MongoDB2.6, java Usage Details

Source: Internet
Author: User

The environment used in this article is: win7_64 + Eclipse + maven
I. Preparations

Download the java driver package

Driver Pack:



Ii. Install Mongo

1. Installation Method in windows:

  Install the Mongo database:

Step 1: Download the installation package: if it is a Windows system, check whether it is a 64-bit or 32-bit version. Select the correct version.

Step 2: Create the directory "D: \ mongodb.pdf", decompress the downloaded installation package, find the directory "all-part. EXE", and copy it to the directory you just created.

Step 3: create a "data" folder under the "D: \ MongoDB" Directory, which will be used as the root folder for data storage.

  Configure the Mongo Server:

Open the CMD window and enter the command as follows:
> D:
> Cd D: \ MongoDB
> Mongod -- dbpath D: \ MongoDB \ data

After successful startup, access: http: // localhost: 27017/from the browser/

Indicates that mongodb in windows has been started successfully;

2. linux installation method:

After downloading and decompressing the package, make sure that the remaining space in the database directory is 3 GB or above;

Start with the configuration file: create a file named mongodb. conf in the root directory of mongodb. The content is as follows:

# Fork = true # Run as a daemon, create a server process # master = true # set as the master server for a single master-slave configuration # salve = true # set as the slave server for a single master-slave configuration # replSet = blort # Set the full set name # shardsvr = true # Set whether to slice # repairpath =/mongodb2.6.3/repair # pidfilepath =/mongodb2.6.3/mongodb. pid # sysinfo = true # verbose = true # cpu = true # Network and security set # Management # nohttpinterface = true # rest = true # syncdelay = 5 # Directory and relavent set dbpath =/ mongodb2.6.3/data # Database path logpath =/mongodb2.6.3/logs/mongodb. log # log output file path logappend = true # log output mode directoryperdb = true noauth = true port = 8888 # port number maxConns = 1024 fork = true quota = true quotaFiles = 1024 nssize = 16

The startup method is as follows:/mongodb2.6.3/bin/mongod-f/mongodb2.6.3/mongodb. conf
Remember to enable the linux Access Port:

# Vi/etc/sysconfig/iptables

Yy copy a row

P Paste

Modify Port

# Service iptables restart

Set auto-start

# Echo/mongodb2.6.3/bin/mongod-f/mongodb2.6.3/mongodb. config>/etc/rc. local

After the database is started, create the database and set:

Mongo -- port 8888

> Show dbs
Admin (empty)
Local 0.078 GB
> Use admin (switch Management User)
Switched to db admin
> Db. mymongo (create database)
Admin. mymongo
> Db. addUser ("root", "root") (Add User)
WARNING: The 'adduser' shell helper is DEPRECATED. Please use 'createuser' instead
Successfully added user: {"user": "root", "roles": ["root"]}
> Db. auth ("root", "root") (add Login User)
> Db. createCollection ("t_users") (add table)
{"OK": 1}
> Show collections (display table)
System. indexes
System. users
System. version
> Db. ({age: 21}) (store data)
WriteResult ({"nInserted": 1 })
> Db. t_users.find () (query all data)
{"_ Id": ObjectId ("53a2e45e4a674863b4ac5398"), "age": 21}

Mongodb deletes a database

Use mymongo;

Db. dropDatabase ();


Mongodb table Deletion

Db. t_users.drop ();

MongoDB Service stopped:
In linux, if you stop many services and like to directly kill-9 PID, But if you execute kill-9 PID for MongoDB, an error may be prompted at the next startup, resulting in service failure, in this case, run the following command:

Java code
  1. Rm-f/app/hadoop/db/mongod. lock
Delete the mongod. lock file in the specified data directory.

Normal stop method:
Kill-2 PID
Java code
  1. ./Mongo-host ip: port
Connect the service to be stopped first, and then:
Java code
  1. > Use admin
  2. > Db. shutdownServer ();

In this way, the service can be stopped normally.

