"". Equals (uname) &&pwds!=NULL&&!"". Equals (PWDs)) {if(Db.authenticate (uname, Pwds.tochararray ())) {return true; }Else{return false; }            }        }return true; }/** * Close connection * @param MONGO */     Public void CloseAll(Mongo Mongo) {if(mongo!=NULL) {mongo.close (); }    }}//using method overloading to implement different cases of the parameters/** * Gets the specified collection * @param CollectionName: The collection to be linked * @param dbName: The database where the collection resides * @return      */     PublicDbcollectiongetdbcollection(String collectionname,string DbName) {dbcollection dbcollection=NULL;if(Getdb (DbName,NULL,NULL)) {Db.requeststart ();if(collectionname==NULL){//If empty, look in the configuration fileCollectionname=mypro.getinstance (). GetProperty ("CollectionName");        } dbcollection=db.getcollection (CollectionName); }Else{//Throw exception            Throw NewRuntimeException ("Database connection Failed"); }returnDbcollection; }/** * * @param collectionname * @param dbName * @param name * @par AM Password * @return * *     PublicDbcollectiongetdbcollection(String collectionname,string dbname,string name,string password) {dbcollection dbcollection=NULL;if(Getdb (dbname,name, password)) {Db.requeststart ();if(collectionname==NULL){//If empty, look in the configuration fileCollectionname=mypro.getinstance (). GetProperty ("CollectionName");        } dbcollection=db.getcollection (CollectionName); }Else{//Throw exception            Throw NewRuntimeException ("Database connection Failed"); }returnDbcollection; }/** * Only Pass collection name * @param collectionname * @return * *     PublicDbcollectiongetdbcollection(String CollectionName) {dbcollection dbcollection=NULL; String dbname=mypro.getinstance (). GetProperty ("DbName");if(Getdb (DbName,NULL,NULL)) {Db.requeststart ();if(collectionname==NULL){//If empty, look in the configuration fileCollectionname=mypro.getinstance (). GetProperty ("CollectionName");        } dbcollection=db.getcollection (CollectionName); }Else{//Throw exception            Throw NewRuntimeException ("Database connection Failed"); }returnDbcollection; }

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Java connection, manipulating MongoDB