A simple example of the Java Operation MongoDB Database

First import the MongoDB jar package Http://pan.baidu.com/s/1bnGMJRD

Database.java

Package com.mongodb.test;

Import java.net.UnknownHostException;

Import Com.mongodb.DB;
Import com.mongodb.DBCollection;
Import Com.mongodb.DBCursor;
Import Com.mongodb.DBObject;
Import Com.mongodb.Mongo;
Import com.mongodb.MongoException;
Import Com.mongodb.util.JSON;

public class DataBase {
public static void Main (string[] args)
Throws Unknownhostexception, Mongoexception {
1. Create a MONGO database connection object
Mongo mg = new Mongo ("127.0.0.1:27017");
Query all the database
For (String name:mg.getDatabaseNames ()) {
System.out.println ("DbName:" + name);
}
2. Create a connection to the related database
DB db = Mg.getdb ("Foobar");
Querying all collections of a database
For (String name:db.getCollectionNames ()) {
System.out.println ("CollectionName:" + name);
}

Dbcollection users = db.getcollection ("persons");
Querying all the data
Dbcursor cur = users.find ();
while (Cur.hasnext ()) {
DBObject object = Cur.next ();
System.out.println (Object.get ("name"));
}
System.out.println (Cur.count ());
System.out.println (Cur.getcursorid ());
System.out.println (json.serialize (cur));
}
}
Mongodb.java

Package com.mongodb.test;

Import java.net.UnknownHostException;
Import java.util.List;

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;

public class MongoDb {
1. Create a MONGO database connection object
static Mongo connection = NULL;
2. Create a connection to the related database
static DB db = null;
Public MongoDb (String dbName) throws Unknownhostexception, mongoexception{
Connection = new Mongo ("127.0.0.1:27017");
db = Connection.getdb (dbName);
}
public static void Main (string[] args) throws Unknownhostexception, Mongoexception {
Instantiation of
MongoDB MongoDB = new MongoDB ("Foobar");
/**
* 1. Create a database named JAVADB
*/
Mongodb.createcollection ("javadb");
/**
* 2. Add a piece of data to the collection javadb
*/
DBObject dbs = new Basicdbobject ();
Dbs.put ("name", "uspcat.com");
Dbs.put ("Age", 2);
list<string> books = new Arraylist<string> ();
Books.add ("ExtJS");
Books.add ("MONGODB");
Dbs.put ("Books", books);
Mongodb.insert (DBS, "javadb");
/**
* 3. BULK INSERT Data
*/
list<dbobject> dbobjects = new arraylist<dbobject> ();
DBObject jim = new Basicdbobject ("name", "Jim");
DBObject lisi = new Basicdbobject ("name", "Lisi");
Dbobjects.add (Jim);
Dbobjects.add (Lisi);
Mongodb.insertbatch (dbobjects, "javadb");
/**
* 4. Delete data based on ID
*/
Mongodb.deletebyid ("502870dab9c368bf5b151a04", "javadb");
/**
* 5. Delete data based on criteria
*/
DBObject lisi = new Basicdbobject ();
Lisi.put ("name", "Lisi");
int count = Mongodb.deletebydbs (Lisi, "javadb");
System.out.println ("The number of strips of data deleted is:" +count);
/**
* 6. Update operation, add email properties to the collection
*/
DBObject update = new Basicdbobject ();
Update.put ("$set",
New Basicdbobject ("Eamil", "Test @126.com"));
Mongodb.update (New Basicdbobject (),
Update,false,true, "javadb");
/**
* 7. Query the name and age in the persons collection
*/
DBObject keys = new Basicdbobject ();
Keys.put ("_id", false);
Keys.put ("name", true);
Keys.put ("Age", true);
dbcursor cursor = Mongodb.find (null, keys, "persons");
while (Cursor.hasnext ()) {
DBObject object = Cursor.next ();
System.out.println (Object.get ("name"));
//     }
/**
* 7. Check out age is more than 26 years old and English score is less than 80
*/
DBObject ref = new Basicdbobject ();
Ref.put ("Age", New Basicdbobject ("$gte", 26));
Ref.put ("E", New Basicdbobject ("$lte", 80));
dbcursor cursor = Mongodb.find (ref, NULL, "persons");
while (Cursor.hasnext ()) {
DBObject object = Cursor.next ();
System.out.print (Object.get ("name") + "--");
System.out.print (Object.get ("age") + "--");
System.out.println (Object.get ("E"));
//     }
/**
* 8. Pagination Example
*/
dbcursor cursor = Mongodb.find (null, NULL, 0, 3, "persons");
while (Cursor.hasnext ()) {
DBObject object = Cursor.next ();
System.out.print (Object.get ("name") + "--");
System.out.print (Object.get ("age") + "--");
System.out.println (Object.get ("E"));
}
Close the Connection object
Connection.close ();
}
/**
* Wear pieces a database collection
* @param collname Collection name
* @param DB Database instance
*/
public void CreateCollection (String collname) {
DBObject dbs = new Basicdbobject ();
Db.createcollection ("Javadb", DBS);
}
/**
* Add data for the corresponding collection
* @param DBS
* @param collname
*/
public void Insert (DBObject dbs,string collname) {
1. Get the collection
Dbcollection coll = db.getcollection (collname);
2. Insert operation
Coll.insert (DBS);
}
/**
* Bulk INSERT data for collections
* @param dbses
* @param collname
*/
public void Insertbatch (list<dbobject> dbses,string collname) {
1. Get the collection
Dbcollection coll = db.getcollection (collname);
2. Insert operation
Coll.insert (dbses);
}
/**
* Delete data by ID
* @param ID
* @param collname
* @return Returns the number of data bars affected
*/
public int Deletebyid (String id,string collname) {
1. Get the collection
Dbcollection coll = db.getcollection (collname);
DBObject dbs = new Basicdbobject ("_id", new ObjectId (ID));
int count = Coll.remove (DBS). GETN ();
return count;
}
/**
* Delete data based on criteria
* @param ID
* @param collname
* @return Returns the number of data bars affected
*/
public int Deletebydbs (dbobject dbs,string collname) {
1. Get the collection
Dbcollection coll = db.getcollection (collname);
int count = Coll.remove (DBS). GETN ();
return count;
}
/**
* Update Data
* @param find Finder
* @param Update Updater
* @param upsert Update or insert
* @param multi whether batch update
* @param collname Collection name
* @return Returns the number of data bars affected
*/
public int update (DBObject find,
DBObject Update,
Boolean Upsert,
Boolean Multi,
String collname) {
1. Get the collection
Dbcollection coll = db.getcollection (collname);
int count = coll.update (Find, Update, Upsert, multi). GETN ();
return count;
}
/**
* Finder (paging)
* @param ref
* @param keys
* @param start
* @param limit
* @return
*/
Public dbcursor Find (dbobject ref,
DBObject Keys,
int start,
int limit,
String collname) {
Dbcursor cur = find (ref, keys, collname);
return Cur.limit (limit). Skip (start);
}
/**
* Finder (no paging)
* @param ref
* @param keys
* @param start
* @param limit
* @param collname
* @return
*/
Public dbcursor Find (dbobject ref,
DBObject Keys,
String collname) {
1. Get the collection
Dbcollection coll = db.getcollection (collname);
Dbcursor cur = coll.find (ref, keys);
return cur;
}
}

Java operating a simple instance of the MongoDB database