Iii. Java MongoDB operation example

1. Create Test. java to complete simple mongoDB database operations

Try {Mongo mg = new Login client ("", 8888); DB db DB = mg. getDB ("mymongo"); // used to determine user logon // if (! Db. authenticate ("sdap", "sdap123 ". toCharArray () {// The method is no longer recommended. //} Set <String> collectionNames = db. getCollectionNames (); for (String string: collectionNames) {System. out. println (string);} DBCollection collection2 = db. getCollection ("t_users2"); collection2 = db. getCollection ("t_users2"); CarPasitionObj u = new CarPasitionObj (); u. setLa (1231d); u. setLo (42342d); u. setPn (" 1aaa"); u. setTp (12); String obj2Json = JsonUtils. getSingletonInstance (). obj2Json (u); BasicDBObject dbObject1 = new BasicDBObject (); dbObject1.put ("key", "123131"); Aggregate ("value", obj2Json); (dbObject1 ); <pre name = "code" class = "java"> BasicDBObject dbObject = new BasicDBObject (); dbObject. put ("key", "123131"); DBCursor find = collection2.find (dbObject); while (find. hasNext () {DBObject next = find. next (); String key = (String) next. get ("key"); String json = (String) next. get ("value"); System. out. println (key); CarPasitionObj formJson = JsonUtils. getSingletonInstance (). formJson (json, CarPasitionObj. class); System. out. println (formJson. getPn () ;}} catch (UnknownHostException e) {e. printStackTrace ();}

The following is my mongodb tool class:

/*** Project Name: main * File Name: MongodbCacheManagerUtil. java * Package Name: com. hdsx. taxi. driver. cq. cache * Date: April 9, 2014 12:49:55 * Copyright (c) 2014, sid Jenkins All Rights Reserved. * **/package com. hdsx. taxi. driver. cq. mongodb; import unknownHostException; import java. util. arrayList; import java. util. list; import org. apache. log4j. logger; import com. hdsx. taxi. driver. cq. module. initServletModule; import com. hdsx. taxi. driver. cq. tcp. util. jsonUtils; 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. using client;/*** ClassName: MongodbCacheManagerUtil * Function: todo add function. * Reason: todo add reason. * Date: April 9, 2014 12:49:55 * @ author sid * @ see */public class MongodbManagerUtil {private static final Logger logger = Logger. getLogger (MongodbManagerUtil. class); private Mongo mg = null; private DB db = null; private volatile static MongodbManagerUtil singleton = null; public static final String KEY = "key "; public static final String VALUE = "value"; public static MongodbManagerUtil getSingletonInstance () {if (singleton = null) {synchronized (MongodbManagerUtil. class) {if (singleton = null) {singleton = new MongodbManagerUtil () ;}} singleton = new MongodbManagerUtil ();} return singleton;} private MongodbManagerUtil () {if (logger. isDebugEnabled () {logger. debug ("MongodbCacheManagerUtil ()-start"); // $ NON-NLS-1 $} try {mg = new MongoClient ("", 8888); db = mg. getDB ("mymongo");} catch (UnknownHostException e) {e. printStackTrace ();} if (logger. isDebugEnabled () {logger. debug ("MongodbCacheManagerUtil ()-end"); // $ NON-NLS-1 $}/*** getCache :( get cache object ). ** @ author sid * @ param name * @ return */public DBCollection getCache (String name) {return this. db. getCollection (name);}/***** put :( Add the object to be cached to the specified cache object ). ** @ author sid * @ param cacheName * @ param key * @ param value */public void put (String cacheName, String key, Object value) {DBCollection cache = this. db. getCollection (cacheName); String obj2Json = JsonUtils. 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 :( get the object from the specified cache object based on the key ). ** @ author sid * @ param cacheName * @ param key * @ return */public <T> T get (String cacheName, String key, Class <T> classOfT) {DBCollection cache = this. db. getCollection (cacheName); List <DBObject> 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 :( clear the object from the specified cache object ). ** @ 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 :( get keys list ). ** @ author sid * @ param cacheName * @ return */public List <String> getKeys (String cacheName) {List <String> list = new ArrayList <String> (); 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: (determines whether a message exists ). ** @ 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 ;}}}
Besides save, insert, update, mongodb, and remove

The find method can specify the query conditions:

Greater than or equal to: $ gte

Less than or equal to: $ lte

Not equal to: $ ne

Demo: users. find (new BasicDBObject ("age", new BasicDBObject ("$ gte", 24 )))


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