MongoDB using Java Part 3 - select

package mongodb;

import java.util.ArrayList;
import java.util.List;
import java.net.UnknownHostException;

import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.MongoCredential;
import com.mongodb.MongoClient;
import com.mongodb.ServerAddress;

public class MongodbSelect {

 public static void main(String[] args) {
  // TODO Auto-generated method stub
  try
  {
   // 認證
   MongoCredential journaldevAuth = MongoCredential.createMongoCRCredential("your username", "your database", "your password".toCharArray());
   List auths = new ArrayList();
   auths.add(journaldevAuth);

   //連線
   ServerAddress serverAddress = new ServerAddress("your server", your port);
   MongoClient mongo = new MongoClient(serverAddress,auths);

   //選擇連線database
   DB db = mongo.getDB("your database");

   //選擇collection (table)
   DBCollection site = db.getCollection("site");

   //iterate the table
   System.out.println();
   System.out.println("iterate the table");
   DBCursor cursor = site.find();
   try {
    while(cursor.hasNext()) {
     System.out.println(cursor.next());
    }
   } finally {
    cursor.close();
   }

   //query -->  city==Taipei
   System.out.println();
   System.out.println("query -->  city==Taipei");
   BasicDBObject query = new BasicDBObject("city", "taipei");

   cursor = site.find(query);

   try {
    while(cursor.hasNext()) {
     System.out.println(cursor.next());
    }
   } finally {
    cursor.close();
   }

   //query --> num>=50 && city==Taipei
   System.out.println();
   System.out.println("query --> num>=50 && city==Taipei");
   query = new BasicDBObject("num", new BasicDBObject("$gte", 50))
   .append("city", "taipei");

   cursor = site.find(query);

   try {
    while(cursor.hasNext()) {
     System.out.println(cursor.next());
    }
   } finally {
    cursor.close();
   }
   
   //query num > 20 && num<=30
   //only display columns city , address
   System.out.println();
   System.out.println("query num > 20 && num<=30");
   System.out.println("only display columns city , address");
   query = new BasicDBObject("num", new BasicDBObject("$gt", 20).append("$lte", 30));
   cursor = site.find(query, new BasicDBObject("city",true).append("address", true));

   try {
       while (cursor.hasNext()) {
           System.out.println(cursor.next());
       }
   } finally {
       cursor.close();
   }
   
   //iterate the table and sort by num
   System.out.println();
   System.out.println("iterate the table and sort by num");
      cursor = site.find().sort(new BasicDBObject("num",1));
   try {
    while(cursor.hasNext()) {
     System.out.println(cursor.next());
    }
   } finally {
    cursor.close();
   }
  }
  catch(UnknownHostException ex)
  {

  }
 }

}